307 files changed, 3632 insertions, 1590 deletions

diff --git a/tests/alloc.c b/tests/alloc.c
new file mode 100644
index 0000000..6c0defd
--- /dev/null
+++ b/tests/alloc.c
@@ -0,0 +1,52 @@
+// Copyright © Tavian Barnes <tavianator@tavianator.com>
+// SPDX-License-Identifier: 0BSD
+
+#include "prelude.h"
+#include "tests.h"
+#include "alloc.h"
+#include "diag.h"
+#include <errno.h>
+#include <stdlib.h>
+#include <stdint.h>
+
+bool check_alloc(void) {
+	bool ret = true;
+
+	// Check sizeof_flex()
+	struct flexible {
+		alignas(64) int foo[8];
+		int bar[];
+	};
+	ret &= bfs_check(sizeof_flex(struct flexible, bar, 0) >= sizeof(struct flexible));
+	ret &= bfs_check(sizeof_flex(struct flexible, bar, 16) % alignof(struct flexible) == 0);
+
+	size_t too_many = SIZE_MAX / sizeof(int) + 1;
+	ret &= bfs_check(sizeof_flex(struct flexible, bar, too_many) == align_floor(alignof(struct flexible), SIZE_MAX));
+
+	// Corner case: sizeof(type) > align_ceil(alignof(type), offsetof(type, member))
+	// Doesn't happen in typical ABIs
+	ret &= bfs_check(flex_size(8, 16, 4, 4, 1) == 16);
+
+	// Make sure we detect allocation size overflows
+#if __GNUC__ && !__clang__
+#  pragma GCC diagnostic ignored "-Walloc-size-larger-than="
+#endif
+
+	ret &= bfs_check(ALLOC_ARRAY(int, too_many) == NULL && errno == EOVERFLOW);
+	ret &= bfs_check(ZALLOC_ARRAY(int, too_many) == NULL && errno == EOVERFLOW);
+	ret &= bfs_check(ALLOC_FLEX(struct flexible, bar, too_many) == NULL && errno == EOVERFLOW);
+	ret &= bfs_check(ZALLOC_FLEX(struct flexible, bar, too_many) == NULL && errno == EOVERFLOW);
+
+	// varena tests
+	struct varena varena;
+	VARENA_INIT(&varena, struct flexible, bar);
+
+	for (size_t i = 0; i < 256; ++i) {
+		bfs_verify(varena_alloc(&varena, i));
+		struct arena *arena = &varena.arenas[varena.narenas - 1];
+		ret &= bfs_check(arena->size >= sizeof_flex(struct flexible, bar, i));
+	}
+
+	varena_destroy(&varena);
+	return ret;
+}
diff --git a/tests/bfs/D_incomplete.sh b/tests/bfs/D_incomplete.sh
index 396d365..30c522a 100644
--- a/tests/bfs/D_incomplete.sh
+++ b/tests/bfs/D_incomplete.sh
@@ -1 +1 @@
-fail invoke_bfs -D
+! invoke_bfs -D
diff --git a/tests/bfs/D_opt.out b/tests/bfs/D_opt.out
new file mode 100644
index 0000000..6218a0c
--- /dev/null
+++ b/tests/bfs/D_opt.out
@@ -0,0 +1,7 @@
+basic/a
+basic/b
+basic/c/d
+basic/e/f
+basic/j/foo
+basic/k/foo/bar
+basic/l/foo/bar/baz
diff --git a/tests/bfs/D_opt.sh b/tests/bfs/D_opt.sh
new file mode 100644
index 0000000..c14fe70
--- /dev/null
+++ b/tests/bfs/D_opt.sh
@@ -0,0 +1 @@
+bfs_diff -D opt -nohidden -not \( -type c -o -type d \) -links -5 -links -10 -not -hidden basic
diff --git a/tests/bfs/D_unknown.sh b/tests/bfs/D_unknown.sh
index e3614ba..cac9bd9 100644
--- a/tests/bfs/D_unknown.sh
+++ b/tests/bfs/D_unknown.sh
@@ -1,4 +1,4 @@
 stderr=$(invoke_bfs -warn -D unknown basic 2>&1 >"$OUT")
-[ -n "$stderr" ] || return 1
+[ -n "$stderr" ]
 sort_output
 diff_output
diff --git a/tests/bfs/L_capable.out b/tests/bfs/L_capable.out
index e5ba3c7..0810d4a 100644
--- a/tests/bfs/L_capable.out
+++ b/tests/bfs/L_capable.out
@@ -1,2 +1,2 @@
-scratch/capable
-scratch/link
+./capable
+./link
diff --git a/tests/bfs/L_capable.sh b/tests/bfs/L_capable.sh
index 533ac2f..97c404f 100644
--- a/tests/bfs/L_capable.sh
+++ b/tests/bfs/L_capable.sh
@@ -1,12 +1,10 @@
-skip_unless test "$SUDO"
-skip_unless test "$UNAME" = "Linux"
+test "$UNAME" = "Linux" || skip
+invoke_bfs . -quit -capable || skip
 
-clean_scratch
+cd "$TEST"
 
-skip_unless invoke_bfs scratch -quit -capable
+"$XTOUCH" normal capable
+bfs_sudo setcap all+ep capable || skip
+ln -s capable link
 
-"$XTOUCH" scratch/{normal,capable}
-sudo setcap all+ep scratch/capable
-ln -s capable scratch/link
-
-bfs_diff -L scratch -capable
+bfs_diff -L . -capable
diff --git a/tests/bfs/O9.sh b/tests/bfs/O9.sh
index 12f6c2d..c12a7a3 100644
--- a/tests/bfs/O9.sh
+++ b/tests/bfs/O9.sh
@@ -1,4 +1,4 @@
 stderr=$(invoke_bfs -warn -O9 basic 2>&1 >"$OUT")
-[ -n "$stderr" ] || return 1
+[ -n "$stderr" ]
 sort_output
 diff_output
diff --git a/tests/bfs/and_incomplete.sh b/tests/bfs/and_incomplete.sh
index f7bc2c3..05abc2d 100644
--- a/tests/bfs/and_incomplete.sh
+++ b/tests/bfs/and_incomplete.sh
@@ -1 +1 @@
-fail invoke_bfs -print -a
+! invoke_bfs -print -a
diff --git a/tests/bfs/capable.out b/tests/bfs/capable.out
index 78b5bd9..ac7b5ce 100644
--- a/tests/bfs/capable.out
+++ b/tests/bfs/capable.out
@@ -1 +1 @@
-scratch/capable
+./capable
diff --git a/tests/bfs/capable.sh b/tests/bfs/capable.sh
index 256b9bc..35bb0b4 100644
--- a/tests/bfs/capable.sh
+++ b/tests/bfs/capable.sh
@@ -1,12 +1,10 @@
-skip_unless test "$SUDO"
-skip_unless test "$UNAME" = "Linux"
+test "$UNAME" = "Linux" || skip
+invoke_bfs . -quit -capable || skip
 
-clean_scratch
+cd "$TEST"
 
-skip_unless invoke_bfs scratch -quit -capable
+"$XTOUCH" normal capable
+bfs_sudo setcap all+ep capable || skip
+ln -s capable link
 
-"$XTOUCH" scratch/{normal,capable}
-sudo setcap all+ep scratch/capable
-ln -s capable scratch/link
-
-bfs_diff scratch -capable
+bfs_diff . -capable
diff --git a/tests/bfs/closed_stderr.sh b/tests/bfs/closed_stderr.sh
new file mode 100644
index 0000000..26abd85
--- /dev/null
+++ b/tests/bfs/closed_stderr.sh
@@ -0,0 +1,4 @@
+# Check if the platform automatically re-opens stderr before we can
+(bash -c 'echo >&2' 2>&-) && skip
+
+! invoke_bfs basic >&- 2>&-
diff --git a/tests/posix/closed_stdin.out b/tests/bfs/closed_stdin.out
index a7ccfe4..a7ccfe4 100644
--- a/tests/posix/closed_stdin.out
+++ b/tests/bfs/closed_stdin.out
diff --git a/tests/posix/closed_stdin.sh b/tests/bfs/closed_stdin.sh
index 6932be8..6932be8 100644
--- a/tests/posix/closed_stdin.sh
+++ b/tests/bfs/closed_stdin.sh
diff --git a/tests/bfs/closed_stdout.sh b/tests/bfs/closed_stdout.sh
new file mode 100644
index 0000000..5b6f7c3
--- /dev/null
+++ b/tests/bfs/closed_stdout.sh
@@ -0,0 +1,4 @@
+# Check if the platform automatically re-opens stdout before we can
+(bash -c echo >&-) && skip
+
+! invoke_bfs basic >&-
diff --git a/tests/bfs/color.out b/tests/bfs/color.out
index 77fc8a8..a439814 100644
--- a/tests/bfs/color.out
+++ b/tests/bfs/color.out
@@ -1,3 +1,5 @@
+$'rainbow/\e[1m'
+$'rainbow/\e[1m/'$'\e[0m'
 rainbow
 rainbow/exec.sh
 rainbow/socket
@@ -13,8 +15,13 @@
 rainbow/sticky
 rainbow/file.dat
 rainbow/file.txt
+rainbow/lower.gz
+rainbow/lower.tar
+rainbow/lower.tar.gz
+rainbow/lu.tar.GZ
 rainbow/mh1
 rainbow/mh2
-rainbow/star.gz
-rainbow/star.tar
-rainbow/star.tar.gz
+rainbow/ul.TAR.gz
+rainbow/upper.GZ
+rainbow/upper.TAR
+rainbow/upper.TAR.GZ
diff --git a/tests/bfs/color_L.out b/tests/bfs/color_L.out
index b60dd4a..85923db 100644
--- a/tests/bfs/color_L.out
+++ b/tests/bfs/color_L.out
@@ -1,3 +1,5 @@
+$'rainbow/\e[1m'
+$'rainbow/\e[1m/'$'\e[0m'
 rainbow
 rainbow/exec.sh
 rainbow/chardev_link
@@ -13,8 +15,13 @@
 rainbow/file.dat
 rainbow/file.txt
 rainbow/link.txt
+rainbow/lower.gz
+rainbow/lower.tar
+rainbow/lower.tar.gz
+rainbow/lu.tar.GZ
 rainbow/mh1
 rainbow/mh2
-rainbow/star.gz
-rainbow/star.tar
-rainbow/star.tar.gz
+rainbow/ul.TAR.gz
+rainbow/upper.GZ
+rainbow/upper.TAR
+rainbow/upper.TAR.GZ
diff --git a/tests/bfs/color_L_ln_target.out b/tests/bfs/color_L_ln_target.out
index cd4ec5e..23fe8d7 100644
--- a/tests/bfs/color_L_ln_target.out
+++ b/tests/bfs/color_L_ln_target.out
@@ -1,3 +1,5 @@
+$'rainbow/\e[1m'
+$'rainbow/\e[1m/'$'\e[0m'
 rainbow
 rainbow/broken
 rainbow/exec.sh
@@ -13,8 +15,13 @@
 rainbow/file.dat
 rainbow/file.txt
 rainbow/link.txt
+rainbow/lower.gz
+rainbow/lower.tar
+rainbow/lower.tar.gz
+rainbow/lu.tar.GZ
 rainbow/mh1
 rainbow/mh2
-rainbow/star.gz
-rainbow/star.tar
-rainbow/star.tar.gz
+rainbow/ul.TAR.gz
+rainbow/upper.GZ
+rainbow/upper.TAR
+rainbow/upper.TAR.GZ
diff --git a/tests/bfs/color_L_no_stat.out b/tests/bfs/color_L_no_stat.out
index c0bb1be..72e0319 100644
--- a/tests/bfs/color_L_no_stat.out
+++ b/tests/bfs/color_L_no_stat.out
@@ -1,8 +1,7 @@
+$'rainbow/\e[1m'
+$'rainbow/\e[1m/'$'\e[0m'
 rainbow
 rainbow/chardev_link
-rainbow/ow
-rainbow/sticky
-rainbow/sticky_ow
 rainbow/socket
 rainbow/broken
 rainbow/file.txt
@@ -10,11 +9,19 @@
 rainbow/pipe
 rainbow/exec.sh
 rainbow/file.dat
+rainbow/lower.gz
+rainbow/lower.tar
+rainbow/lower.tar.gz
+rainbow/lu.tar.GZ
 rainbow/mh1
 rainbow/mh2
 rainbow/sgid
-rainbow/star.gz
-rainbow/star.tar
-rainbow/star.tar.gz
 rainbow/sugid
 rainbow/suid
+rainbow/ul.TAR.gz
+rainbow/upper.GZ
+rainbow/upper.TAR
+rainbow/upper.TAR.GZ
+rainbow/ow
+rainbow/sticky
+rainbow/sticky_ow
diff --git a/tests/bfs/color_star.out b/tests/bfs/color_auto.out
index 77fc8a8..a439814 100644
--- a/tests/bfs/color_star.out
+++ b/tests/bfs/color_auto.out
@@ -1,3 +1,5 @@
+$'rainbow/\e[1m'
+$'rainbow/\e[1m/'$'\e[0m'
 rainbow
 rainbow/exec.sh
 rainbow/socket
@@ -13,8 +15,13 @@
 rainbow/sticky
 rainbow/file.dat
 rainbow/file.txt
+rainbow/lower.gz
+rainbow/lower.tar
+rainbow/lower.tar.gz
+rainbow/lu.tar.GZ
 rainbow/mh1
 rainbow/mh2
-rainbow/star.gz
-rainbow/star.tar
-rainbow/star.tar.gz
+rainbow/ul.TAR.gz
+rainbow/upper.GZ
+rainbow/upper.TAR
+rainbow/upper.TAR.GZ
diff --git a/tests/bfs/color_auto.sh b/tests/bfs/color_auto.sh
new file mode 100644
index 0000000..7e875cc
--- /dev/null
+++ b/tests/bfs/color_auto.sh
@@ -0,0 +1,4 @@
+unset NO_COLOR
+bfs_pty rainbow >"$OUT"
+sort_output
+diff_output
diff --git a/tests/bfs/color_cd0_no.out b/tests/bfs/color_cd0_no.out
new file mode 100644
index 0000000..37b3fbc
--- /dev/null
+++ b/tests/bfs/color_cd0_no.out
@@ -0,0 +1,27 @@
+$'rainbow/\e[1m'
+$'rainbow/\e[1m/'$'\e[0m'
+rainbow
+rainbow/exec.sh
+rainbow/socket
+rainbow/broken
+rainbow/file.dat
+rainbow/file.txt
+rainbow/link.txt
+rainbow/lower.gz
+rainbow/lower.tar
+rainbow/lower.tar.gz
+rainbow/lu.tar.GZ
+rainbow/mh1
+rainbow/mh2
+rainbow/ul.TAR.gz
+rainbow/upper.GZ
+rainbow/upper.TAR
+rainbow/upper.TAR.GZ
+rainbow/sticky_ow
+rainbow/sgid
+rainbow/pipe
+rainbow/ow
+rainbow/sugid
+rainbow/suid
+rainbow/sticky
+rainbow/chardev_link
diff --git a/tests/bfs/color_cd0_no.sh b/tests/bfs/color_cd0_no.sh
new file mode 100644
index 0000000..325a782
--- /dev/null
+++ b/tests/bfs/color_cd0_no.sh
@@ -0,0 +1 @@
+LS_COLORS="ln=target:cd=0:no=01;92:" bfs_diff rainbow -color
diff --git a/tests/bfs/color_deep.out b/tests/bfs/color_deep.out
new file mode 100644
index 0000000..fb990d5
--- /dev/null
+++ b/tests/bfs/color_deep.out
@@ -0,0 +1,16 @@
+0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
diff --git a/tests/bfs/color_deep.sh b/tests/bfs/color_deep.sh
new file mode 100644
index 0000000..a83ee0e
--- /dev/null
+++ b/tests/bfs/color_deep.sh
@@ -0,0 +1,7 @@
+name="0123456789ABCDEF"
+name="${name}${name}${name}${name}"
+name="${name}${name}${name}${name}"
+name="${name:0:255}"
+export LS_COLORS="*${name}=01:"
+
+bfs_diff deep -color -type f -printf '%f\n'
diff --git a/tests/bfs/color_escapes.out b/tests/bfs/color_escapes.out
index b71e138..0bf9fbb 100644
--- a/tests/bfs/color_escapes.out
+++ b/tests/bfs/color_escapes.out
@@ -1,3 +1,5 @@
+:$'rainbow/\e[1m'
+:$'rainbow/\e[1m/'$'\e[0m'
 :rainbow
 :rainbow/:exec.sh
 :rainbow/:socket
@@ -13,8 +15,13 @@
 :rainbow/:sticky
 :rainbow/file.dat
 :rainbow/file.txt
+:rainbow/lower.gz
+:rainbow/lower.tar
+:rainbow/lower.tar.gz
+:rainbow/lu.tar.GZ
 :rainbow/mh1
 :rainbow/mh2
-:rainbow/star.gz
-:rainbow/star.tar
-:rainbow/star.tar.gz
+:rainbow/ul.TAR.gz
+:rainbow/upper.GZ
+:rainbow/upper.TAR
+:rainbow/upper.TAR.GZ
diff --git a/tests/bfs/color_ext.out b/tests/bfs/color_ext.out
index cf26e73..218100f 100644
--- a/tests/bfs/color_ext.out
+++ b/tests/bfs/color_ext.out
@@ -1,3 +1,5 @@
+$'rainbow/\e[1m'
+$'rainbow/\e[1m/'$'\e[0m'
 rainbow
 rainbow/exec.sh
 rainbow/socket
@@ -13,8 +15,13 @@
 rainbow/suid
 rainbow/sticky
 rainbow/file.dat
+rainbow/lower.gz
+rainbow/lower.tar
+rainbow/lower.tar.gz
+rainbow/lu.tar.GZ
 rainbow/mh1
 rainbow/mh2
-rainbow/star.gz
-rainbow/star.tar
-rainbow/star.tar.gz
+rainbow/ul.TAR.gz
+rainbow/upper.GZ
+rainbow/upper.TAR
+rainbow/upper.TAR.GZ
diff --git a/tests/bfs/color_ext0.out b/tests/bfs/color_ext0.out
index e764a6b..d2a7fd5 100644
--- a/tests/bfs/color_ext0.out
+++ b/tests/bfs/color_ext0.out
@@ -1,3 +1,5 @@
+$'rainbow/\e[1m'
+$'rainbow/\e[1m/'$'\e[0m'
 rainbow
 rainbow/file.txt
 rainbow/exec.sh
@@ -13,8 +15,13 @@
 rainbow/suid
 rainbow/sticky
 rainbow/file.dat
+rainbow/lower.gz
+rainbow/lower.tar
+rainbow/lower.tar.gz
+rainbow/lu.tar.GZ
 rainbow/mh1
 rainbow/mh2
-rainbow/star.gz
-rainbow/star.tar
-rainbow/star.tar.gz
+rainbow/ul.TAR.gz
+rainbow/upper.GZ
+rainbow/upper.TAR
+rainbow/upper.TAR.GZ
diff --git a/tests/bfs/color_ext_case.out b/tests/bfs/color_ext_case.out
new file mode 100644
index 0000000..93dc8f6
--- /dev/null
+++ b/tests/bfs/color_ext_case.out
@@ -0,0 +1,27 @@
+$'rainbow/\e[1m'
+$'rainbow/\e[1m/'$'\e[0m'
+rainbow
+rainbow/lower.gz
+rainbow/lower.tar.gz
+rainbow/exec.sh
+rainbow/upper.GZ
+rainbow/upper.TAR.GZ
+rainbow/lower.tar
+rainbow/upper.TAR
+rainbow/ul.TAR.gz
+rainbow/lu.tar.GZ
+rainbow/socket
+rainbow/broken
+rainbow/chardev_link
+rainbow/link.txt
+rainbow/sticky_ow
+rainbow/sgid
+rainbow/pipe
+rainbow/ow
+rainbow/file.txt
+rainbow/sugid
+rainbow/suid
+rainbow/sticky
+rainbow/file.dat
+rainbow/mh1
+rainbow/mh2
diff --git a/tests/bfs/color_ext_case.sh b/tests/bfs/color_ext_case.sh
new file mode 100644
index 0000000..4adba69
--- /dev/null
+++ b/tests/bfs/color_ext_case.sh
@@ -0,0 +1,6 @@
+# *.gz=01;31:*.GZ=01;32         -- case sensitive
+# *.tAr=01;33:*.TaR=01;33       -- case-insensitive
+# *.TAR.gz=01;34:*.tar.GZ=01;35 -- case-sensitive
+# *.txt=35:*TXT=36              -- case-insensitive
+export LS_COLORS="*.gz=01;31:*.GZ=01;32:*.tAr=01;33:*.TaR=01;33:*.TAR.gz=01;34:*.tar.GZ=01;35:*.txt=35:*TXT=36"
+bfs_diff rainbow -color
diff --git a/tests/bfs/color_ext_override.out b/tests/bfs/color_ext_override.out
index 1377b65..0acfcbc 100644
--- a/tests/bfs/color_ext_override.out
+++ b/tests/bfs/color_ext_override.out
@@ -1,8 +1,15 @@
+$'rainbow/\e[1m'
+$'rainbow/\e[1m/'$'\e[0m'
 rainbow
 rainbow/exec.sh
-rainbow/star.tar
-rainbow/star.gz
-rainbow/star.tar.gz
+rainbow/lower.tar
+rainbow/upper.TAR
+rainbow/lower.gz
+rainbow/lower.tar.gz
+rainbow/lu.tar.GZ
+rainbow/ul.TAR.gz
+rainbow/upper.GZ
+rainbow/upper.TAR.GZ
 rainbow/socket
 rainbow/broken
 rainbow/chardev_link
diff --git a/tests/bfs/color_ext_underride.out b/tests/bfs/color_ext_underride.out
index 787248a..5c98341 100644
--- a/tests/bfs/color_ext_underride.out
+++ b/tests/bfs/color_ext_underride.out
@@ -1,8 +1,15 @@
+$'rainbow/\e[1m'
+$'rainbow/\e[1m/'$'\e[0m'
 rainbow
-rainbow/star.tar.gz
+rainbow/lower.tar.gz
+rainbow/lu.tar.GZ
+rainbow/ul.TAR.gz
+rainbow/upper.TAR.GZ
 rainbow/exec.sh
-rainbow/star.tar
-rainbow/star.gz
+rainbow/lower.tar
+rainbow/upper.TAR
+rainbow/lower.gz
+rainbow/upper.GZ
 rainbow/socket
 rainbow/broken
 rainbow/chardev_link
diff --git a/tests/bfs/color_fi0_no.out b/tests/bfs/color_fi0_no.out
new file mode 100644
index 0000000..a439814
--- /dev/null
+++ b/tests/bfs/color_fi0_no.out
@@ -0,0 +1,27 @@
+$'rainbow/\e[1m'
+$'rainbow/\e[1m/'$'\e[0m'
+rainbow
+rainbow/exec.sh
+rainbow/socket
+rainbow/broken
+rainbow/chardev_link
+rainbow/link.txt
+rainbow/sticky_ow
+rainbow/sgid
+rainbow/pipe
+rainbow/ow
+rainbow/sugid
+rainbow/suid
+rainbow/sticky
+rainbow/file.dat
+rainbow/file.txt
+rainbow/lower.gz
+rainbow/lower.tar
+rainbow/lower.tar.gz
+rainbow/lu.tar.GZ
+rainbow/mh1
+rainbow/mh2
+rainbow/ul.TAR.gz
+rainbow/upper.GZ
+rainbow/upper.TAR
+rainbow/upper.TAR.GZ
diff --git a/tests/bfs/color_fi0_no.sh b/tests/bfs/color_fi0_no.sh
new file mode 100644
index 0000000..f947d64
--- /dev/null
+++ b/tests/bfs/color_fi0_no.sh
@@ -0,0 +1 @@
+LS_COLORS="fi=0:no=01;92:" bfs_diff rainbow -color
diff --git a/tests/bfs/color_fi_no.out b/tests/bfs/color_fi_no.out
new file mode 100644
index 0000000..1c1ad8e
--- /dev/null
+++ b/tests/bfs/color_fi_no.out
@@ -0,0 +1,27 @@
+$'rainbow/\e[1m'
+$'rainbow/\e[1m/'$'\e[0m'
+rainbow
+rainbow/exec.sh
+rainbow/socket
+rainbow/broken
+rainbow/chardev_link
+rainbow/link.txt
+rainbow/file.dat
+rainbow/file.txt
+rainbow/lower.gz
+rainbow/lower.tar
+rainbow/lower.tar.gz
+rainbow/lu.tar.GZ
+rainbow/mh1
+rainbow/mh2
+rainbow/ul.TAR.gz
+rainbow/upper.GZ
+rainbow/upper.TAR
+rainbow/upper.TAR.GZ
+rainbow/sticky_ow
+rainbow/sgid
+rainbow/pipe
+rainbow/ow
+rainbow/sugid
+rainbow/suid
+rainbow/sticky
diff --git a/tests/bfs/color_fi_no.sh b/tests/bfs/color_fi_no.sh
new file mode 100644
index 0000000..c2b4ec7
--- /dev/null
+++ b/tests/bfs/color_fi_no.sh
@@ -0,0 +1 @@
+LS_COLORS="fi=01;91:no=01;92:" bfs_diff rainbow -color
diff --git a/tests/bfs/color_ln_target.out b/tests/bfs/color_ln_target.out
index cd4ec5e..23fe8d7 100644
--- a/tests/bfs/color_ln_target.out
+++ b/tests/bfs/color_ln_target.out
@@ -1,3 +1,5 @@
+$'rainbow/\e[1m'
+$'rainbow/\e[1m/'$'\e[0m'
 rainbow
 rainbow/broken
 rainbow/exec.sh
@@ -13,8 +15,13 @@
 rainbow/file.dat
 rainbow/file.txt
 rainbow/link.txt
+rainbow/lower.gz
+rainbow/lower.tar
+rainbow/lower.tar.gz
+rainbow/lu.tar.GZ
 rainbow/mh1
 rainbow/mh2
-rainbow/star.gz
-rainbow/star.tar
-rainbow/star.tar.gz
+rainbow/ul.TAR.gz
+rainbow/upper.GZ
+rainbow/upper.TAR
+rainbow/upper.TAR.GZ
diff --git a/tests/bfs/color_ls.out b/tests/bfs/color_ls.out
index b08d894..f69eb9c 100644
--- a/tests/bfs/color_ls.out
+++ b/tests/bfs/color_ls.out
@@ -1,12 +1,12 @@
-scratch/foo/bar
-scratch/foo/bar
-/__bfs__/nowhere
-/__bfs__/nowhere
-foo/bar/baz/qux
-foo/bar/baz/qux
+scratch/foo/bar
+scratch/foo/bar
+/__bfs__/nowhere
+/__bfs__/nowhere
 foo/bar/nowhere
 foo/bar/nowhere
-foo/bar/nowhere/nothing
-foo/bar/nowhere/nothing
+foo/bar/nowhere/nothing
+foo/bar/nowhere/nothing
 foo/bar/baz
 foo/bar/baz
+foo/bar/baz//qux
+foo/bar/baz//qux
diff --git a/tests/bfs/color_ls.sh b/tests/bfs/color_ls.sh
index 37d088f..f1cc216 100644
--- a/tests/bfs/color_ls.sh
+++ b/tests/bfs/color_ls.sh
@@ -1,15 +1,15 @@
-clean_scratch
+cd "$TEST"
 "$XTOUCH" -p scratch/foo/bar/baz
 ln -s foo/bar/baz scratch/link
 ln -s foo/bar/nowhere scratch/broken
 ln -s foo/bar/nowhere/nothing scratch/nested
-ln -s foo/bar/baz/qux scratch/notdir
+ln -s foo/bar/baz//qux scratch/notdir
 ln -s scratch/foo/bar scratch/relative
 mkdir scratch/__bfs__
 ln -s /__bfs__/nowhere scratch/absolute
 
-LS_COLORS="or=01;31:" invoke_bfs scratch/{,link,broken,nested,notdir,relative,absolute} -color -type l -ls \
+export LS_COLORS="or=01;31:"
+invoke_bfs scratch/{,link,broken,nested,notdir,relative,absolute} -color -type l -ls \
     | sed 's/.* -> //' \
     | sort >"$OUT"
-
 diff_output
diff --git a/tests/bfs/color_mh.out b/tests/bfs/color_mh.out
index 757a6a1..c658082 100644
--- a/tests/bfs/color_mh.out
+++ b/tests/bfs/color_mh.out
@@ -1,3 +1,5 @@
+$'rainbow/\e[1m'
+$'rainbow/\e[1m/'$'\e[0m'
 rainbow
 rainbow/exec.sh
 rainbow/socket
@@ -15,6 +17,11 @@
 rainbow/sticky
 rainbow/file.dat
 rainbow/file.txt
-rainbow/star.gz
-rainbow/star.tar
-rainbow/star.tar.gz
+rainbow/lower.gz
+rainbow/lower.tar
+rainbow/lower.tar.gz
+rainbow/lu.tar.GZ
+rainbow/ul.TAR.gz
+rainbow/upper.GZ
+rainbow/upper.TAR
+rainbow/upper.TAR.GZ
diff --git a/tests/bfs/color_mh0.out b/tests/bfs/color_mh0.out
index 77fc8a8..a439814 100644
--- a/tests/bfs/color_mh0.out
+++ b/tests/bfs/color_mh0.out
@@ -1,3 +1,5 @@
+$'rainbow/\e[1m'
+$'rainbow/\e[1m/'$'\e[0m'
 rainbow
 rainbow/exec.sh
 rainbow/socket
@@ -13,8 +15,13 @@
 rainbow/sticky
 rainbow/file.dat
 rainbow/file.txt
+rainbow/lower.gz
+rainbow/lower.tar
+rainbow/lower.tar.gz
+rainbow/lu.tar.GZ
 rainbow/mh1
 rainbow/mh2
-rainbow/star.gz
-rainbow/star.tar
-rainbow/star.tar.gz
+rainbow/ul.TAR.gz
+rainbow/upper.GZ
+rainbow/upper.TAR
+rainbow/upper.TAR.GZ
diff --git a/tests/bfs/color_mi.out b/tests/bfs/color_mi.out
index 77fc8a8..a439814 100644
--- a/tests/bfs/color_mi.out
+++ b/tests/bfs/color_mi.out
@@ -1,3 +1,5 @@
+$'rainbow/\e[1m'
+$'rainbow/\e[1m/'$'\e[0m'
 rainbow
 rainbow/exec.sh
 rainbow/socket
@@ -13,8 +15,13 @@
 rainbow/sticky
 rainbow/file.dat
 rainbow/file.txt
+rainbow/lower.gz
+rainbow/lower.tar
+rainbow/lower.tar.gz
+rainbow/lu.tar.GZ
 rainbow/mh1
 rainbow/mh2
-rainbow/star.gz
-rainbow/star.tar
-rainbow/star.tar.gz
+rainbow/ul.TAR.gz
+rainbow/upper.GZ
+rainbow/upper.TAR
+rainbow/upper.TAR.GZ
diff --git a/tests/bfs/color_missing_colon.out b/tests/bfs/color_missing_colon.out
index cf26e73..218100f 100644
--- a/tests/bfs/color_missing_colon.out
+++ b/tests/bfs/color_missing_colon.out
@@ -1,3 +1,5 @@
+$'rainbow/\e[1m'
+$'rainbow/\e[1m/'$'\e[0m'
 rainbow
 rainbow/exec.sh
 rainbow/socket
@@ -13,8 +15,13 @@
 rainbow/suid
 rainbow/sticky
 rainbow/file.dat
+rainbow/lower.gz
+rainbow/lower.tar
+rainbow/lower.tar.gz
+rainbow/lu.tar.GZ
 rainbow/mh1
 rainbow/mh2
-rainbow/star.gz
-rainbow/star.tar
-rainbow/star.tar.gz
+rainbow/ul.TAR.gz
+rainbow/upper.GZ
+rainbow/upper.TAR
+rainbow/upper.TAR.GZ
diff --git a/tests/bfs/color_no.out b/tests/bfs/color_no.out
new file mode 100644
index 0000000..67e1eee
--- /dev/null
+++ b/tests/bfs/color_no.out
@@ -0,0 +1,27 @@
+$'rainbow/\e[1m'
+$'rainbow/\e[1m/'$'\e[0m'
+rainbow
+rainbow/exec.sh
+rainbow/socket
+rainbow/broken
+rainbow/chardev_link
+rainbow/link.txt
+rainbow/file.dat
+rainbow/file.txt
+rainbow/lower.gz
+rainbow/lower.tar
+rainbow/lower.tar.gz
+rainbow/lu.tar.GZ
+rainbow/mh1
+rainbow/mh2
+rainbow/ul.TAR.gz
+rainbow/upper.GZ
+rainbow/upper.TAR
+rainbow/upper.TAR.GZ
+rainbow/sticky_ow
+rainbow/sgid
+rainbow/pipe
+rainbow/ow
+rainbow/sugid
+rainbow/suid
+rainbow/sticky
diff --git a/tests/bfs/color_no.sh b/tests/bfs/color_no.sh
new file mode 100644
index 0000000..b7527cb
--- /dev/null
+++ b/tests/bfs/color_no.sh
@@ -0,0 +1 @@
+LS_COLORS="no=01;92:" bfs_diff rainbow -color
diff --git a/tests/bfs/color_no_stat.out b/tests/bfs/color_no_stat.out
index 1fc5324..e3031b2 100644
--- a/tests/bfs/color_no_stat.out
+++ b/tests/bfs/color_no_stat.out
@@ -1,7 +1,6 @@
+$'rainbow/\e[1m'
+$'rainbow/\e[1m/'$'\e[0m'
 rainbow
-rainbow/ow
-rainbow/sticky
-rainbow/sticky_ow
 rainbow/socket
 rainbow/broken
 rainbow/chardev_link
@@ -10,11 +9,19 @@
 rainbow/pipe
 rainbow/exec.sh
 rainbow/file.dat
+rainbow/lower.gz
+rainbow/lower.tar
+rainbow/lower.tar.gz
+rainbow/lu.tar.GZ
 rainbow/mh1
 rainbow/mh2
 rainbow/sgid
-rainbow/star.gz
-rainbow/star.tar
-rainbow/star.tar.gz
 rainbow/sugid
 rainbow/suid
+rainbow/ul.TAR.gz
+rainbow/upper.GZ
+rainbow/upper.TAR
+rainbow/upper.TAR.GZ
+rainbow/ow
+rainbow/sticky
+rainbow/sticky_ow
diff --git a/tests/bfs/color_nul.out b/tests/bfs/color_nul.out
index c328f82..8ccd9a7 100644
--- a/tests/bfs/color_nul.out
+++ b/tests/bfs/color_nul.out
diff --git a/tests/bfs/color_nul.sh b/tests/bfs/color_nul.sh
index 4979569..cb662d6 100644
--- a/tests/bfs/color_nul.sh
+++ b/tests/bfs/color_nul.sh
@@ -1,2 +1,3 @@
-LS_COLORS="ec=\33[m\0:" invoke_bfs rainbow -color -maxdepth 0 >"$OUT"
+LS_COLORS="ec=\33[\0m:*.gz=\0\61;31:" invoke_bfs rainbow -color | tr '\0' '0' >"$OUT"
+sort_output
 diff_output
diff --git a/tests/bfs/color_or.out b/tests/bfs/color_or.out
index 9e1fe5c..0bd2570 100644
--- a/tests/bfs/color_or.out
+++ b/tests/bfs/color_or.out
@@ -1,3 +1,5 @@
+$'rainbow/\e[1m'
+$'rainbow/\e[1m/'$'\e[0m'
 rainbow
 rainbow/exec.sh
 rainbow/socket
@@ -13,8 +15,13 @@
 rainbow/sticky
 rainbow/file.dat
 rainbow/file.txt
+rainbow/lower.gz
+rainbow/lower.tar
+rainbow/lower.tar.gz
+rainbow/lu.tar.GZ
 rainbow/mh1
 rainbow/mh2
-rainbow/star.gz
-rainbow/star.tar
-rainbow/star.tar.gz
+rainbow/ul.TAR.gz
+rainbow/upper.GZ
+rainbow/upper.TAR
+rainbow/upper.TAR.GZ
diff --git a/tests/bfs/color_or0_mi.out b/tests/bfs/color_or0_mi.out
index 77fc8a8..a439814 100644
--- a/tests/bfs/color_or0_mi.out
+++ b/tests/bfs/color_or0_mi.out
@@ -1,3 +1,5 @@
+$'rainbow/\e[1m'
+$'rainbow/\e[1m/'$'\e[0m'
 rainbow
 rainbow/exec.sh
 rainbow/socket
@@ -13,8 +15,13 @@
 rainbow/sticky
 rainbow/file.dat
 rainbow/file.txt
+rainbow/lower.gz
+rainbow/lower.tar
+rainbow/lower.tar.gz
+rainbow/lu.tar.GZ
 rainbow/mh1
 rainbow/mh2
-rainbow/star.gz
-rainbow/star.tar
-rainbow/star.tar.gz
+rainbow/ul.TAR.gz
+rainbow/upper.GZ
+rainbow/upper.TAR
+rainbow/upper.TAR.GZ
diff --git a/tests/bfs/color_or0_mi0.out b/tests/bfs/color_or0_mi0.out
index 77fc8a8..a439814 100644
--- a/tests/bfs/color_or0_mi0.out
+++ b/tests/bfs/color_or0_mi0.out
@@ -1,3 +1,5 @@
+$'rainbow/\e[1m'
+$'rainbow/\e[1m/'$'\e[0m'
 rainbow
 rainbow/exec.sh
 rainbow/socket
@@ -13,8 +15,13 @@
 rainbow/sticky
 rainbow/file.dat
 rainbow/file.txt
+rainbow/lower.gz
+rainbow/lower.tar
+rainbow/lower.tar.gz
+rainbow/lu.tar.GZ
 rainbow/mh1
 rainbow/mh2
-rainbow/star.gz
-rainbow/star.tar
-rainbow/star.tar.gz
+rainbow/ul.TAR.gz
+rainbow/upper.GZ
+rainbow/upper.TAR
+rainbow/upper.TAR.GZ
diff --git a/tests/bfs/color_or_mi.out b/tests/bfs/color_or_mi.out
index 5667f56..fb67e58 100644
--- a/tests/bfs/color_or_mi.out
+++ b/tests/bfs/color_or_mi.out
@@ -1,3 +1,5 @@
+$'rainbow/\e[1m'
+$'rainbow/\e[1m/'$'\e[0m'
 rainbow
 rainbow/broken
 rainbow/exec.sh
@@ -13,8 +15,13 @@
 rainbow/sticky
 rainbow/file.dat
 rainbow/file.txt
+rainbow/lower.gz
+rainbow/lower.tar
+rainbow/lower.tar.gz
+rainbow/lu.tar.GZ
 rainbow/mh1
 rainbow/mh2
-rainbow/star.gz
-rainbow/star.tar
-rainbow/star.tar.gz
+rainbow/ul.TAR.gz
+rainbow/upper.GZ
+rainbow/upper.TAR
+rainbow/upper.TAR.GZ
diff --git a/tests/bfs/color_or_mi0.out b/tests/bfs/color_or_mi0.out
index 5667f56..fb67e58 100644
--- a/tests/bfs/color_or_mi0.out
+++ b/tests/bfs/color_or_mi0.out
@@ -1,3 +1,5 @@
+$'rainbow/\e[1m'
+$'rainbow/\e[1m/'$'\e[0m'
 rainbow
 rainbow/broken
 rainbow/exec.sh
@@ -13,8 +15,13 @@
 rainbow/sticky
 rainbow/file.dat
 rainbow/file.txt
+rainbow/lower.gz
+rainbow/lower.tar
+rainbow/lower.tar.gz
+rainbow/lu.tar.GZ
 rainbow/mh1
 rainbow/mh2
-rainbow/star.gz
-rainbow/star.tar
-rainbow/star.tar.gz
+rainbow/ul.TAR.gz
+rainbow/upper.GZ
+rainbow/upper.TAR
+rainbow/upper.TAR.GZ
diff --git a/tests/bfs/color_rs_lc_rc_ec.out b/tests/bfs/color_rs_lc_rc_ec.out
index d39bbe7..077ef8d 100644
--- a/tests/bfs/color_rs_lc_rc_ec.out
+++ b/tests/bfs/color_rs_lc_rc_ec.out
@@ -1,3 +1,5 @@
+LC01;34RC$'rainbow/\e[1m'EC
+LC01;34RC$'rainbow/\e[1m/'EC$'\e[0m'
 LC01;34RCrainbow/ECLC01;32RCexec.shEC
 LC01;34RCrainbow/ECLC01;35RCsocketEC
 LC01;34RCrainbow/ECLC01;36RCbrokenEC
@@ -12,9 +14,14 @@ LC01;34RCrainbow/ECLC37;41RCsuidEC
 LC01;34RCrainbow/ECLC37;44RCstickyEC
 LC01;34RCrainbow/ECfile.dat
 LC01;34RCrainbow/ECfile.txt
+LC01;34RCrainbow/EClower.gz
+LC01;34RCrainbow/EClower.tar
+LC01;34RCrainbow/EClower.tar.gz
+LC01;34RCrainbow/EClu.tar.GZ
 LC01;34RCrainbow/ECmh1
 LC01;34RCrainbow/ECmh2
-LC01;34RCrainbow/ECstar.gz
-LC01;34RCrainbow/ECstar.tar
-LC01;34RCrainbow/ECstar.tar.gz
+LC01;34RCrainbow/ECul.TAR.gz
+LC01;34RCrainbow/ECupper.GZ
+LC01;34RCrainbow/ECupper.TAR
+LC01;34RCrainbow/ECupper.TAR.GZ
 LC01;34RCrainbowEC
diff --git a/tests/bfs/color_st0_tw0_ow.out b/tests/bfs/color_st0_tw0_ow.out
index 9a47ef2..a82762b 100644
--- a/tests/bfs/color_st0_tw0_ow.out
+++ b/tests/bfs/color_st0_tw0_ow.out
@@ -1,6 +1,7 @@
+$'rainbow/\e[1m'
+$'rainbow/\e[1m/'$'\e[0m'
 rainbow
 rainbow/exec.sh
-rainbow/sticky
 rainbow/socket
 rainbow/broken
 rainbow/chardev_link
@@ -13,8 +14,14 @@
 rainbow/suid
 rainbow/file.dat
 rainbow/file.txt
+rainbow/lower.gz
+rainbow/lower.tar
+rainbow/lower.tar.gz
+rainbow/lu.tar.GZ
 rainbow/mh1
 rainbow/mh2
-rainbow/star.gz
-rainbow/star.tar
-rainbow/star.tar.gz
+rainbow/ul.TAR.gz
+rainbow/upper.GZ
+rainbow/upper.TAR
+rainbow/upper.TAR.GZ
+rainbow/sticky
diff --git a/tests/bfs/color_st0_tw0_ow0.out b/tests/bfs/color_st0_tw0_ow0.out
index 2b86fe4..041f1d4 100644
--- a/tests/bfs/color_st0_tw0_ow0.out
+++ b/tests/bfs/color_st0_tw0_ow0.out
@@ -1,8 +1,7 @@
+$'rainbow/\e[1m'
+$'rainbow/\e[1m/'$'\e[0m'
 rainbow
 rainbow/exec.sh
-rainbow/ow
-rainbow/sticky
-rainbow/sticky_ow
 rainbow/socket
 rainbow/broken
 rainbow/chardev_link
@@ -13,8 +12,16 @@
 rainbow/suid
 rainbow/file.dat
 rainbow/file.txt
+rainbow/lower.gz
+rainbow/lower.tar
+rainbow/lower.tar.gz
+rainbow/lu.tar.GZ
 rainbow/mh1
 rainbow/mh2
-rainbow/star.gz
-rainbow/star.tar
-rainbow/star.tar.gz
+rainbow/ul.TAR.gz
+rainbow/upper.GZ
+rainbow/upper.TAR
+rainbow/upper.TAR.GZ
+rainbow/ow
+rainbow/sticky
+rainbow/sticky_ow
diff --git a/tests/bfs/color_st0_tw_ow.out b/tests/bfs/color_st0_tw_ow.out
index 42549a1..4dcb2f2 100644
--- a/tests/bfs/color_st0_tw_ow.out
+++ b/tests/bfs/color_st0_tw_ow.out
@@ -1,6 +1,7 @@
+$'rainbow/\e[1m'
+$'rainbow/\e[1m/'$'\e[0m'
 rainbow
 rainbow/exec.sh
-rainbow/sticky
 rainbow/socket
 rainbow/broken
 rainbow/chardev_link
@@ -13,8 +14,14 @@
 rainbow/sticky_ow
 rainbow/file.dat
 rainbow/file.txt
+rainbow/lower.gz
+rainbow/lower.tar
+rainbow/lower.tar.gz
+rainbow/lu.tar.GZ
 rainbow/mh1
 rainbow/mh2
-rainbow/star.gz
-rainbow/star.tar
-rainbow/star.tar.gz
+rainbow/ul.TAR.gz
+rainbow/upper.GZ
+rainbow/upper.TAR
+rainbow/upper.TAR.GZ
+rainbow/sticky
diff --git a/tests/bfs/color_st0_tw_ow0.out b/tests/bfs/color_st0_tw_ow0.out
index 535b8ae..954ce9c 100644
--- a/tests/bfs/color_st0_tw_ow0.out
+++ b/tests/bfs/color_st0_tw_ow0.out
@@ -1,7 +1,7 @@
+$'rainbow/\e[1m'
+$'rainbow/\e[1m/'$'\e[0m'
 rainbow
 rainbow/exec.sh
-rainbow/ow
-rainbow/sticky
 rainbow/socket
 rainbow/broken
 rainbow/chardev_link
@@ -13,8 +13,15 @@
 rainbow/sticky_ow
 rainbow/file.dat
 rainbow/file.txt
+rainbow/lower.gz
+rainbow/lower.tar
+rainbow/lower.tar.gz
+rainbow/lu.tar.GZ
 rainbow/mh1
 rainbow/mh2
-rainbow/star.gz
-rainbow/star.tar
-rainbow/star.tar.gz
+rainbow/ul.TAR.gz
+rainbow/upper.GZ
+rainbow/upper.TAR
+rainbow/upper.TAR.GZ
+rainbow/ow
+rainbow/sticky
diff --git a/tests/bfs/color_st_tw0_ow.out b/tests/bfs/color_st_tw0_ow.out
index c9a86f4..a6e9a16 100644
--- a/tests/bfs/color_st_tw0_ow.out
+++ b/tests/bfs/color_st_tw0_ow.out
@@ -1,3 +1,5 @@
+$'rainbow/\e[1m'
+$'rainbow/\e[1m/'$'\e[0m'
 rainbow
 rainbow/exec.sh
 rainbow/socket
@@ -13,8 +15,13 @@
 rainbow/sticky
 rainbow/file.dat
 rainbow/file.txt
+rainbow/lower.gz
+rainbow/lower.tar
+rainbow/lower.tar.gz
+rainbow/lu.tar.GZ
 rainbow/mh1
 rainbow/mh2
-rainbow/star.gz
-rainbow/star.tar
-rainbow/star.tar.gz
+rainbow/ul.TAR.gz
+rainbow/upper.GZ
+rainbow/upper.TAR
+rainbow/upper.TAR.GZ
diff --git a/tests/bfs/color_st_tw0_ow0.out b/tests/bfs/color_st_tw0_ow0.out
index 2d94f3a..756dafb 100644
--- a/tests/bfs/color_st_tw0_ow0.out
+++ b/tests/bfs/color_st_tw0_ow0.out
@@ -1,6 +1,7 @@
+$'rainbow/\e[1m'
+$'rainbow/\e[1m/'$'\e[0m'
 rainbow
 rainbow/exec.sh
-rainbow/ow
 rainbow/socket
 rainbow/broken
 rainbow/chardev_link
@@ -13,8 +14,14 @@
 rainbow/sticky_ow
 rainbow/file.dat
 rainbow/file.txt
+rainbow/lower.gz
+rainbow/lower.tar
+rainbow/lower.tar.gz
+rainbow/lu.tar.GZ
 rainbow/mh1
 rainbow/mh2
-rainbow/star.gz
-rainbow/star.tar
-rainbow/star.tar.gz
+rainbow/ul.TAR.gz
+rainbow/upper.GZ
+rainbow/upper.TAR
+rainbow/upper.TAR.GZ
+rainbow/ow
diff --git a/tests/bfs/color_st_tw_ow0.out b/tests/bfs/color_st_tw_ow0.out
index 317ef90..6e4a260 100644
--- a/tests/bfs/color_st_tw_ow0.out
+++ b/tests/bfs/color_st_tw_ow0.out
@@ -1,6 +1,7 @@
+$'rainbow/\e[1m'
+$'rainbow/\e[1m/'$'\e[0m'
 rainbow
 rainbow/exec.sh
-rainbow/ow
 rainbow/socket
 rainbow/broken
 rainbow/chardev_link
@@ -13,8 +14,14 @@
 rainbow/sticky_ow
 rainbow/file.dat
 rainbow/file.txt
+rainbow/lower.gz
+rainbow/lower.tar
+rainbow/lower.tar.gz
+rainbow/lu.tar.GZ
 rainbow/mh1
 rainbow/mh2
-rainbow/star.gz
-rainbow/star.tar
-rainbow/star.tar.gz
+rainbow/ul.TAR.gz
+rainbow/upper.GZ
+rainbow/upper.TAR
+rainbow/upper.TAR.GZ
+rainbow/ow
diff --git a/tests/bfs/color_star.sh b/tests/bfs/color_star.sh
index 3ada4fd..6d5312e 100644
--- a/tests/bfs/color_star.sh
+++ b/tests/bfs/color_star.sh
@@ -1,2 +1,2 @@
 # Regression test: don't segfault on LS_COLORS="*"
-LS_COLORS="*" bfs_diff rainbow -color
+! LS_COLORS="*" invoke_bfs rainbow -color
diff --git a/tests/bfs/color_su0_sg.out b/tests/bfs/color_su0_sg.out
index 8b8c8b8..d13b6b6 100644
--- a/tests/bfs/color_su0_sg.out
+++ b/tests/bfs/color_su0_sg.out
@@ -1,3 +1,5 @@
+$'rainbow/\e[1m'
+$'rainbow/\e[1m/'$'\e[0m'
 rainbow
 rainbow/exec.sh
 rainbow/socket
@@ -12,9 +14,14 @@
 rainbow/sticky
 rainbow/file.dat
 rainbow/file.txt
+rainbow/lower.gz
+rainbow/lower.tar
+rainbow/lower.tar.gz
+rainbow/lu.tar.GZ
 rainbow/mh1
 rainbow/mh2
-rainbow/star.gz
-rainbow/star.tar
-rainbow/star.tar.gz
 rainbow/suid
+rainbow/ul.TAR.gz
+rainbow/upper.GZ
+rainbow/upper.TAR
+rainbow/upper.TAR.GZ
diff --git a/tests/bfs/color_su0_sg0.out b/tests/bfs/color_su0_sg0.out
index 0cd5f9a..77fba58 100644
--- a/tests/bfs/color_su0_sg0.out
+++ b/tests/bfs/color_su0_sg0.out
@@ -1,3 +1,5 @@
+$'rainbow/\e[1m'
+$'rainbow/\e[1m/'$'\e[0m'
 rainbow
 rainbow/exec.sh
 rainbow/socket
@@ -10,11 +12,16 @@
 rainbow/sticky
 rainbow/file.dat
 rainbow/file.txt
+rainbow/lower.gz
+rainbow/lower.tar
+rainbow/lower.tar.gz
+rainbow/lu.tar.GZ
 rainbow/mh1
 rainbow/mh2
 rainbow/sgid
-rainbow/star.gz
-rainbow/star.tar
-rainbow/star.tar.gz
 rainbow/sugid
 rainbow/suid
+rainbow/ul.TAR.gz
+rainbow/upper.GZ
+rainbow/upper.TAR
+rainbow/upper.TAR.GZ
diff --git a/tests/bfs/color_su_sg0.out b/tests/bfs/color_su_sg0.out
index a9e8c5d..8fab046 100644
--- a/tests/bfs/color_su_sg0.out
+++ b/tests/bfs/color_su_sg0.out
@@ -1,3 +1,5 @@
+$'rainbow/\e[1m'
+$'rainbow/\e[1m/'$'\e[0m'
 rainbow
 rainbow/exec.sh
 rainbow/socket
@@ -12,9 +14,14 @@
 rainbow/sticky
 rainbow/file.dat
 rainbow/file.txt
+rainbow/lower.gz
+rainbow/lower.tar
+rainbow/lower.tar.gz
+rainbow/lu.tar.GZ
 rainbow/mh1
 rainbow/mh2
 rainbow/sgid
-rainbow/star.gz
-rainbow/star.tar
-rainbow/star.tar.gz
+rainbow/ul.TAR.gz
+rainbow/upper.GZ
+rainbow/upper.TAR
+rainbow/upper.TAR.GZ
diff --git a/tests/bfs/comma_incomplete.sh b/tests/bfs/comma_incomplete.sh
index 07cf505..bd60168 100644
--- a/tests/bfs/comma_incomplete.sh
+++ b/tests/bfs/comma_incomplete.sh
@@ -1 +1 @@
-fail invoke_bfs -print ,
+! invoke_bfs -print ,
diff --git a/tests/bfs/deep_strict.sh b/tests/bfs/deep_strict.sh
index e057310..22453c0 100644
--- a/tests/bfs/deep_strict.sh
+++ b/tests/bfs/deep_strict.sh
@@ -1,5 +1,3 @@
-closefrom 4
-
 # Not even enough fds to keep the root open
-ulimit -n 7
+ulimit -n $((NOPENFD + 4))
 bfs_diff deep -type f -exec bash -c 'echo "${1:0:6}/.../${1##*/} (${#1})"' bash {} \;
diff --git a/tests/bfs/exclude_exclude.sh b/tests/bfs/exclude_exclude.sh
index c687623..739342f 100644
--- a/tests/bfs/exclude_exclude.sh
+++ b/tests/bfs/exclude_exclude.sh
@@ -1 +1 @@
-fail invoke_bfs basic -exclude -exclude -name foo
+! invoke_bfs basic -exclude -exclude -name foo
diff --git a/tests/bfs/exclude_print.sh b/tests/bfs/exclude_print.sh
index 52ff0fd..dc89e1d 100644
--- a/tests/bfs/exclude_print.sh
+++ b/tests/bfs/exclude_print.sh
@@ -1 +1 @@
-fail invoke_bfs basic -exclude -print
+! invoke_bfs basic -exclude -print
diff --git a/tests/bfs/exec_flush_fprint.sh b/tests/bfs/exec_flush_fprint.sh
index bf6b62f..a862773 100644
--- a/tests/bfs/exec_flush_fprint.sh
+++ b/tests/bfs/exec_flush_fprint.sh
@@ -1,3 +1,2 @@
 # Even non-stdstreams should be flushed
-clean_scratch
-bfs_diff basic/a -fprint scratch/foo -exec cat scratch/foo \;
+bfs_diff basic/a -fprint "$OUT.f" -exec cat "$OUT.f" \;
diff --git a/tests/bfs/exec_flush_fprint_fail.sh b/tests/bfs/exec_flush_fprint_fail.sh
index 5da944a..cd38e41 100644
--- a/tests/bfs/exec_flush_fprint_fail.sh
+++ b/tests/bfs/exec_flush_fprint_fail.sh
@@ -1,2 +1,2 @@
-skip_unless test -e /dev/full
-fail invoke_bfs basic/a -fprint /dev/full -exec true \;
+test -e /dev/full || skip
+! invoke_bfs basic/a -fprint /dev/full -exec true \;
diff --git a/tests/bfs/execdir_plus.sh b/tests/bfs/execdir_plus.sh
index 9ae7764..6f24bdc 100644
--- a/tests/bfs/execdir_plus.sh
+++ b/tests/bfs/execdir_plus.sh
@@ -1,7 +1,4 @@
 tree=$(invoke_bfs -D tree 2>&1 -quit)
+[[ "$tree" == *"-S dfs"* ]] && skip
 
-if [[ "$tree" == *"-S dfs"* ]]; then
-    skip
-fi
-
-bfs_diff basic -execdir "$TESTS/sort-args.sh" {} +
+bfs_diff -j1 basic -execdir "$TESTS/sort-args.sh" {} +
diff --git a/tests/bfs/execdir_plus_nonexistent.sh b/tests/bfs/execdir_plus_nonexistent.sh
index 8436953..ed7ed56 100644
--- a/tests/bfs/execdir_plus_nonexistent.sh
+++ b/tests/bfs/execdir_plus_nonexistent.sh
@@ -1,5 +1,2 @@
-stderr=$(invoke_bfs basic -execdir "$TESTS/nonexistent" {} + 2>&1 >/dev/null)
-[ -n "$stderr" ] || return 1
-
-bfs_diff basic -execdir "$TESTS/nonexistent" {} + -print
-(($? == EX_BFS))
+bfs_diff basic -execdir "$TESTS/nonexistent" {} + -print 2>"$TEST/err" && fail
+test -s "$TEST/err"
diff --git a/tests/bfs/fprint_error_stderr.sh b/tests/bfs/fprint_error_stderr.sh
index 427808f..2cc4037 100644
--- a/tests/bfs/fprint_error_stderr.sh
+++ b/tests/bfs/fprint_error_stderr.sh
@@ -1,2 +1,2 @@
-skip_unless test -e /dev/full
-fail invoke_bfs basic -maxdepth 0 -fprint /dev/full 2>/dev/full
+test -e /dev/full || skip
+! invoke_bfs basic -maxdepth 0 -fprint /dev/full 2>/dev/full
diff --git a/tests/bfs/fprint_error_stdout.sh b/tests/bfs/fprint_error_stdout.sh
index fbdc1d0..42a7b36 100644
--- a/tests/bfs/fprint_error_stdout.sh
+++ b/tests/bfs/fprint_error_stdout.sh
@@ -1,2 +1,2 @@
-skip_unless test -e /dev/full
-fail invoke_bfs basic -maxdepth 0 -fprint /dev/full >/dev/full
+test -e /dev/full || skip
+! invoke_bfs basic -maxdepth 0 -fprint /dev/full >/dev/full
diff --git a/tests/bfs/help.sh b/tests/bfs/help.sh
index 5e5c684..5029c7e 100644
--- a/tests/bfs/help.sh
+++ b/tests/bfs/help.sh
@@ -1,6 +1,4 @@
-invoke_bfs -help | grep -E '\{...?\}' && return 1
-invoke_bfs -D help | grep -E '\{...?\}' && return 1
-invoke_bfs -S help | grep -E '\{...?\}' && return 1
-invoke_bfs -regextype help | grep -E '\{...?\}' && return 1
-
-return 0
+! invoke_bfs -help | grep -E '\{...?\}' || fail
+! invoke_bfs -D help | grep -E '\{...?\}' || fail
+! invoke_bfs -S help | grep -E '\{...?\}' || fail
+! invoke_bfs -regextype help | grep -E '\{...?\}' || fail
diff --git a/tests/bfs/high_byte.sh b/tests/bfs/high_byte.sh
index 222f24b..c76199f 100644
--- a/tests/bfs/high_byte.sh
+++ b/tests/bfs/high_byte.sh
@@ -1 +1 @@
-fail invoke_bfs -$'\xFF'
+! invoke_bfs -$'\xFF'
diff --git a/tests/bfs/j0.sh b/tests/bfs/j0.sh
new file mode 100644
index 0000000..97a7c5c
--- /dev/null
+++ b/tests/bfs/j0.sh
@@ -0,0 +1 @@
+! invoke_bfs -j0 basic
diff --git a/tests/bfs/j1.out b/tests/bfs/j1.out
new file mode 100644
index 0000000..a7ccfe4
--- /dev/null
+++ b/tests/bfs/j1.out
@@ -0,0 +1,19 @@
+basic
+basic/a
+basic/b
+basic/c
+basic/c/d
+basic/e
+basic/e/f
+basic/g
+basic/g/h
+basic/i
+basic/j
+basic/j/foo
+basic/k
+basic/k/foo
+basic/k/foo/bar
+basic/l
+basic/l/foo
+basic/l/foo/bar
+basic/l/foo/bar/baz
diff --git a/tests/bfs/j1.sh b/tests/bfs/j1.sh
new file mode 100644
index 0000000..972ac1b
--- /dev/null
+++ b/tests/bfs/j1.sh
@@ -0,0 +1 @@
+bfs_diff -j1 basic
diff --git a/tests/bfs/j64.out b/tests/bfs/j64.out
new file mode 100644
index 0000000..a7ccfe4
--- /dev/null
+++ b/tests/bfs/j64.out
@@ -0,0 +1,19 @@
+basic
+basic/a
+basic/b
+basic/c
+basic/c/d
+basic/e
+basic/e/f
+basic/g
+basic/g/h
+basic/i
+basic/j
+basic/j/foo
+basic/k
+basic/k/foo
+basic/k/foo/bar
+basic/l
+basic/l/foo
+basic/l/foo/bar
+basic/l/foo/bar/baz
diff --git a/tests/bfs/j64.sh b/tests/bfs/j64.sh
new file mode 100644
index 0000000..c56788f
--- /dev/null
+++ b/tests/bfs/j64.sh
@@ -0,0 +1 @@
+bfs_diff -j64 basic
diff --git a/tests/bfs/j_negative.sh b/tests/bfs/j_negative.sh
new file mode 100644
index 0000000..809c98c
--- /dev/null
+++ b/tests/bfs/j_negative.sh
@@ -0,0 +1 @@
+! invoke_bfs -j-1 basic
diff --git a/tests/bfs/limit.out b/tests/bfs/limit.out
new file mode 100644
index 0000000..ea94276
--- /dev/null
+++ b/tests/bfs/limit.out
@@ -0,0 +1,4 @@
+basic/a
+basic/b
+basic/c/d
+basic/e/f
diff --git a/tests/bfs/limit.sh b/tests/bfs/limit.sh
new file mode 100644
index 0000000..84b605f
--- /dev/null
+++ b/tests/bfs/limit.sh
@@ -0,0 +1 @@
+bfs_diff -s basic -type f -print -limit 4
diff --git a/tests/bfs/limit_0.sh b/tests/bfs/limit_0.sh
new file mode 100644
index 0000000..3ce26de
--- /dev/null
+++ b/tests/bfs/limit_0.sh
@@ -0,0 +1 @@
+! invoke_bfs basic -print -limit 0
diff --git a/tests/bfs/limit_implicit_print.sh b/tests/bfs/limit_implicit_print.sh
new file mode 100644
index 0000000..cdb059d
--- /dev/null
+++ b/tests/bfs/limit_implicit_print.sh
@@ -0,0 +1 @@
+! invoke_bfs basic -type f -limit 1
diff --git a/tests/bfs/limit_incomplete.sh b/tests/bfs/limit_incomplete.sh
new file mode 100644
index 0000000..2d1e842
--- /dev/null
+++ b/tests/bfs/limit_incomplete.sh
@@ -0,0 +1 @@
+! invoke_bfs basic -print -limit
diff --git a/tests/bfs/limit_one.sh b/tests/bfs/limit_one.sh
new file mode 100644
index 0000000..3f8181c
--- /dev/null
+++ b/tests/bfs/limit_one.sh
@@ -0,0 +1 @@
+! invoke_bfs basic -print -limit one
diff --git a/tests/bfs/links_empty.sh b/tests/bfs/links_empty.sh
index 34c7c25..42cf6e5 100644
--- a/tests/bfs/links_empty.sh
+++ b/tests/bfs/links_empty.sh
@@ -1 +1 @@
-fail invoke_bfs links -links ''
+! invoke_bfs links -links ''
diff --git a/tests/bfs/links_invalid.sh b/tests/bfs/links_invalid.sh
index ff69fa6..4d139c9 100644
--- a/tests/bfs/links_invalid.sh
+++ b/tests/bfs/links_invalid.sh
@@ -1 +1 @@
-fail invoke_bfs links -links ASDF
+! invoke_bfs links -links ASDF
diff --git a/tests/bfs/links_leading_space.sh b/tests/bfs/links_leading_space.sh
new file mode 100644
index 0000000..15957af
--- /dev/null
+++ b/tests/bfs/links_leading_space.sh
@@ -0,0 +1 @@
+! invoke_bfs links -links ' 1'
diff --git a/tests/bfs/links_negative.sh b/tests/bfs/links_negative.sh
index b5d9c58..e664b99 100644
--- a/tests/bfs/links_negative.sh
+++ b/tests/bfs/links_negative.sh
@@ -1 +1 @@
-fail invoke_bfs links -links +-1
+! invoke_bfs links -links +-1
diff --git a/tests/bfs/links_noarg.sh b/tests/bfs/links_noarg.sh
index 5dede5f..5c948dc 100644
--- a/tests/bfs/links_noarg.sh
+++ b/tests/bfs/links_noarg.sh
@@ -1 +1 @@
-fail invoke_bfs links -links
+! invoke_bfs links -links
diff --git a/tests/bfs/newerma_nonexistent.sh b/tests/bfs/newerma_nonexistent.sh
index 7f3695f..cdedb4a 100644
--- a/tests/bfs/newerma_nonexistent.sh
+++ b/tests/bfs/newerma_nonexistent.sh
@@ -1 +1 @@
-fail invoke_bfs times -newerma basic/nonexistent
+! invoke_bfs times -newerma basic/nonexistent
diff --git a/tests/bfs/newermq.sh b/tests/bfs/newermq.sh
index 2a22586..2f705dc 100644
--- a/tests/bfs/newermq.sh
+++ b/tests/bfs/newermq.sh
@@ -1 +1 @@
-fail invoke_bfs times -newermq times/a
+! invoke_bfs times -newermq times/a
diff --git a/tests/bfs/newermt_invalid.sh b/tests/bfs/newermt_invalid.sh
index 61d2485..98efece 100644
--- a/tests/bfs/newermt_invalid.sh
+++ b/tests/bfs/newermt_invalid.sh
@@ -1 +1 @@
-fail invoke_bfs times -newermt not_a_date_time
+! invoke_bfs times -newermt not_a_date_time
diff --git a/tests/bfs/newerqm.sh b/tests/bfs/newerqm.sh
index da84350..c0cff98 100644
--- a/tests/bfs/newerqm.sh
+++ b/tests/bfs/newerqm.sh
@@ -1 +1 @@
-fail invoke_bfs times -newerqm times/a
+! invoke_bfs times -newerqm times/a
diff --git a/tests/bfs/nocolor.out b/tests/bfs/nocolor.out
index b53fe03..d51d24d 100644
--- a/tests/bfs/nocolor.out
+++ b/tests/bfs/nocolor.out
@@ -1,20 +1,27 @@
 rainbow
+rainbow/
+rainbow//
 rainbow/broken
 rainbow/chardev_link
 rainbow/exec.sh
 rainbow/file.dat
 rainbow/file.txt
 rainbow/link.txt
+rainbow/lower.gz
+rainbow/lower.tar
+rainbow/lower.tar.gz
+rainbow/lu.tar.GZ
 rainbow/mh1
 rainbow/mh2
 rainbow/ow
 rainbow/pipe
 rainbow/sgid
 rainbow/socket
-rainbow/star.gz
-rainbow/star.tar
-rainbow/star.tar.gz
 rainbow/sticky
 rainbow/sticky_ow
 rainbow/sugid
 rainbow/suid
+rainbow/ul.TAR.gz
+rainbow/upper.GZ
+rainbow/upper.TAR
+rainbow/upper.TAR.GZ
diff --git a/tests/bfs/nocolor_env.out b/tests/bfs/nocolor_env.out
new file mode 100644
index 0000000..d51d24d
--- /dev/null
+++ b/tests/bfs/nocolor_env.out
@@ -0,0 +1,27 @@
+rainbow
+rainbow/
+rainbow//
+rainbow/broken
+rainbow/chardev_link
+rainbow/exec.sh
+rainbow/file.dat
+rainbow/file.txt
+rainbow/link.txt
+rainbow/lower.gz
+rainbow/lower.tar
+rainbow/lower.tar.gz
+rainbow/lu.tar.GZ
+rainbow/mh1
+rainbow/mh2
+rainbow/ow
+rainbow/pipe
+rainbow/sgid
+rainbow/socket
+rainbow/sticky
+rainbow/sticky_ow
+rainbow/sugid
+rainbow/suid
+rainbow/ul.TAR.gz
+rainbow/upper.GZ
+rainbow/upper.TAR
+rainbow/upper.TAR.GZ
diff --git a/tests/bfs/nocolor_env.sh b/tests/bfs/nocolor_env.sh
new file mode 100644
index 0000000..d1c2afb
--- /dev/null
+++ b/tests/bfs/nocolor_env.sh
@@ -0,0 +1,3 @@
+NO_COLOR=1 bfs_pty rainbow >"$OUT"
+sort_output
+diff_output
diff --git a/tests/bfs/nocolor_env_empty.out b/tests/bfs/nocolor_env_empty.out
new file mode 100644
index 0000000..a439814
--- /dev/null
+++ b/tests/bfs/nocolor_env_empty.out
@@ -0,0 +1,27 @@
+$'rainbow/\e[1m'
+$'rainbow/\e[1m/'$'\e[0m'
+rainbow
+rainbow/exec.sh
+rainbow/socket
+rainbow/broken
+rainbow/chardev_link
+rainbow/link.txt
+rainbow/sticky_ow
+rainbow/sgid
+rainbow/pipe
+rainbow/ow
+rainbow/sugid
+rainbow/suid
+rainbow/sticky
+rainbow/file.dat
+rainbow/file.txt
+rainbow/lower.gz
+rainbow/lower.tar
+rainbow/lower.tar.gz
+rainbow/lu.tar.GZ
+rainbow/mh1
+rainbow/mh2
+rainbow/ul.TAR.gz
+rainbow/upper.GZ
+rainbow/upper.TAR
+rainbow/upper.TAR.GZ
diff --git a/tests/bfs/nocolor_env_empty.sh b/tests/bfs/nocolor_env_empty.sh
new file mode 100644
index 0000000..1edfb1d
--- /dev/null
+++ b/tests/bfs/nocolor_env_empty.sh
@@ -0,0 +1,3 @@
+NO_COLOR= bfs_pty rainbow >"$OUT"
+sort_output
+diff_output
diff --git a/tests/bfs/or_incomplete.sh b/tests/bfs/or_incomplete.sh
index c941b95..4af31b6 100644
--- a/tests/bfs/or_incomplete.sh
+++ b/tests/bfs/or_incomplete.sh
@@ -1 +1 @@
-fail invoke_bfs -print -o
+! invoke_bfs -print -o
diff --git a/tests/bfs/perm_symbolic_double_comma.sh b/tests/bfs/perm_symbolic_double_comma.sh
index 66db0ac..48f9d4b 100644
--- a/tests/bfs/perm_symbolic_double_comma.sh
+++ b/tests/bfs/perm_symbolic_double_comma.sh
@@ -1 +1 @@
-fail invoke_bfs perms -perm a+r,,u+w
+! invoke_bfs perms -perm a+r,,u+w
diff --git a/tests/bfs/perm_symbolic_missing_action.sh b/tests/bfs/perm_symbolic_missing_action.sh
index 3b18721..28446ab 100644
--- a/tests/bfs/perm_symbolic_missing_action.sh
+++ b/tests/bfs/perm_symbolic_missing_action.sh
@@ -1 +1 @@
-fail invoke_bfs perms -perm a
+! invoke_bfs perms -perm a
diff --git a/tests/bfs/perm_symbolic_trailing_comma.sh b/tests/bfs/perm_symbolic_trailing_comma.sh
index c52ebe6..01bbc16 100644
--- a/tests/bfs/perm_symbolic_trailing_comma.sh
+++ b/tests/bfs/perm_symbolic_trailing_comma.sh
@@ -1 +1 @@
-fail invoke_bfs perms -perm a+r,
+! invoke_bfs perms -perm a+r,
diff --git a/tests/bfs/printf_color.out b/tests/bfs/printf_color.out
index d9cd1a4..77d21c3 100644
--- a/tests/bfs/printf_color.out
+++ b/tests/bfs/printf_color.out
@@ -1,5 +1,8 @@
-. . rainbow ./rainbow rainbow 
+. $'./rainbow/\e[1m' $'\e[0m' $'./rainbow/\e[1m/'$'\e[0m' $'rainbow/\e[1m/'$'\e[0m' 
+. . . .  
+. . rainbow ./rainbow rainbow 
 . ./rainbow exec.sh ./rainbow/exec.sh rainbow/exec.sh 
+. ./rainbow $'\e[1m' $'./rainbow/\e[1m' $'rainbow/\e[1m' 
 . ./rainbow socket ./rainbow/socket rainbow/socket 
 . ./rainbow broken ./rainbow/broken rainbow/broken nowhere
 . ./rainbow chardev_link ./rainbow/chardev_link rainbow/chardev_link /dev/null
@@ -13,8 +16,13 @@
 . ./rainbow sticky ./rainbow/sticky rainbow/sticky 
 . ./rainbow file.dat ./rainbow/file.dat rainbow/file.dat 
 . ./rainbow file.txt ./rainbow/file.txt rainbow/file.txt 
+. ./rainbow lower.gz ./rainbow/lower.gz rainbow/lower.gz 
+. ./rainbow lower.tar ./rainbow/lower.tar rainbow/lower.tar 
+. ./rainbow lower.tar.gz ./rainbow/lower.tar.gz rainbow/lower.tar.gz 
+. ./rainbow lu.tar.GZ ./rainbow/lu.tar.GZ rainbow/lu.tar.GZ 
 . ./rainbow mh1 ./rainbow/mh1 rainbow/mh1 
 . ./rainbow mh2 ./rainbow/mh2 rainbow/mh2 
-. ./rainbow star.gz ./rainbow/star.gz rainbow/star.gz 
-. ./rainbow star.tar ./rainbow/star.tar rainbow/star.tar 
-. ./rainbow star.tar.gz ./rainbow/star.tar.gz rainbow/star.tar.gz 
+. ./rainbow ul.TAR.gz ./rainbow/ul.TAR.gz rainbow/ul.TAR.gz 
+. ./rainbow upper.GZ ./rainbow/upper.GZ rainbow/upper.GZ 
+. ./rainbow upper.TAR ./rainbow/upper.TAR rainbow/upper.TAR 
+. ./rainbow upper.TAR.GZ ./rainbow/upper.TAR.GZ rainbow/upper.TAR.GZ 
diff --git a/tests/bfs/printf_color.sh b/tests/bfs/printf_color.sh
index 7bb38c2..3641ddb 100644
--- a/tests/bfs/printf_color.sh
+++ b/tests/bfs/printf_color.sh
@@ -1 +1 @@
-bfs_diff -color -path './rainbow*' -printf '%H %h %f %p %P %l\n'
+bfs_diff -color -exclude \( -depth 1 -not -name rainbow \) -printf '%H %h %f %p %P %l\n'
diff --git a/tests/bfs/printf_duplicate_flag.sh b/tests/bfs/printf_duplicate_flag.sh
index 77650d0..5ff29f1 100644
--- a/tests/bfs/printf_duplicate_flag.sh
+++ b/tests/bfs/printf_duplicate_flag.sh
@@ -1 +1 @@
-fail invoke_bfs basic -printf '%--p'
+! invoke_bfs basic -printf '%--p'
diff --git a/tests/bfs/printf_everything.sh b/tests/bfs/printf_everything.sh
index 5f20718..07d574a 100644
--- a/tests/bfs/printf_everything.sh
+++ b/tests/bfs/printf_everything.sh
@@ -1,14 +1,14 @@
 everything=(%{a,b,c,d,D,f,g,G,h,H,i,k,l,m,M,n,p,P,s,S,t,u,U,y,Y})
 
 # Check if we have fstypes
-if ! fail invoke_bfs basic -printf '%F' -quit >/dev/null; then
+if invoke_bfs basic -printf '%F' -quit >/dev/null; then
     everything+=(%F)
 fi
 
 everything+=(%{A,C,T}{%,+,@,a,A,b,B,c,C,d,D,e,F,g,G,h,H,I,j,k,l,m,M,n,p,r,R,s,S,t,T,u,U,V,w,W,x,X,y,Y,z,Z})
 
 # Check if we have birth times
-if ! fail invoke_bfs basic -printf '%w' -quit >/dev/null; then
+if invoke_bfs basic -printf '%w' -quit >/dev/null; then
     everything+=(%w %{B,W}{%,+,@,a,A,b,B,c,C,d,D,e,F,g,G,h,H,I,j,k,l,m,M,n,p,r,R,s,S,t,T,u,U,V,w,W,x,X,y,Y,z,Z})
 fi
 
diff --git a/tests/bfs/printf_incomplete_escape.sh b/tests/bfs/printf_incomplete_escape.sh
index 144add5..f560d28 100644
--- a/tests/bfs/printf_incomplete_escape.sh
+++ b/tests/bfs/printf_incomplete_escape.sh
@@ -1 +1 @@
-fail invoke_bfs basic -printf '\'
+! invoke_bfs basic -printf '\'
diff --git a/tests/bfs/printf_incomplete_format.sh b/tests/bfs/printf_incomplete_format.sh
index 347a0f4..92c6afc 100644
--- a/tests/bfs/printf_incomplete_format.sh
+++ b/tests/bfs/printf_incomplete_format.sh
@@ -1 +1 @@
-fail invoke_bfs basic -printf '%'
+! invoke_bfs basic -printf '%'
diff --git a/tests/bfs/printf_invalid_escape.sh b/tests/bfs/printf_invalid_escape.sh
index ce12233..4338f9b 100644
--- a/tests/bfs/printf_invalid_escape.sh
+++ b/tests/bfs/printf_invalid_escape.sh
@@ -1 +1 @@
-fail invoke_bfs basic -printf '\!'
+! invoke_bfs basic -printf '\!'
diff --git a/tests/bfs/printf_invalid_format.sh b/tests/bfs/printf_invalid_format.sh
index 1717615..59d63a7 100644
--- a/tests/bfs/printf_invalid_format.sh
+++ b/tests/bfs/printf_invalid_format.sh
@@ -1 +1 @@
-fail invoke_bfs basic -printf '%!'
+! invoke_bfs basic -printf '%!'
diff --git a/tests/bfs/printf_must_be_numeric.sh b/tests/bfs/printf_must_be_numeric.sh
index eabb3d6..7c7c3fa 100644
--- a/tests/bfs/printf_must_be_numeric.sh
+++ b/tests/bfs/printf_must_be_numeric.sh
@@ -1 +1 @@
-fail invoke_bfs basic -printf '%+p'
+! invoke_bfs basic -printf '%+p'
diff --git a/tests/bfs/status.sh b/tests/bfs/status.sh
new file mode 100644
index 0000000..83e12d3
--- /dev/null
+++ b/tests/bfs/status.sh
@@ -0,0 +1 @@
+bfs_pty basic -status -print -depth 0 -exec stty cols 123 rows 14 \; >"$OUT"
diff --git a/tests/bfs/stderr_fails_loudly.sh b/tests/bfs/stderr_fails_loudly.sh
index d8b3861..8572d5a 100644
--- a/tests/bfs/stderr_fails_loudly.sh
+++ b/tests/bfs/stderr_fails_loudly.sh
@@ -1,2 +1,2 @@
-skip_unless test -e /dev/full
-fail invoke_bfs -D all basic -false -fprint /dev/full 2>/dev/full
+test -e /dev/full || skip
+! invoke_bfs -D all basic -false -fprint /dev/full 2>/dev/full
diff --git a/tests/bfs/stderr_fails_silently.sh b/tests/bfs/stderr_fails_silently.sh
index 731cb02..a37393d 100644
--- a/tests/bfs/stderr_fails_silently.sh
+++ b/tests/bfs/stderr_fails_silently.sh
@@ -1,2 +1,2 @@
-skip_unless test -e /dev/full
+test -e /dev/full || skip
 bfs_diff -D all basic 2>/dev/full
diff --git a/tests/bfs/unexpected_operator.sh b/tests/bfs/unexpected_operator.sh
index b3658f6..2eb0e71 100644
--- a/tests/bfs/unexpected_operator.sh
+++ b/tests/bfs/unexpected_operator.sh
@@ -1 +1 @@
-fail invoke_bfs \! -o -print
+! invoke_bfs \! -o -print
diff --git a/tests/bfs/warn_O9.out b/tests/bfs/warn_O9.out
new file mode 100644
index 0000000..336a6e8
--- /dev/null
+++ b/tests/bfs/warn_O9.out
@@ -0,0 +1,19 @@
+.
+./a
+./b
+./c
+./c/d
+./e
+./e/f
+./g
+./g/h
+./i
+./j
+./j/foo
+./k
+./k/foo
+./k/foo/bar
+./l
+./l/foo
+./l/foo/bar
+./l/foo/bar/baz
diff --git a/tests/bfs/warn_O9.sh b/tests/bfs/warn_O9.sh
new file mode 100644
index 0000000..821789f
--- /dev/null
+++ b/tests/bfs/warn_O9.sh
@@ -0,0 +1,3 @@
+# Regression test: don't crash when warning if -O9 is the last argument
+cd basic
+bfs_diff -warn -O9
diff --git a/tests/bfs/warn_xdev_mount.out b/tests/bfs/warn_xdev_mount.out
new file mode 100644
index 0000000..a7ccfe4
--- /dev/null
+++ b/tests/bfs/warn_xdev_mount.out
@@ -0,0 +1,19 @@
+basic
+basic/a
+basic/b
+basic/c
+basic/c/d
+basic/e
+basic/e/f
+basic/g
+basic/g/h
+basic/i
+basic/j
+basic/j/foo
+basic/k
+basic/k/foo
+basic/k/foo/bar
+basic/l
+basic/l/foo
+basic/l/foo/bar
+basic/l/foo/bar/baz
diff --git a/tests/bfs/warn_xdev_mount.sh b/tests/bfs/warn_xdev_mount.sh
new file mode 100644
index 0000000..5d395f6
--- /dev/null
+++ b/tests/bfs/warn_xdev_mount.sh
@@ -0,0 +1,2 @@
+# Regression test: don't crash if -mount is the last option
+bfs_diff basic -warn -xdev -mount
diff --git a/tests/bfs/xtype_depth.sh b/tests/bfs/xtype_depth.sh
index cd478af..02c8173 100644
--- a/tests/bfs/xtype_depth.sh
+++ b/tests/bfs/xtype_depth.sh
@@ -1,2 +1,2 @@
 # Make sure -xtype is considered side-effecting for facts_when_impure
-fail invoke_bfs loops -xtype l -depth 100
+! invoke_bfs loops -xtype l -depth 100
diff --git a/tests/bfstd.c b/tests/bfstd.c
new file mode 100644
index 0000000..07b68b0
--- /dev/null
+++ b/tests/bfstd.c
@@ -0,0 +1,93 @@
+// Copyright © Tavian Barnes <tavianator@tavianator.com>
+// SPDX-License-Identifier: 0BSD
+
+#include "prelude.h"
+#include "tests.h"
+#include "bfstd.h"
+#include "diag.h"
+#include <errno.h>
+#include <langinfo.h>
+#include <stdlib.h>
+#include <string.h>
+
+/** Check the result of xdirname()/xbasename(). */
+static bool check_base_dir(const char *path, const char *dir, const char *base) {
+	bool ret = true;
+
+	char *xdir = xdirname(path);
+	bfs_verify(xdir, "xdirname(): %s", xstrerror(errno));
+	ret &= bfs_check(strcmp(xdir, dir) == 0, "xdirname('%s') == '%s' (!= '%s')", path, xdir, dir);
+	free(xdir);
+
+	char *xbase = xbasename(path);
+	bfs_verify(xbase, "xbasename(): %s", xstrerror(errno));
+	ret &= bfs_check(strcmp(xbase, base) == 0, "xbasename('%s') == '%s' (!= '%s')", path, xbase, base);
+	free(xbase);
+
+	return ret;
+}
+
+/** Check the result of wordesc(). */
+static bool check_wordesc(const char *str, const char *exp, enum wesc_flags flags) {
+	char buf[256];
+	char *end = buf + sizeof(buf);
+	char *esc = wordesc(buf, end, str, flags);
+
+	return bfs_check(esc != end)
+		&& bfs_check(strcmp(buf, exp) == 0, "wordesc('%s') == '%s' (!= '%s')", str, buf, exp);
+}
+
+bool check_bfstd(void) {
+	bool ret = true;
+
+	ret &= bfs_check(asciilen("") == 0);
+	ret &= bfs_check(asciilen("@") == 1);
+	ret &= bfs_check(asciilen("@@") == 2);
+	ret &= bfs_check(asciilen("\xFF@") == 0);
+	ret &= bfs_check(asciilen("@\xFF") == 1);
+	ret &= bfs_check(asciilen("@@@@@@@@") == 8);
+	ret &= bfs_check(asciilen("@@@@@@@@@@@@@@@@") == 16);
+	ret &= bfs_check(asciilen("@@@@@@@@@@@@@@@@@@@@@@@@") == 24);
+	ret &= bfs_check(asciilen("@@@@@@@@@@@@@@a\xFF@@@@@@@") == 15);
+	ret &= bfs_check(asciilen("@@@@@@@@@@@@@@@@\xFF@@@@@@@") == 16);
+	ret &= bfs_check(asciilen("@@@@@@@@@@@@@@@@a\xFF@@@@@@") == 17);
+	ret &= bfs_check(asciilen("@@@@@@@\xFF@@@@@@a\xFF@@@@@@@") == 7);
+	ret &= bfs_check(asciilen("@@@@@@@@\xFF@@@@@a\xFF@@@@@@@") == 8);
+	ret &= bfs_check(asciilen("@@@@@@@@@\xFF@@@@a\xFF@@@@@@@") == 9);
+
+	// From man 3p basename
+	ret &= check_base_dir("usr", ".", "usr");
+	ret &= check_base_dir("usr/", ".", "usr");
+	ret &= check_base_dir("", ".", ".");
+	ret &= check_base_dir("/", "/", "/");
+	// check_base_dir("//", "/" or "//", "/" or "//");
+	ret &= check_base_dir("///", "/", "/");
+	ret &= check_base_dir("/usr/", "/", "usr");
+	ret &= check_base_dir("/usr/lib", "/usr", "lib");
+	ret &= check_base_dir("//usr//lib//", "//usr", "lib");
+	ret &= check_base_dir("/home//dwc//test", "/home//dwc", "test");
+
+	ret &= check_wordesc("", "\"\"", WESC_SHELL);
+	ret &= check_wordesc("word", "word", WESC_SHELL);
+	ret &= check_wordesc("two words", "\"two words\"", WESC_SHELL);
+	ret &= check_wordesc("word's", "\"word's\"", WESC_SHELL);
+	ret &= check_wordesc("\"word\"", "'\"word\"'", WESC_SHELL);
+	ret &= check_wordesc("\"word's\"", "'\"word'\\''s\"'", WESC_SHELL);
+	ret &= check_wordesc("\033[1mbold's\033[0m", "$'\\e[1mbold\\'s\\e[0m'", WESC_SHELL | WESC_TTY);
+	ret &= check_wordesc("\x7F", "$'\\x7F'", WESC_SHELL | WESC_TTY);
+	ret &= check_wordesc("~user", "\"~user\"", WESC_SHELL);
+
+	const char *charmap = nl_langinfo(CODESET);
+	if (strcmp(charmap, "UTF-8") == 0) {
+		ret &= check_wordesc("\xF0", "$'\\xF0'", WESC_SHELL | WESC_TTY);
+		ret &= check_wordesc("\xF0\x9F", "$'\\xF0\\x9F'", WESC_SHELL | WESC_TTY);
+		ret &= check_wordesc("\xF0\x9F\x98", "$'\\xF0\\x9F\\x98'", WESC_SHELL | WESC_TTY);
+		ret &= check_wordesc("\xF0\x9F\x98\x80", "\xF0\x9F\x98\x80", WESC_SHELL | WESC_TTY);
+		ret &= check_wordesc("\xCB\x9Cuser", "\xCB\x9Cuser", WESC_SHELL);
+	}
+
+	ret &= bfs_check(xstrwidth("Hello world") == 11);
+	ret &= bfs_check(xstrwidth("Hello\1world") == 10);
+
+	return ret;
+}
diff --git a/tests/bit.c b/tests/bit.c
new file mode 100644
index 0000000..674d1b2
--- /dev/null
+++ b/tests/bit.c
@@ -0,0 +1,141 @@
+// Copyright © Tavian Barnes <tavianator@tavianator.com>
+// SPDX-License-Identifier: 0BSD
+
+#include "prelude.h"
+#include "tests.h"
+#include "bit.h"
+#include "diag.h"
+#include <limits.h>
+#include <stdint.h>
+#include <string.h>
+
+bfs_static_assert(UMAX_WIDTH(0x1) == 1);
+bfs_static_assert(UMAX_WIDTH(0x3) == 2);
+bfs_static_assert(UMAX_WIDTH(0x7) == 3);
+bfs_static_assert(UMAX_WIDTH(0xF) == 4);
+bfs_static_assert(UMAX_WIDTH(0xFF) == 8);
+bfs_static_assert(UMAX_WIDTH(0xFFF) == 12);
+bfs_static_assert(UMAX_WIDTH(0xFFFF) == 16);
+
+#define UWIDTH_MAX(n) (2 * ((UINTMAX_C(1) << ((n) - 1)) - 1) + 1)
+#define IWIDTH_MAX(n) UWIDTH_MAX((n) - 1)
+#define IWIDTH_MIN(n) (-(intmax_t)IWIDTH_MAX(n) - 1)
+
+bfs_static_assert(UCHAR_MAX == UWIDTH_MAX(UCHAR_WIDTH));
+bfs_static_assert(SCHAR_MIN == IWIDTH_MIN(SCHAR_WIDTH));
+bfs_static_assert(SCHAR_MAX == IWIDTH_MAX(SCHAR_WIDTH));
+
+bfs_static_assert(USHRT_MAX == UWIDTH_MAX(USHRT_WIDTH));
+bfs_static_assert(SHRT_MIN == IWIDTH_MIN(SHRT_WIDTH));
+bfs_static_assert(SHRT_MAX == IWIDTH_MAX(SHRT_WIDTH));
+
+bfs_static_assert(UINT_MAX == UWIDTH_MAX(UINT_WIDTH));
+bfs_static_assert(INT_MIN == IWIDTH_MIN(INT_WIDTH));
+bfs_static_assert(INT_MAX == IWIDTH_MAX(INT_WIDTH));
+
+bfs_static_assert(ULONG_MAX == UWIDTH_MAX(ULONG_WIDTH));
+bfs_static_assert(LONG_MIN == IWIDTH_MIN(LONG_WIDTH));
+bfs_static_assert(LONG_MAX == IWIDTH_MAX(LONG_WIDTH));
+
+bfs_static_assert(ULLONG_MAX == UWIDTH_MAX(ULLONG_WIDTH));
+bfs_static_assert(LLONG_MIN == IWIDTH_MIN(LLONG_WIDTH));
+bfs_static_assert(LLONG_MAX == IWIDTH_MAX(LLONG_WIDTH));
+
+bfs_static_assert(SIZE_MAX == UWIDTH_MAX(SIZE_WIDTH));
+bfs_static_assert(PTRDIFF_MIN == IWIDTH_MIN(PTRDIFF_WIDTH));
+bfs_static_assert(PTRDIFF_MAX == IWIDTH_MAX(PTRDIFF_WIDTH));
+
+bfs_static_assert(UINTPTR_MAX == UWIDTH_MAX(UINTPTR_WIDTH));
+bfs_static_assert(INTPTR_MIN == IWIDTH_MIN(INTPTR_WIDTH));
+bfs_static_assert(INTPTR_MAX == IWIDTH_MAX(INTPTR_WIDTH));
+
+bfs_static_assert(UINTMAX_MAX == UWIDTH_MAX(UINTMAX_WIDTH));
+bfs_static_assert(INTMAX_MIN == IWIDTH_MIN(INTMAX_WIDTH));
+bfs_static_assert(INTMAX_MAX == IWIDTH_MAX(INTMAX_WIDTH));
+
+#define check_eq(a, b) \
+	bfs_check((a) == (b), "(0x%jX) %s != %s (0x%jX)", (uintmax_t)(a), #a, #b, (uintmax_t)(b))
+
+bool check_bit(void) {
+	bool ret = true;
+
+	const char *str = "\x1\x2\x3\x4";
+	uint32_t word;
+	memcpy(&word, str, sizeof(word));
+
+#if ENDIAN_NATIVE == ENDIAN_LITTLE
+	ret &= check_eq(word, 0x04030201);
+#elif ENDIAN_NATIVE == ENDIAN_BIG
+	ret &= check_eq(word, 0x01020304);
+#else
+#  warning "Skipping byte order tests on mixed/unknown-endian machine"
+#endif
+
+	ret &= check_eq(bswap((uint8_t)0x12), 0x12);
+	ret &= check_eq(bswap((uint16_t)0x1234), 0x3412);
+	ret &= check_eq(bswap((uint32_t)0x12345678), 0x78563412);
+	ret &= check_eq(bswap((uint64_t)0x1234567812345678), 0x7856341278563412);
+
+	ret &= check_eq(count_ones(0x0), 0);
+	ret &= check_eq(count_ones(0x1), 1);
+	ret &= check_eq(count_ones(0x2), 1);
+	ret &= check_eq(count_ones(0x3), 2);
+	ret &= check_eq(count_ones(0x137F), 10);
+
+	ret &= check_eq(count_zeros(0), INT_WIDTH);
+	ret &= check_eq(count_zeros(0L), LONG_WIDTH);
+	ret &= check_eq(count_zeros(0LL), LLONG_WIDTH);
+	ret &= check_eq(count_zeros((uint8_t)0), 8);
+	ret &= check_eq(count_zeros((uint16_t)0), 16);
+	ret &= check_eq(count_zeros((uint32_t)0), 32);
+	ret &= check_eq(count_zeros((uint64_t)0), 64);
+
+	ret &= check_eq(rotate_left((uint8_t)0xA1, 4), 0x1A);
+	ret &= check_eq(rotate_left((uint16_t)0x1234, 12), 0x4123);
+	ret &= check_eq(rotate_left((uint32_t)0x12345678, 20), 0x67812345);
+	ret &= check_eq(rotate_left((uint32_t)0x12345678, 0), 0x12345678);
+
+	ret &= check_eq(rotate_right((uint8_t)0xA1, 4), 0x1A);
+	ret &= check_eq(rotate_right((uint16_t)0x1234, 12), 0x2341);
+	ret &= check_eq(rotate_right((uint32_t)0x12345678, 20), 0x45678123);
+	ret &= check_eq(rotate_right((uint32_t)0x12345678, 0), 0x12345678);
+
+	for (int i = 0; i < 16; ++i) {
+		uint16_t n = (uint16_t)1 << i;
+		for (int j = i; j < 16; ++j) {
+			uint16_t m = (uint16_t)1 << j;
+			uint16_t nm = n | m;
+			ret &= check_eq(count_ones(nm), 1 + (n != m));
+			ret &= check_eq(count_zeros(nm), 15 - (n != m));
+			ret &= check_eq(leading_zeros(nm), 15 - j);
+			ret &= check_eq(trailing_zeros(nm), i);
+			ret &= check_eq(first_leading_one(nm), j + 1);
+			ret &= check_eq(first_trailing_one(nm), i + 1);
+			ret &= check_eq(bit_width(nm), j + 1);
+			ret &= check_eq(bit_floor(nm), m);
+			if (n == m) {
+				ret &= check_eq(bit_ceil(nm), m);
+				ret &= bfs_check(has_single_bit(nm));
+			} else {
+				if (j < 15) {
+					ret &= check_eq(bit_ceil(nm), (m << 1));
+				}
+				ret &= bfs_check(!has_single_bit(nm));
+			}
+		}
+	}
+
+	ret &= check_eq(leading_zeros((uint16_t)0), 16);
+	ret &= check_eq(trailing_zeros((uint16_t)0), 16);
+	ret &= check_eq(first_leading_one(0), 0);
+	ret &= check_eq(first_trailing_one(0), 0);
+	ret &= check_eq(bit_width(0), 0);
+	ret &= check_eq(bit_floor(0), 0);
+	ret &= check_eq(bit_ceil(0), 1);
+
+	ret &= bfs_check(!has_single_bit(0));
+	ret &= bfs_check(!has_single_bit(UINT32_MAX));
+	ret &= bfs_check(has_single_bit((uint32_t)1 << (UINT_WIDTH - 1)));
+
+	return ret;
+}
diff --git a/tests/bsd/L_acl.out b/tests/bsd/L_acl.out
index 1dae00a..dd89800 100644
--- a/tests/bsd/L_acl.out
+++ b/tests/bsd/L_acl.out
@@ -1,2 +1,2 @@
-scratch/acl
-scratch/link
+./acl
+./link
diff --git a/tests/bsd/L_acl.sh b/tests/bsd/L_acl.sh
index cf573e4..a3fcbc8 100644
--- a/tests/bsd/L_acl.sh
+++ b/tests/bsd/L_acl.sh
@@ -1,9 +1,9 @@
-clean_scratch
+cd "$TEST"
 
-skip_unless invoke_bfs scratch -quit -acl
+invoke_bfs . -quit -acl || skip
 
-"$XTOUCH" scratch/{normal,acl}
-skip_unless set_acl scratch/acl
-ln -s acl scratch/link
+"$XTOUCH" normal acl
+set_acl acl || skip
+ln -s acl link
 
-bfs_diff -L scratch -acl
+bfs_diff -L . -acl
diff --git a/tests/bsd/L_xattr.out b/tests/bsd/L_xattr.out
index 12fac95..21eb50f 100644
--- a/tests/bsd/L_xattr.out
+++ b/tests/bsd/L_xattr.out
@@ -1,3 +1,3 @@
-scratch/link
-scratch/xattr
-scratch/xattr_2
+./link
+./xattr
+./xattr_2
diff --git a/tests/bsd/L_xattr.sh b/tests/bsd/L_xattr.sh
index 7c27e0d..f8b56d8 100644
--- a/tests/bsd/L_xattr.sh
+++ b/tests/bsd/L_xattr.sh
@@ -1,3 +1,3 @@
-skip_unless invoke_bfs scratch -quit -xattr
-skip_unless make_xattrs
-bfs_diff -L scratch -xattr
+invoke_bfs . -quit -xattr || skip
+make_xattrs || skip
+bfs_diff -L . -xattr
diff --git a/tests/bsd/L_xattrname.out b/tests/bsd/L_xattrname.out
index 4dc4836..9e4c172 100644
--- a/tests/bsd/L_xattrname.out
+++ b/tests/bsd/L_xattrname.out
@@ -1,2 +1,2 @@
-scratch/link
-scratch/xattr
+./link
+./xattr
diff --git a/tests/bsd/L_xattrname.sh b/tests/bsd/L_xattrname.sh
index 39d6a77..8108d57 100644
--- a/tests/bsd/L_xattrname.sh
+++ b/tests/bsd/L_xattrname.sh
@@ -1,11 +1,11 @@
-skip_unless invoke_bfs scratch -quit -xattr
-skip_unless make_xattrs
+invoke_bfs . -quit -xattr || skip
+make_xattrs || skip
 
 case "$UNAME" in
     Darwin|FreeBSD)
-        bfs_diff -L scratch -xattrname bfs_test
+        bfs_diff -L . -xattrname bfs_test
         ;;
     *)
-        bfs_diff -L scratch -xattrname security.bfs_test
+        bfs_diff -L . -xattrname security.bfs_test
         ;;
 esac
diff --git a/tests/bsd/X.sh b/tests/bsd/X.sh
index 03d9eee..54000cf 100644
--- a/tests/bsd/X.sh
+++ b/tests/bsd/X.sh
@@ -1,2 +1 @@
-bfs_diff -X weirdnames
-[ $? -eq $EX_BFS ]
+! bfs_diff -X weirdnames
diff --git a/tests/bsd/acl.out b/tests/bsd/acl.out
index ddf8446..92e2f67 100644
--- a/tests/bsd/acl.out
+++ b/tests/bsd/acl.out
@@ -1 +1 @@
-scratch/acl
+./acl
diff --git a/tests/bsd/acl.sh b/tests/bsd/acl.sh
index 1665684..a13c75f 100644
--- a/tests/bsd/acl.sh
+++ b/tests/bsd/acl.sh
@@ -1,9 +1,9 @@
-clean_scratch
+cd "$TEST"
 
-skip_unless invoke_bfs scratch -quit -acl
+invoke_bfs . -quit -acl || skip
 
-"$XTOUCH" scratch/{normal,acl}
-skip_unless set_acl scratch/acl
-ln -s acl scratch/link
+"$XTOUCH" normal acl
+set_acl acl || skip
+ln -s acl link
 
-bfs_diff scratch -acl
+bfs_diff . -acl
diff --git a/tests/bsd/exit.sh b/tests/bsd/exit.sh
index 524a75f..248349c 100644
--- a/tests/bsd/exit.sh
+++ b/tests/bsd/exit.sh
@@ -1,11 +1,5 @@
-invoke_bfs basic -name foo -exit 42
-if [ $? -ne 42 ]; then
-    return 1
-fi
+check_exit 42 invoke_bfs basic -name foo -exit 42
 
-invoke_bfs basic -name qux -exit 42
-if [ $? -ne 0 ]; then
-    return 1
-fi
+check_exit 0 invoke_bfs basic -name qux -exit 42
 
 bfs_diff basic/g -print -name g -exit
diff --git a/tests/bsd/f_incomplete.sh b/tests/bsd/f_incomplete.sh
index acb63af..0dfb19f 100644
--- a/tests/bsd/f_incomplete.sh
+++ b/tests/bsd/f_incomplete.sh
@@ -1,2 +1 @@
-fail invoke_bfs -f
-
+! invoke_bfs -f
diff --git a/tests/bsd/flags.out b/tests/bsd/flags.out
index 11998ed..3216ff5 100644
--- a/tests/bsd/flags.out
+++ b/tests/bsd/flags.out
@@ -1 +1 @@
-scratch/bar
+./bar
diff --git a/tests/bsd/flags.sh b/tests/bsd/flags.sh
index ffb1cc2..eb9bc22 100644
--- a/tests/bsd/flags.sh
+++ b/tests/bsd/flags.sh
@@ -1,8 +1,8 @@
-skip_unless invoke_bfs scratch -quit -flags offline
+invoke_bfs . -quit -flags offline || skip
 
-clean_scratch
+cd "$TEST"
 
-"$XTOUCH" scratch/{foo,bar}
-skip_unless chflags offline scratch/bar
+"$XTOUCH" foo bar
+chflags offline bar || skip
 
-bfs_diff scratch -flags -offline,nohidden
+bfs_diff . -flags -offline,nohidden
diff --git a/tests/bsd/mtime_bad_unit.sh b/tests/bsd/mtime_bad_unit.sh
index 3921f80..6e2caf1 100644
--- a/tests/bsd/mtime_bad_unit.sh
+++ b/tests/bsd/mtime_bad_unit.sh
@@ -1 +1 @@
-fail invoke_bfs times -mtime +1q
+! invoke_bfs times -mtime +1q
diff --git a/tests/bsd/mtime_missing_unit.sh b/tests/bsd/mtime_missing_unit.sh
index 3ac4c97..f6b1f93 100644
--- a/tests/bsd/mtime_missing_unit.sh
+++ b/tests/bsd/mtime_missing_unit.sh
@@ -1 +1 @@
-fail invoke_bfs times -mtime +1w2
+! invoke_bfs times -mtime +1w2
diff --git a/tests/bsd/rm.out b/tests/bsd/rm.out
index fb188b9..9c558e3 100644
--- a/tests/bsd/rm.out
+++ b/tests/bsd/rm.out
@@ -1 +1 @@
-scratch
+.
diff --git a/tests/bsd/rm.sh b/tests/bsd/rm.sh
index 9ee2b0a..595d514 100644
--- a/tests/bsd/rm.sh
+++ b/tests/bsd/rm.sh
@@ -1,6 +1,4 @@
-clean_scratch
-"$XTOUCH" -p scratch/foo/bar/baz
-
-(cd scratch && invoke_bfs . -rm)
-
-bfs_diff scratch
+cd "$TEST"
+"$XTOUCH" -p foo/bar/baz
+invoke_bfs . -rm
+bfs_diff .
diff --git a/tests/bsd/s_quit.out b/tests/bsd/s_quit.out
new file mode 100644
index 0000000..5ea492b
--- /dev/null
+++ b/tests/bsd/s_quit.out
@@ -0,0 +1 @@
+basic/j/foo
diff --git a/tests/bsd/s_quit.sh b/tests/bsd/s_quit.sh
new file mode 100644
index 0000000..6bd55ab
--- /dev/null
+++ b/tests/bsd/s_quit.sh
@@ -0,0 +1,4 @@
+# Regression test: bfs -S ids -s -name foo -quit would not actually quit,
+# ending up in a confused state and erroring/crashing
+
+bfs_diff -s basic -name foo -print -quit
diff --git a/tests/bsd/sparse.out b/tests/bsd/sparse.out
new file mode 100644
index 0000000..52dcf49
--- /dev/null
+++ b/tests/bsd/sparse.out
@@ -0,0 +1 @@
+mnt/sparse
diff --git a/tests/bsd/sparse.sh b/tests/bsd/sparse.sh
new file mode 100644
index 0000000..7fcdeed
--- /dev/null
+++ b/tests/bsd/sparse.sh
@@ -0,0 +1,12 @@
+test "$UNAME" = "Linux" || skip
+
+cd "$TEST"
+mkdir mnt
+
+bfs_sudo mount -t tmpfs tmpfs mnt || skip
+defer bfs_sudo umount mnt
+
+truncate -s 1M mnt/sparse
+dd if=/dev/zero of=mnt/dense bs=1M count=1
+
+bfs_diff mnt -type f -sparse
diff --git a/tests/bsd/type_w.out b/tests/bsd/type_w.out
new file mode 100644
index 0000000..a20a4f3
--- /dev/null
+++ b/tests/bsd/type_w.out
@@ -0,0 +1,34 @@
+1: -rw-r--r-- mnt/lower/bar
+1: -rw-r--r-- mnt/lower/baz
+1: -rw-r--r-- mnt/lower/foo
+1: -rw-r--r-- mnt/upper/baz/qux
+1: -rw-r--r-- mnt/upper/foo
+1: drwxr-xr-x mnt/lower
+1: drwxr-xr-x mnt/upper
+1: drwxr-xr-x mnt/upper/baz
+2: w--------- mnt/upper/bar
+3: -rw-r--r-- mnt/lower/bar
+3: -rw-r--r-- mnt/lower/baz
+3: -rw-r--r-- mnt/lower/foo
+3: -rw-r--r-- mnt/upper/baz/qux
+3: -rw-r--r-- mnt/upper/foo
+3: drwxr-xr-x mnt/lower
+3: drwxr-xr-x mnt/upper
+3: drwxr-xr-x mnt/upper/baz
+3: w--------- mnt/upper/bar
+4: -rw-r--r-- mnt/lower/bar
+4: -rw-r--r-- mnt/lower/baz
+4: -rw-r--r-- mnt/lower/foo
+4: -rw-r--r-- mnt/upper/baz/qux
+4: drwxr-xr-x mnt/lower
+4: drwxr-xr-x mnt/upper
+4: drwxr-xr-x mnt/upper/baz
+5: w--------- mnt/upper/bar
+6: -rw-r--r-- mnt/lower/bar
+6: -rw-r--r-- mnt/lower/baz
+6: -rw-r--r-- mnt/lower/foo
+6: -rw-r--r-- mnt/upper/baz/qux
+6: drwxr-xr-x mnt/lower
+6: drwxr-xr-x mnt/upper
+6: drwxr-xr-x mnt/upper/baz
+6: w--------- mnt/upper/bar
diff --git a/tests/bsd/type_w.sh b/tests/bsd/type_w.sh
new file mode 100644
index 0000000..3aa50d5
--- /dev/null
+++ b/tests/bsd/type_w.sh
@@ -0,0 +1,56 @@
+# Only ffs supports whiteouts on FreeBSD
+command -v mdconfig &>/dev/null || skip
+command -v newfs &>/dev/null || skip
+
+cd "$TEST"
+
+# Create a ramdisk
+if command -v truncate &>/dev/null; then
+    truncate -s1M img
+else
+    dd if=/dev/zero of=img bs=1k count=1k
+fi
+md=$(bfs_sudo mdconfig img) || skip
+defer bfs_sudo mdconfig -du "$md"
+
+# Make an ffs filesystem
+bfs_sudo newfs -n "/dev/$md" >&2 || skip
+mkdir mnt
+
+# Mount it
+bfs_sudo mount "/dev/$md" mnt || skip
+defer bfs_sudo umount mnt
+
+# Make it owned by us
+bfs_sudo chown "$(id -u):$(id -g)" mnt
+"$XTOUCH" -p mnt/{lower/{foo,bar,baz},upper/{bar,baz/qux}}
+
+# Mount a union filesystem within it
+bfs_sudo mount -t unionfs -o below mnt/{lower,upper}
+defer bfs_sudo umount mnt/upper
+
+# Create a whiteout
+rm mnt/upper/bar
+
+# FreeBSD find doesn't have -printf, so munge -ls output
+munge_ls() {
+    sed -En 's|.*([-drwx]{10}).*(mnt/.*)|'"$1"': \1 \2|p'
+}
+
+# Do a few tests in one
+{
+    # Normally, we shouldn't see the whiteouts
+    invoke_bfs mnt -ls | munge_ls 1
+    # -type w adds whiteouts to the output
+    invoke_bfs mnt -type w -ls | munge_ls 2
+    # So this is not the same as test 1
+    invoke_bfs mnt \( -type w -or -not -type w \) -ls | munge_ls 3
+    # Unmount the unionfs
+    pop_defer
+    # Now repeat the same tests
+    invoke_bfs mnt -ls | munge_ls 4
+    invoke_bfs mnt -type w -ls | munge_ls 5
+    invoke_bfs mnt \( -type w -or -not -type w \) -ls | munge_ls 6
+} >"$OUT"
+sort_output
+diff_output
diff --git a/tests/bsd/xattr.out b/tests/bsd/xattr.out
index 109e7c9..0afed35 100644
--- a/tests/bsd/xattr.out
+++ b/tests/bsd/xattr.out
@@ -1,3 +1,3 @@
-scratch/xattr
-scratch/xattr_2
-scratch/xattr_link
+./xattr
+./xattr_2
+./xattr_link
diff --git a/tests/bsd/xattr.sh b/tests/bsd/xattr.sh
index 727c220..68f729a 100644
--- a/tests/bsd/xattr.sh
+++ b/tests/bsd/xattr.sh
@@ -1,3 +1,3 @@
-skip_unless invoke_bfs scratch -quit -xattr
-skip_unless make_xattrs
-bfs_diff scratch -xattr
+invoke_bfs . -quit -xattr || skip
+make_xattrs || skip
+bfs_diff . -xattr
diff --git a/tests/bsd/xattrname.out b/tests/bsd/xattrname.out
index 0285ac1..ef732bd 100644
--- a/tests/bsd/xattrname.out
+++ b/tests/bsd/xattrname.out
@@ -1,2 +1,2 @@
-scratch/xattr
-scratch/xattr_link
+./xattr
+./xattr_link
diff --git a/tests/bsd/xattrname.sh b/tests/bsd/xattrname.sh
index 6a0fe7e..38b111a 100644
--- a/tests/bsd/xattrname.sh
+++ b/tests/bsd/xattrname.sh
@@ -1,11 +1,11 @@
-skip_unless invoke_bfs scratch -quit -xattr
-skip_unless make_xattrs
+invoke_bfs . -quit -xattr || skip
+make_xattrs || skip
 
 case "$UNAME" in
     Darwin|FreeBSD)
-        bfs_diff scratch -xattrname bfs_test
+        bfs_diff . -xattrname bfs_test
         ;;
     *)
-        bfs_diff scratch -xattrname security.bfs_test
+        bfs_diff . -xattrname security.bfs_test
         ;;
 esac
diff --git a/tests/color.sh b/tests/color.sh
new file mode 100644
index 0000000..805d2b8
--- /dev/null
+++ b/tests/color.sh
@@ -0,0 +1,37 @@
+#!/hint/bash
+
+# Copyright © Tavian Barnes <tavianator@tavianator.com>
+# SPDX-License-Identifier: 0BSD
+
+## Colored output
+
+# Common escape sequences
+BLD=$'\e[01m'
+RED=$'\e[01;31m'
+GRN=$'\e[01;32m'
+YLW=$'\e[01;33m'
+BLU=$'\e[01;34m'
+MAG=$'\e[01;35m'
+CYN=$'\e[01;36m'
+RST=$'\e[0m'
+
+# Check if we should color output to the given fd
+color_fd() {
+    [ -z "${NO_COLOR:-}" ] && [ -t "$1" ]
+}
+
+# Cache the color status for std{out,err}
+color_fd 1 && COLOR_STDOUT=1 || COLOR_STDOUT=0
+color_fd 2 && COLOR_STDERR=1 || COLOR_STDERR=0
+
+# Save this in case the tests unset PATH
+SED=$(command -v sed)
+
+# Filter out escape sequences if necessary
+color() {
+    if color_fd 1; then
+        "$@"
+    else
+        "$@" | "$SED" $'s/\e\\[[^m]*m//g'
+    fi
+}
diff --git a/tests/common/L_ilname.sh b/tests/common/L_ilname.sh
index cfb15a8..e0495ed 100644
--- a/tests/common/L_ilname.sh
+++ b/tests/common/L_ilname.sh
@@ -1,2 +1,2 @@
-skip_unless invoke_bfs -quit -ilname PATTERN
+invoke_bfs -quit -ilname PATTERN || skip
 bfs_diff -L links -ilname '[AQ]'
diff --git a/tests/common/L_ls.sh b/tests/common/L_ls.sh
index ced16c6..7ee2b44 100644
--- a/tests/common/L_ls.sh
+++ b/tests/common/L_ls.sh
@@ -1,2 +1 @@
-clean_scratch
-invoke_bfs -L rainbow -ls >scratch/L_ls.out
+invoke_bfs -L rainbow -ls >"$OUT"
diff --git a/tests/common/L_mount.out b/tests/common/L_mount.out
index 2e80082..788579d 100644
--- a/tests/common/L_mount.out
+++ b/tests/common/L_mount.out
@@ -1,5 +1,5 @@
-scratch
-scratch/foo
-scratch/foo/bar
-scratch/foo/qux
-scratch/mnt
+.
+./foo
+./foo/bar
+./foo/qux
+./mnt
diff --git a/tests/common/L_mount.sh b/tests/common/L_mount.sh
index dad7e00..fd8042a 100644
--- a/tests/common/L_mount.sh
+++ b/tests/common/L_mount.sh
@@ -1,15 +1,13 @@
-skip_unless test "$SUDO"
-skip_if test "$UNAME" = "Darwin"
+test "$UNAME" = "Darwin" && skip
 
-clean_scratch
-mkdir scratch/{foo,mnt}
-sudo mount -t tmpfs tmpfs scratch/mnt
-ln -s ../mnt scratch/foo/bar
-"$XTOUCH" scratch/mnt/baz
-ln -s ../mnt/baz scratch/foo/qux
+cd "$TEST"
+mkdir foo mnt
 
-bfs_diff -L scratch -mount
-ret=$?
+bfs_sudo mount -t tmpfs tmpfs mnt || skip
+defer bfs_sudo umount mnt
 
-sudo umount scratch/mnt
-return $ret
+ln -s ../mnt foo/bar
+"$XTOUCH" mnt/baz
+ln -s ../mnt/baz foo/qux
+
+bfs_diff -L . -mount
diff --git a/tests/common/delete.out b/tests/common/delete.out
index fb188b9..9c558e3 100644
--- a/tests/common/delete.out
+++ b/tests/common/delete.out
@@ -1 +1 @@
-scratch
+.
diff --git a/tests/common/delete.sh b/tests/common/delete.sh
index 89cf2a2..638f307 100644
--- a/tests/common/delete.sh
+++ b/tests/common/delete.sh
@@ -1,7 +1,4 @@
-clean_scratch
-"$XTOUCH" -p scratch/foo/bar/baz
-
-# Don't try to delete '.'
-(cd scratch && invoke_bfs . -delete)
-
-bfs_diff scratch
+cd "$TEST"
+"$XTOUCH" -p foo/bar/baz
+invoke_bfs . -delete
+bfs_diff .
diff --git a/tests/common/delete_error.out b/tests/common/delete_error.out
new file mode 100644
index 0000000..b6b6505
--- /dev/null
+++ b/tests/common/delete_error.out
@@ -0,0 +1,8 @@
+.
+.
+./baz
+./baz
+./baz/qux
+./baz/qux
+./foo
+./foo/bar
diff --git a/tests/common/delete_error.sh b/tests/common/delete_error.sh
new file mode 100644
index 0000000..e6327f3
--- /dev/null
+++ b/tests/common/delete_error.sh
@@ -0,0 +1,9 @@
+cd "$TEST"
+
+"$XTOUCH" -p foo/bar baz/qux
+chmod -w foo
+defer chmod +w foo
+
+! invoke_bfs . -print -delete -print >"$OUT" || fail
+sort_output
+diff_output
diff --git a/tests/common/delete_many.out b/tests/common/delete_many.out
index fb188b9..9c558e3 100644
--- a/tests/common/delete_many.out
+++ b/tests/common/delete_many.out
@@ -1 +1 @@
-scratch
+.
diff --git a/tests/common/delete_many.sh b/tests/common/delete_many.sh
index 6274319..48fe4c2 100644
--- a/tests/common/delete_many.sh
+++ b/tests/common/delete_many.sh
@@ -1,8 +1,8 @@
 # Test for https://github.com/tavianator/bfs/issues/67
 
-clean_scratch
-mkdir scratch/foo
-"$XTOUCH" scratch/foo/{1..256}
+cd "$TEST"
+mkdir foo
+"$XTOUCH" foo/{1..256}
 
-invoke_bfs scratch/foo -delete
-bfs_diff scratch
+invoke_bfs foo -delete
+bfs_diff .
diff --git a/tests/gnu/empty.out b/tests/common/empty.out
index a0f4b76..a0f4b76 100644
--- a/tests/gnu/empty.out
+++ b/tests/common/empty.out
diff --git a/tests/gnu/empty.sh b/tests/common/empty.sh
index 95ee988..95ee988 100644
--- a/tests/gnu/empty.sh
+++ b/tests/common/empty.sh
diff --git a/tests/common/empty_error.out b/tests/common/empty_error.out
new file mode 100644
index 0000000..da45e23
--- /dev/null
+++ b/tests/common/empty_error.out
@@ -0,0 +1,3 @@
+./bar
+./baz
+./qux
diff --git a/tests/common/empty_error.sh b/tests/common/empty_error.sh
new file mode 100644
index 0000000..7c8049c
--- /dev/null
+++ b/tests/common/empty_error.sh
@@ -0,0 +1,7 @@
+cd "$TEST"
+
+"$XTOUCH" -p foo/ bar/ baz qux
+chmod -r foo baz
+defer chmod +r foo baz
+
+! bfs_diff . -empty
diff --git a/tests/common/empty_special.out b/tests/common/empty_special.out
new file mode 100644
index 0000000..fa35478
--- /dev/null
+++ b/tests/common/empty_special.out
@@ -0,0 +1,20 @@
+rainbow//
+rainbow/exec.sh
+rainbow/file.dat
+rainbow/file.txt
+rainbow/lower.gz
+rainbow/lower.tar
+rainbow/lower.tar.gz
+rainbow/lu.tar.GZ
+rainbow/mh1
+rainbow/mh2
+rainbow/ow
+rainbow/sgid
+rainbow/sticky
+rainbow/sticky_ow
+rainbow/sugid
+rainbow/suid
+rainbow/ul.TAR.gz
+rainbow/upper.GZ
+rainbow/upper.TAR
+rainbow/upper.TAR.GZ
diff --git a/tests/gnu/empty_special.sh b/tests/common/empty_special.sh
index 31e9d2e..31e9d2e 100644
--- a/tests/gnu/empty_special.sh
+++ b/tests/common/empty_special.sh
diff --git a/tests/common/execdir_nonexistent.sh b/tests/common/execdir_nonexistent.sh
index 5d116e5..0ec013c 100644
--- a/tests/common/execdir_nonexistent.sh
+++ b/tests/common/execdir_nonexistent.sh
@@ -1,5 +1,2 @@
-stderr=$(invoke_bfs basic -execdir "$TESTS/nonexistent" {} \; 2>&1 >/dev/null)
-[ -n "$stderr" ] || return 1
-
-bfs_diff basic -print -execdir "$TESTS/nonexistent" {} \; -print
-(($? == EX_BFS))
+bfs_diff basic -print -execdir "$TESTS/nonexistent" {} \; -print 2>"$TEST/err" && fail
+test -s "$TEST/err"
diff --git a/tests/common/execdir_ulimit.out b/tests/common/execdir_ulimit.out
index 7f53982..bf52c09 100644
--- a/tests/common/execdir_ulimit.out
+++ b/tests/common/execdir_ulimit.out
@@ -1,3 +1,4 @@
+./.
 ./0
 ./1
 ./2
@@ -30,7 +31,6 @@
 ./q
 ./r
 ./s
-./scratch
 ./t
 ./u
 ./v
diff --git a/tests/common/execdir_ulimit.sh b/tests/common/execdir_ulimit.sh
index 8bd9edd..122c282 100644
--- a/tests/common/execdir_ulimit.sh
+++ b/tests/common/execdir_ulimit.sh
@@ -1,7 +1,6 @@
-clean_scratch
-mkdir -p scratch/a/b/c/d/e/f/g/h/i/j/k/l/m/n/o/p/q/r/s/t/u/v/w/x/y/z
-mkdir -p scratch/a/b/c/d/e/f/g/h/i/j/k/l/m/0/1/2/3/4/5/6/7/8/9/A/B/C
+cd "$TEST"
+mkdir -p a/b/c/d/e/f/g/h/i/j/k/l/m/n/o/p/q/r/s/t/u/v/w/x/y/z
+mkdir -p a/b/c/d/e/f/g/h/i/j/k/l/m/0/1/2/3/4/5/6/7/8/9/A/B/C
 
-closefrom 4
-ulimit -n 13
-bfs_diff scratch -execdir echo {} \;
+ulimit -n $((NOPENFD + 10))
+bfs_diff . -execdir echo {} \;
diff --git a/tests/common/ilname.sh b/tests/common/ilname.sh
index 7ab0793..fc7e9e4 100644
--- a/tests/common/ilname.sh
+++ b/tests/common/ilname.sh
@@ -1,2 +1,2 @@
-skip_unless invoke_bfs -quit -ilname PATTERN
+invoke_bfs -quit -ilname PATTERN || skip
 bfs_diff links -ilname '[AQ]'
diff --git a/tests/common/iname.sh b/tests/common/iname.sh
index 8fcc443..c25a646 100644
--- a/tests/common/iname.sh
+++ b/tests/common/iname.sh
@@ -1,2 +1,2 @@
-skip_unless invoke_bfs -quit -iname PATTERN
+invoke_bfs -quit -iname PATTERN || skip
 bfs_diff basic -iname '*F*'
diff --git a/tests/common/inum_bind_mount.out b/tests/common/inum_bind_mount.out
index a520de3..ede8749 100644
--- a/tests/common/inum_bind_mount.out
+++ b/tests/common/inum_bind_mount.out
@@ -1,2 +1,2 @@
-scratch/bar
-scratch/foo
+./bar
+./foo
diff --git a/tests/common/inum_bind_mount.sh b/tests/common/inum_bind_mount.sh
index e35ed4e..892713e 100644
--- a/tests/common/inum_bind_mount.sh
+++ b/tests/common/inum_bind_mount.sh
@@ -1,12 +1,9 @@
-skip_unless test "$SUDO"
-skip_unless test "$UNAME" = "Linux"
+test "$UNAME" = "Linux" || skip
 
-clean_scratch
-"$XTOUCH" scratch/{foo,bar}
-sudo mount --bind scratch/{foo,bar}
+cd "$TEST"
+"$XTOUCH" foo bar baz
 
-bfs_diff scratch -inum "$(inum scratch/bar)"
-ret=$?
+bfs_sudo mount --bind foo bar || skip
+defer bfs_sudo umount bar
 
-sudo umount scratch/bar
-return $ret
+bfs_diff . -inum "$(inum bar)"
diff --git a/tests/common/inum_mount.out b/tests/common/inum_mount.out
index 99c7511..99fa01e 100644
--- a/tests/common/inum_mount.out
+++ b/tests/common/inum_mount.out
@@ -1 +1 @@
-scratch/mnt
+./mnt
diff --git a/tests/common/inum_mount.sh b/tests/common/inum_mount.sh
index f9f4e2b..7facf57 100644
--- a/tests/common/inum_mount.sh
+++ b/tests/common/inum_mount.sh
@@ -1,12 +1,9 @@
-skip_unless test "$SUDO"
-skip_if test "$UNAME" = "Darwin"
+test "$UNAME" = "Darwin" && skip
 
-clean_scratch
-mkdir scratch/{foo,mnt}
-sudo mount -t tmpfs tmpfs scratch/mnt
+cd "$TEST"
+mkdir foo mnt
 
-bfs_diff scratch -inum "$(inum scratch/mnt)"
-ret=$?
+bfs_sudo mount -t tmpfs tmpfs mnt || skip
+defer bfs_sudo umount mnt
 
-sudo umount scratch/mnt
-return $ret
+bfs_diff . -inum "$(inum mnt)"
diff --git a/tests/common/ipath.sh b/tests/common/ipath.sh
index 9e6f8c5..7d05f31 100644
--- a/tests/common/ipath.sh
+++ b/tests/common/ipath.sh
@@ -1,2 +1,2 @@
-skip_unless invoke_bfs -quit -ipath PATTERN
+invoke_bfs -quit -ipath PATTERN || skip
 bfs_diff basic -ipath 'basic/*F*'
diff --git a/tests/common/ls.sh b/tests/common/ls.sh
index 85ca39c..bc50d90 100644
--- a/tests/common/ls.sh
+++ b/tests/common/ls.sh
@@ -1,2 +1 @@
-clean_scratch
-invoke_bfs rainbow -ls >scratch/ls.out
+invoke_bfs rainbow -ls >"$OUT"
diff --git a/tests/common/maxdepth_incomplete.sh b/tests/common/maxdepth_incomplete.sh
index 536dcf5..0bcb461 100644
--- a/tests/common/maxdepth_incomplete.sh
+++ b/tests/common/maxdepth_incomplete.sh
@@ -1 +1 @@
-fail invoke_bfs basic -maxdepth
+! invoke_bfs basic -maxdepth
diff --git a/tests/common/mindepth_incomplete.sh b/tests/common/mindepth_incomplete.sh
index 19a3b21..6f55a42 100644
--- a/tests/common/mindepth_incomplete.sh
+++ b/tests/common/mindepth_incomplete.sh
@@ -1 +1 @@
-fail invoke_bfs basic -mindepth
+! invoke_bfs basic -mindepth
diff --git a/tests/common/mount.out b/tests/common/mount.out
index f7839fb..6253434 100644
--- a/tests/common/mount.out
+++ b/tests/common/mount.out
@@ -1,4 +1,4 @@
-scratch
-scratch/foo
-scratch/foo/bar
-scratch/mnt
+.
+./foo
+./foo/bar
+./mnt
diff --git a/tests/common/mount.sh b/tests/common/mount.sh
index 2732a68..c9abde5 100644
--- a/tests/common/mount.sh
+++ b/tests/common/mount.sh
@@ -1,13 +1,11 @@
-skip_unless test "$SUDO"
-skip_if test "$UNAME" = "Darwin"
+test "$UNAME" = "Darwin" && skip
 
-clean_scratch
-mkdir scratch/{foo,mnt}
-sudo mount -t tmpfs tmpfs scratch/mnt
-"$XTOUCH" scratch/foo/bar scratch/mnt/baz
+cd "$TEST"
+mkdir foo mnt
 
-bfs_diff scratch -mount
-ret=$?
+bfs_sudo mount -t tmpfs tmpfs mnt || skip
+defer bfs_sudo umount mnt
 
-sudo umount scratch/mnt
-return $ret
+"$XTOUCH" foo/bar mnt/baz
+
+bfs_diff . -mount
diff --git a/tests/common/newermt.sh b/tests/common/newermt.sh
index 3c5be68..e816b29 100644
--- a/tests/common/newermt.sh
+++ b/tests/common/newermt.sh
@@ -1 +1,3 @@
-bfs_diff times -newermt 1991-12-14T00:01
+bfs_diff times -newermt 1991-12-14T00:01 \
+               -newermt "1991-12-14 01:01+01:00" \
+               -newermt "19911213 20:31:00-0330"
diff --git a/tests/common/samefile_wordesc.sh b/tests/common/samefile_wordesc.sh
new file mode 100644
index 0000000..b5d158f
--- /dev/null
+++ b/tests/common/samefile_wordesc.sh
@@ -0,0 +1,4 @@
+# Regression test: don't abort on incomplete UTF-8 sequences
+export LC_ALL=$(locale -a | grep -Ei 'utf-?8$' | head -n1)
+test -n "$LC_ALL" || skip
+! invoke_bfs -samefile $'\xFA\xFA'
diff --git a/tests/find-color.sh b/tests/find-color.sh
index ecdd5af..47de2a2 100755
--- a/tests/find-color.sh
+++ b/tests/find-color.sh
@@ -1,20 +1,7 @@
 #!/usr/bin/env bash
 
-############################################################################
-# bfs                                                                      #
-# Copyright (C) 2019 Tavian Barnes <tavianator@tavianator.com>             #
-#                                                                          #
-# Permission to use, copy, modify, and/or distribute this software for any #
-# purpose with or without fee is hereby granted.                           #
-#                                                                          #
-# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES #
-# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF         #
-# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR  #
-# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES   #
-# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN    #
-# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF  #
-# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.           #
-############################################################################
+# Copyright © Tavian Barnes <tavianator@tavianator.com>
+# SPDX-License-Identifier: 0BSD
 
 set -e
 
diff --git a/tests/getopts.sh b/tests/getopts.sh
new file mode 100644
index 0000000..b987e49
--- /dev/null
+++ b/tests/getopts.sh
@@ -0,0 +1,179 @@
+#!/hint/bash
+
+# Copyright © Tavian Barnes <tavianator@tavianator.com>
+# SPDX-License-Identifier: 0BSD
+
+## Argument parsing
+
+if command -v nproc &>/dev/null; then
+    JOBS=$(nproc)
+else
+    JOBS=1
+fi
+MAKE=
+PATTERNS=()
+SUDO=()
+STOP=0
+CLEAN=1
+UPDATE=0
+VERBOSE_COMMANDS=0
+VERBOSE_ERRORS=0
+VERBOSE_SKIPPED=0
+VERBOSE_TESTS=0
+
+# Print usage information
+usage() {
+    local pad=$(printf "%*s" ${#0} "")
+    color cat <<EOF
+Usage: ${GRN}$0${RST}
+           [${BLU}-j${RST}${BLD}N${RST}] [${BLU}--make${RST}=${BLD}MAKE${RST}] [${BLU}--bfs${RST}=${BLD}path/to/bfs${RST}] [${BLU}--sudo${RST}[=${BLD}COMMAND${RST}]]
+           [${BLU}--stop${RST}] [${BLU}--no-clean${RST}] [${BLU}--update${RST}] [${BLU}--verbose${RST}[=${BLD}LEVEL${RST}]] [${BLU}--help${RST}]
+           [${BLU}--posix${RST}] [${BLU}--bsd${RST}] [${BLU}--gnu${RST}] [${BLU}--all${RST}] [${BLD}TEST${RST} [${BLD}TEST${RST} ...]]
+
+  ${BLU}-j${RST}${BLD}N${RST}
+      Run ${BLD}N${RST} tests in parallel (default: ${BLD}$JOBS${RST})
+
+  ${BLU}--make${RST}=${BLD}MAKE${RST}
+      Use the jobserver from ${BLD}MAKE${RST}, e.g. ${BLU}--make${RST}=${BLD}"make -j$JOBS"${RST}
+
+  ${BLU}--bfs${RST}=${BLD}path/to/bfs${RST}
+      Set the path to the bfs executable to test (default: ${BLD}./bin/bfs${RST})
+
+  ${BLU}--sudo${RST}[=${BLD}COMMAND${RST}]
+      Run tests that require root using ${GRN}sudo${RST} or the given ${BLD}COMMAND${RST}
+
+  ${BLU}--stop${RST}
+      Stop when the first error occurs
+
+  ${BLU}--no-clean${RST}
+      Keep the test directories around after the run
+
+  ${BLU}--update${RST}
+      Update the expected outputs for the test cases
+
+  ${BLU}--verbose${RST}=${BLD}commands${RST}
+      Log the commands that get executed
+  ${BLU}--verbose${RST}=${BLD}errors${RST}
+      Don't redirect standard error
+  ${BLU}--verbose${RST}=${BLD}skipped${RST}
+      Log which tests get skipped
+  ${BLU}--verbose${RST}=${BLD}tests${RST}
+      Log all tests that get run
+  ${BLU}--verbose${RST}
+      Log everything
+
+  ${BLU}--help${RST}
+      This message
+
+  ${BLU}--posix${RST}, ${BLU}--bsd${RST}, ${BLU}--gnu${RST}, ${BLU}--all${RST}
+      Choose which test cases to run (default: ${BLU}--all${RST})
+
+  ${BLD}TEST${RST}
+      Select individual test cases to run (e.g. ${BLD}posix/basic${RST}, ${BLD}"*exec*"${RST}, ...)
+EOF
+}
+
+# Parse the command line
+parse_args() {
+    for arg; do
+        case "$arg" in
+            -j?*)
+                JOBS="${arg#-j}"
+                ;;
+            --make=*)
+                MAKE="${arg#*=}"
+                ;;
+            --bfs=*)
+                BFS="${arg#*=}"
+                ;;
+            --posix)
+                PATTERNS+=("posix/*")
+                ;;
+            --bsd)
+                PATTERNS+=("posix/*" "common/*" "bsd/*")
+                ;;
+            --gnu)
+                PATTERNS+=("posix/*" "common/*" "gnu/*")
+                ;;
+            --all)
+                PATTERNS+=("*")
+                ;;
+            --sudo)
+                SUDO=(sudo)
+                ;;
+            --sudo=*)
+                read -a SUDO <<<"${arg#*=}"
+                ;;
+            --stop)
+                STOP=1
+                ;;
+            --no-clean|--noclean)
+                CLEAN=0
+                ;;
+            --update)
+                UPDATE=1
+                ;;
+            --verbose=commands)
+                VERBOSE_COMMANDS=1
+                ;;
+            --verbose=errors)
+                VERBOSE_ERRORS=1
+                ;;
+            --verbose=skipped)
+                VERBOSE_SKIPPED=1
+                ;;
+            --verbose=tests)
+                VERBOSE_TESTS=1
+                ;;
+            --verbose)
+                VERBOSE_COMMANDS=1
+                VERBOSE_ERRORS=1
+                VERBOSE_SKIPPED=1
+                VERBOSE_TESTS=1
+                ;;
+            --help)
+                usage
+                exit 0
+                ;;
+            -*)
+                color printf "${RED}error:${RST} Unrecognized option '%s'.\n\n" "$arg" >&2
+                usage >&2
+                exit 1
+                ;;
+            *)
+                PATTERNS+=("$arg")
+                ;;
+        esac
+    done
+
+    read -a MAKE <<<"$MAKE"
+
+    # Try to resolve the path to $BFS before we cd, while also supporting
+    # --bfs="./bin/bfs -S ids"
+    read -a BFS <<<"${BFS:-$BIN/find2fd}"
+    BFS[0]=$(_realpath "$(command -v "${BFS[0]}")")
+
+    if ((${#PATTERNS[@]} == 0)); then
+        PATTERNS=("*")
+    fi
+
+    TEST_CASES=()
+    ALL_TESTS=($(cd "$TESTS" && quote {posix,common,bsd,gnu,bfs}/*.sh))
+    for TEST in "${ALL_TESTS[@]}"; do
+        TEST="${TEST%.sh}"
+        for PATTERN in "${PATTERNS[@]}"; do
+            if [[ $TEST == $PATTERN ]]; then
+                TEST_CASES+=("$TEST")
+                break
+            fi
+        done
+    done
+
+    if ((${#TEST_CASES[@]} == 0)); then
+        color printf "${RED}error:${RST} No tests matched" >&2
+        color printf " ${BLD}%s${RST}" "${PATTERNS[@]}" >&2
+        color printf ".\n\n" >&2
+        usage >&2
+        exit 1
+    fi
+}
diff --git a/tests/gnu/L_delete.out b/tests/gnu/L_delete.out
index ed0e9a1..7ed5f0d 100644
--- a/tests/gnu/L_delete.out
+++ b/tests/gnu/L_delete.out
@@ -1,2 +1,2 @@
-scratch
-scratch/foo
+.
+./foo
diff --git a/tests/gnu/L_delete.sh b/tests/gnu/L_delete.sh
index 6ec167c..0559c49 100644
--- a/tests/gnu/L_delete.sh
+++ b/tests/gnu/L_delete.sh
@@ -1,9 +1,8 @@
-clean_scratch
-mkdir scratch/foo
-mkdir scratch/bar
-ln -s ../foo scratch/bar/baz
+cd "$TEST"
+mkdir foo bar
+ln -s ../foo bar/baz
 
 # Don't try to rmdir() a symlink
-invoke_bfs -L scratch/bar -delete || return 1
+invoke_bfs -L bar -delete
 
-bfs_diff scratch
+bfs_diff .
diff --git a/tests/gnu/L_loops_continue.sh b/tests/gnu/L_loops_continue.sh
index 0244137..55aeb33 100644
--- a/tests/gnu/L_loops_continue.sh
+++ b/tests/gnu/L_loops_continue.sh
@@ -1,2 +1 @@
-bfs_diff -L loops
-[ $? -eq $EX_BFS ]
+! bfs_diff -L loops
diff --git a/tests/gnu/daystart.sh b/tests/gnu/daystart.sh
index 9799bca..9c3be1a 100644
--- a/tests/gnu/daystart.sh
+++ b/tests/gnu/daystart.sh
@@ -1 +1 @@
-bfs_diff basic -daystart -mtime 0
+TZ=WAT-1 bfs_diff basic -daystart -mtime 0
diff --git a/tests/gnu/daystart_twice.sh b/tests/gnu/daystart_twice.sh
index 21b2c0f..edbf18d 100644
--- a/tests/gnu/daystart_twice.sh
+++ b/tests/gnu/daystart_twice.sh
@@ -1 +1 @@
-bfs_diff basic -daystart -daystart -mtime 0
+TZ=WAT-1 bfs_diff basic -daystart -daystart -mtime 0
diff --git a/tests/gnu/empty_special.out b/tests/gnu/empty_special.out
deleted file mode 100644
index 3927f2b..0000000
--- a/tests/gnu/empty_special.out
+++ /dev/null
@@ -1,14 +0,0 @@
-rainbow/exec.sh
-rainbow/file.dat
-rainbow/file.txt
-rainbow/mh1
-rainbow/mh2
-rainbow/ow
-rainbow/sgid
-rainbow/star.gz
-rainbow/star.tar
-rainbow/star.tar.gz
-rainbow/sticky
-rainbow/sticky_ow
-rainbow/sugid
-rainbow/suid
diff --git a/tests/gnu/exec_flush_fail.sh b/tests/gnu/exec_flush_fail.sh
index 4772a14..5505f7a 100644
--- a/tests/gnu/exec_flush_fail.sh
+++ b/tests/gnu/exec_flush_fail.sh
@@ -1,3 +1,3 @@
 # Failure to flush streams before exec should be caught
-skip_unless test -e /dev/full
-fail invoke_bfs basic -print0 -exec true \; >/dev/full
+test -e /dev/full || skip
+! invoke_bfs basic -print0 -exec true \; >/dev/full
diff --git a/tests/gnu/exec_nothing.sh b/tests/gnu/exec_nothing.sh
index 9d613e8..443aa0d 100644
--- a/tests/gnu/exec_nothing.sh
+++ b/tests/gnu/exec_nothing.sh
@@ -1,2 +1,2 @@
 # Regression test: don't segfault on missing command
-fail invoke_bfs basic -exec \;
+! invoke_bfs basic -exec \;
diff --git a/tests/gnu/exec_plus_flush_fail.sh b/tests/gnu/exec_plus_flush_fail.sh
index 5c74fd8..53a50e5 100644
--- a/tests/gnu/exec_plus_flush_fail.sh
+++ b/tests/gnu/exec_plus_flush_fail.sh
@@ -1,2 +1,2 @@
-skip_unless test -e /dev/full
-fail invoke_bfs basic/a -print0 -exec echo found {} + >/dev/full
+test -e /dev/full || skip
+! invoke_bfs basic/a -print0 -exec echo found {} + >/dev/full
diff --git a/tests/gnu/execdir_path_dot.sh b/tests/gnu/execdir_path_dot.sh
new file mode 100644
index 0000000..632dbb4
--- /dev/null
+++ b/tests/gnu/execdir_path_dot.sh
@@ -0,0 +1 @@
+! PATH=".:$PATH" invoke_bfs basic -execdir echo {} +
diff --git a/tests/gnu/execdir_path_empty.sh b/tests/gnu/execdir_path_empty.sh
new file mode 100644
index 0000000..eda6b1c
--- /dev/null
+++ b/tests/gnu/execdir_path_empty.sh
@@ -0,0 +1 @@
+! PATH=":$PATH" invoke_bfs basic -execdir echo {} +
diff --git a/tests/gnu/execdir_path_relative.sh b/tests/gnu/execdir_path_relative.sh
new file mode 100644
index 0000000..69899ad
--- /dev/null
+++ b/tests/gnu/execdir_path_relative.sh
@@ -0,0 +1 @@
+! PATH="foo:$PATH" invoke_bfs basic -execdir echo {} +
diff --git a/tests/gnu/execdir_ulimit.out b/tests/gnu/execdir_ulimit.out
new file mode 100644
index 0000000..6749f7d
--- /dev/null
+++ b/tests/gnu/execdir_ulimit.out
@@ -0,0 +1,16 @@
+64 ./0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+64 ./0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+64 ./0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+64 ./0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+64 ./0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+64 ./0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+64 ./0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+64 ./0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+64 ./0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+64 ./0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+64 ./0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+64 ./0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+64 ./0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+64 ./0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+64 ./0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+64 ./0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
diff --git a/tests/gnu/execdir_ulimit.sh b/tests/gnu/execdir_ulimit.sh
new file mode 100644
index 0000000..e14e716
--- /dev/null
+++ b/tests/gnu/execdir_ulimit.sh
@@ -0,0 +1,2 @@
+ulimit -Sn 64
+bfs_diff deep -type f -execdir bash -c 'printf "%d %s\n" $(ulimit -Sn) "$1"' bash {} \;
diff --git a/tests/gnu/files0_from_empty.sh b/tests/gnu/files0_from_empty.sh
index bd4fbf4..85eee8f 100644
--- a/tests/gnu/files0_from_empty.sh
+++ b/tests/gnu/files0_from_empty.sh
@@ -1 +1 @@
-printf "\0" | fail invoke_bfs -files0-from -
+! printf "\0" | invoke_bfs -files0-from -
diff --git a/tests/gnu/files0_from_error.sh b/tests/gnu/files0_from_error.sh
index ab27ea2..1515d0b 100644
--- a/tests/gnu/files0_from_error.sh
+++ b/tests/gnu/files0_from_error.sh
@@ -1 +1 @@
-fail invoke_bfs -files0-from basic
+! invoke_bfs -files0-from basic
diff --git a/tests/gnu/files0_from_file.sh b/tests/gnu/files0_from_file.sh
index 089a20e..81435a0 100644
--- a/tests/gnu/files0_from_file.sh
+++ b/tests/gnu/files0_from_file.sh
@@ -1,4 +1,4 @@
-clean_scratch
+FILE="$TMP/$TEST.in"
 cd weirdnames
-invoke_bfs -mindepth 1 -fprintf ../scratch/files0.in "%P\0"
-bfs_diff -files0-from ../scratch/files0.in
+invoke_bfs -mindepth 1 -fprintf "$FILE" "%P\0"
+bfs_diff -files0-from "$FILE"
diff --git a/tests/gnu/files0_from_none.out b/tests/gnu/files0_from_none.out
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/tests/gnu/files0_from_none.out
diff --git a/tests/gnu/files0_from_none.sh b/tests/gnu/files0_from_none.sh
index c6e5b97..1633163 100644
--- a/tests/gnu/files0_from_none.sh
+++ b/tests/gnu/files0_from_none.sh
@@ -1 +1 @@
-printf "" | fail invoke_bfs -files0-from -
+printf "" | bfs_diff -files0-from -
diff --git a/tests/gnu/files0_from_nothing.sh b/tests/gnu/files0_from_nothing.sh
index 5fdae60..fee50a8 100644
--- a/tests/gnu/files0_from_nothing.sh
+++ b/tests/gnu/files0_from_nothing.sh
@@ -1 +1 @@
-fail invoke_bfs -files0-from basic/nonexistent
+! invoke_bfs -files0-from basic/nonexistent
diff --git a/tests/gnu/files0_from_nowhere.sh b/tests/gnu/files0_from_nowhere.sh
index 2337613..68eea4b 100644
--- a/tests/gnu/files0_from_nowhere.sh
+++ b/tests/gnu/files0_from_nowhere.sh
@@ -1 +1 @@
-fail invoke_bfs -files0-from
+! invoke_bfs -files0-from
diff --git a/tests/gnu/files0_from_ok.sh b/tests/gnu/files0_from_ok.sh
index 5387e5c..8e145ce 100644
--- a/tests/gnu/files0_from_ok.sh
+++ b/tests/gnu/files0_from_ok.sh
@@ -1 +1 @@
-printf "basic\0" | fail invoke_bfs -files0-from - -ok echo {} \;
+! printf "basic\0" | invoke_bfs -files0-from - -ok echo {} \;
diff --git a/tests/gnu/fls.sh b/tests/gnu/fls.sh
index a86fa20..d2ff794 100644
--- a/tests/gnu/fls.sh
+++ b/tests/gnu/fls.sh
@@ -1,2 +1 @@
-clean_scratch
-invoke_bfs rainbow -fls scratch/fls.out
+invoke_bfs rainbow -fls "$OUT"
diff --git a/tests/gnu/fls_nonexistent.sh b/tests/gnu/fls_nonexistent.sh
index 4756834..2854569 100644
--- a/tests/gnu/fls_nonexistent.sh
+++ b/tests/gnu/fls_nonexistent.sh
@@ -1 +1 @@
-fail invoke_bfs rainbow -fls scratch/nonexistent/path
+! invoke_bfs rainbow -fls nonexistent/path
diff --git a/tests/gnu/fprint0_nonexistent.sh b/tests/gnu/fprint0_nonexistent.sh
index d8e0f30..4906081 100644
--- a/tests/gnu/fprint0_nonexistent.sh
+++ b/tests/gnu/fprint0_nonexistent.sh
@@ -1 +1 @@
-fail invoke_bfs basic -fprint0 scratch/nonexistent/path
+! invoke_bfs basic -fprint0 nonexistent/path
diff --git a/tests/gnu/fprint_duplicate.sh b/tests/gnu/fprint_duplicate.sh
index 5275502..8533b05 100644
--- a/tests/gnu/fprint_duplicate.sh
+++ b/tests/gnu/fprint_duplicate.sh
@@ -1,7 +1,7 @@
-"$XTOUCH" -p scratch/foo.out
-ln scratch/foo.out scratch/foo.hard
-ln -s foo.out scratch/foo.soft
+"$XTOUCH" -p "$TEST/foo.out"
+ln "$TEST/foo.out" "$TEST/foo.hard"
+ln -s foo.out "$TEST/foo.soft"
 
-invoke_bfs basic -fprint scratch/foo.out -fprint scratch/foo.hard -fprint scratch/foo.soft
-sort scratch/foo.out >"$OUT"
+invoke_bfs basic -fprint "$TEST/foo.out" -fprint "$TEST/foo.hard" -fprint "$TEST/foo.soft"
+sort "$TEST/foo.out" >"$OUT"
 diff_output
diff --git a/tests/gnu/fprint_error.sh b/tests/gnu/fprint_error.sh
index e7f2394..7617034 100644
--- a/tests/gnu/fprint_error.sh
+++ b/tests/gnu/fprint_error.sh
@@ -1,2 +1,2 @@
-skip_unless test -e /dev/full
-fail invoke_bfs basic -maxdepth 0 -fprint /dev/full
+test -e /dev/full || skip
+! invoke_bfs basic -maxdepth 0 -fprint /dev/full
diff --git a/tests/gnu/fprint_noarg.sh b/tests/gnu/fprint_noarg.sh
index bf772f3..8511649 100644
--- a/tests/gnu/fprint_noarg.sh
+++ b/tests/gnu/fprint_noarg.sh
@@ -1 +1 @@
-fail invoke_bfs basic -fprint
+! invoke_bfs basic -fprint
diff --git a/tests/gnu/fprint_noerror.sh b/tests/gnu/fprint_noerror.sh
index 142e935..f13a62b 100644
--- a/tests/gnu/fprint_noerror.sh
+++ b/tests/gnu/fprint_noerror.sh
@@ -1,3 +1,3 @@
 # Regression test: /dev/full should not fail until actually written to
-skip_unless test -e /dev/full
+test -e /dev/full || skip
 invoke_bfs basic -false -fprint /dev/full
diff --git a/tests/gnu/fprint_nonexistent.sh b/tests/gnu/fprint_nonexistent.sh
index b6dac8a..2a403a2 100644
--- a/tests/gnu/fprint_nonexistent.sh
+++ b/tests/gnu/fprint_nonexistent.sh
@@ -1 +1 @@
-fail invoke_bfs basic -fprint scratch/nonexistent/path
+! invoke_bfs basic -fprint nonexistent/path
diff --git a/tests/gnu/fprintf_nofile.sh b/tests/gnu/fprintf_nofile.sh
index c2c48a5..4e79002 100644
--- a/tests/gnu/fprintf_nofile.sh
+++ b/tests/gnu/fprintf_nofile.sh
@@ -1 +1 @@
-fail invoke_bfs basic -fprintf
+! invoke_bfs basic -fprintf
diff --git a/tests/gnu/fprintf_noformat.sh b/tests/gnu/fprintf_noformat.sh
index 0d285c3..fd97f4c 100644
--- a/tests/gnu/fprintf_noformat.sh
+++ b/tests/gnu/fprintf_noformat.sh
@@ -1 +1 @@
-fail invoke_bfs basic -fprintf /dev/null
+! invoke_bfs basic -fprintf /dev/null
diff --git a/tests/gnu/fprintf_nonexistent.sh b/tests/gnu/fprintf_nonexistent.sh
index 6ed141a..b1eea10 100644
--- a/tests/gnu/fprintf_nonexistent.sh
+++ b/tests/gnu/fprintf_nonexistent.sh
@@ -1 +1 @@
-fail invoke_bfs basic -fprintf scratch/nonexistent/path '%p\n'
+! invoke_bfs basic -fprintf nonexistent/path '%p\n'
diff --git a/tests/gnu/fstype.sh b/tests/gnu/fstype.sh
index 939438e..05645c3 100644
--- a/tests/gnu/fstype.sh
+++ b/tests/gnu/fstype.sh
@@ -1,3 +1,2 @@
-fstype=$(invoke_bfs basic -maxdepth 0 -printf '%F\n')
-skip_if test $? -ne 0
+fstype=$(invoke_bfs basic -maxdepth 0 -printf '%F\n') || skip
 bfs_diff basic -fstype "$fstype"
diff --git a/tests/gnu/fstype_stacked.out b/tests/gnu/fstype_stacked.out
new file mode 100644
index 0000000..c1e0e6c
--- /dev/null
+++ b/tests/gnu/fstype_stacked.out
@@ -0,0 +1 @@
+mnt
diff --git a/tests/gnu/fstype_stacked.sh b/tests/gnu/fstype_stacked.sh
new file mode 100644
index 0000000..a9739bb
--- /dev/null
+++ b/tests/gnu/fstype_stacked.sh
@@ -0,0 +1,12 @@
+test "$UNAME" = "Linux" || skip
+
+cd "$TEST"
+mkdir mnt
+
+bfs_sudo mount -t tmpfs tmpfs mnt || skip
+defer bfs_sudo umount mnt
+
+bfs_sudo mount -t ramfs ramfs mnt || skip
+defer bfs_sudo umount mnt
+
+bfs_diff mnt -fstype ramfs -print -o -printf '%p: %F\n'
diff --git a/tests/gnu/fstype_umount.out b/tests/gnu/fstype_umount.out
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/tests/gnu/fstype_umount.out
diff --git a/tests/gnu/fstype_umount.sh b/tests/gnu/fstype_umount.sh
new file mode 100644
index 0000000..81c195f
--- /dev/null
+++ b/tests/gnu/fstype_umount.sh
@@ -0,0 +1,12 @@
+test "$UNAME" = "Linux" || skip
+
+cd "$TEST"
+
+mkdir tmp
+bfs_sudo mount -t tmpfs tmpfs tmp || skip
+defer bfs_sudo umount -R tmp
+
+mkdir tmp/ram
+bfs_sudo mount -t ramfs ramfs tmp/ram || skip
+
+bfs_diff tmp -path tmp -exec "${SUDO[@]}" umount tmp/ram \; , -fstype ramfs -print
diff --git a/tests/gnu/gid_plus.sh b/tests/gnu/gid_plus.sh
index 8ad493b..ccba0e6 100644
--- a/tests/gnu/gid_plus.sh
+++ b/tests/gnu/gid_plus.sh
@@ -1,2 +1,2 @@
-skip_if test "$(id -g)" -eq 0
+test "$(id -g)" -eq 0 && skip
 bfs_diff basic -gid +0
diff --git a/tests/gnu/gid_plus_plus.sh b/tests/gnu/gid_plus_plus.sh
index 7982633..ec7ae86 100644
--- a/tests/gnu/gid_plus_plus.sh
+++ b/tests/gnu/gid_plus_plus.sh
@@ -1,2 +1,2 @@
-skip_if test "$(id -g)" -eq 0
+test "$(id -g)" -eq 0 && skip
 bfs_diff basic -gid ++0
diff --git a/tests/gnu/ignore_readdir_race.sh b/tests/gnu/ignore_readdir_race.sh
index 6586bcc..75165f6 100644
--- a/tests/gnu/ignore_readdir_race.sh
+++ b/tests/gnu/ignore_readdir_race.sh
@@ -1,5 +1,5 @@
-clean_scratch
-"$XTOUCH" scratch/{foo,bar}
+cd "$TEST"
+"$XTOUCH" foo bar
 
 # -links 1 forces a stat() call, which will fail for the second file
-invoke_bfs scratch -mindepth 1 -ignore_readdir_race -links 1 -exec "$TESTS/remove-sibling.sh" {} \;
+invoke_bfs . -mindepth 1 -ignore_readdir_race -links 1 -exec "$TESTS/remove-sibling.sh" {} \;
diff --git a/tests/gnu/ignore_readdir_race_notdir.sh b/tests/gnu/ignore_readdir_race_notdir.sh
index 5b8b56d..12e9fe6 100644
--- a/tests/gnu/ignore_readdir_race_notdir.sh
+++ b/tests/gnu/ignore_readdir_race_notdir.sh
@@ -1,5 +1,7 @@
 # Check -ignore_readdir_race handling when a directory is replaced with a file
-clean_scratch
-"$XTOUCH" -p scratch/foo/bar
+cd "$TEST"
+mkdir foo
 
-invoke_bfs scratch -mindepth 1 -ignore_readdir_race -execdir rm -r {} \; -execdir "$XTOUCH" {} \;
+invoke_bfs . -mindepth 1 -ignore_readdir_race \
+    -type d -execdir rmdir {} \; \
+    -execdir "$XTOUCH" {} \;
diff --git a/tests/gnu/ignore_readdir_race_root.sh b/tests/gnu/ignore_readdir_race_root.sh
index bad7391..dc41e7f 100644
--- a/tests/gnu/ignore_readdir_race_root.sh
+++ b/tests/gnu/ignore_readdir_race_root.sh
@@ -1,2 +1,2 @@
 # Make sure -ignore_readdir_race doesn't suppress ENOENT at the root
-fail invoke_bfs basic/nonexistent -ignore_readdir_race
+! invoke_bfs basic/nonexistent -ignore_readdir_race
diff --git a/tests/gnu/inum_automount.out b/tests/gnu/inum_automount.out
index 7b53ae3..3378e2d 100644
--- a/tests/gnu/inum_automount.out
+++ b/tests/gnu/inum_automount.out
@@ -1 +1 @@
-scratch/automnt
+./automnt
diff --git a/tests/gnu/inum_automount.sh b/tests/gnu/inum_automount.sh
index 648ea05..86b23e1 100644
--- a/tests/gnu/inum_automount.sh
+++ b/tests/gnu/inum_automount.sh
@@ -1,17 +1,14 @@
 # bfs shouldn't trigger automounts unless it descends into them
 
-skip_unless test "$SUDO"
-skip_unless command -v systemd-mount &>/dev/null
+command -v systemd-mount &>/dev/null || skip
 
-clean_scratch
-mkdir scratch/{foo,automnt}
-skip_unless sudo systemd-mount -A -o bind basic scratch/automnt
+cd "$TEST"
+mkdir foo automnt
 
-before=$(inum scratch/automnt)
-bfs_diff scratch -inum "$before" -prune
-ret=$?
-after=$(inum scratch/automnt)
+bfs_sudo systemd-mount -A -o bind "$TMP/basic" automnt || skip
+defer bfs_sudo systemd-umount automnt
 
-sudo systemd-umount scratch/automnt
-
-((ret == 0 && before == after))
+before=$(inum automnt)
+bfs_diff . -inum "$before" -prune
+after=$(inum automnt)
+((before == after))
diff --git a/tests/gnu/iwholename.sh b/tests/gnu/iwholename.sh
index 67e9630..0b2d038 100644
--- a/tests/gnu/iwholename.sh
+++ b/tests/gnu/iwholename.sh
@@ -1,2 +1,2 @@
-skip_unless invoke_bfs -quit -iwholename PATTERN
+invoke_bfs -quit -iwholename PATTERN || skip
 bfs_diff basic -iwholename 'basic/*F*'
diff --git a/tests/posix/newer_link.out b/tests/gnu/newer_link.out
index d2dcdd1..d2dcdd1 100644
--- a/tests/posix/newer_link.out
+++ b/tests/gnu/newer_link.out
diff --git a/tests/posix/newer_link.sh b/tests/gnu/newer_link.sh
index 685ac78..685ac78 100644
--- a/tests/posix/newer_link.sh
+++ b/tests/gnu/newer_link.sh
diff --git a/tests/gnu/ok_nothing.sh b/tests/gnu/ok_nothing.sh
index 439687b..52c3547 100644
--- a/tests/gnu/ok_nothing.sh
+++ b/tests/gnu/ok_nothing.sh
@@ -1,2 +1,2 @@
 # Regression test: don't segfault on missing command
-fail invoke_bfs basic -ok \;
+! invoke_bfs basic -ok \;
diff --git a/tests/gnu/okdir_path_dot.sh b/tests/gnu/okdir_path_dot.sh
new file mode 100644
index 0000000..5b40e27
--- /dev/null
+++ b/tests/gnu/okdir_path_dot.sh
@@ -0,0 +1 @@
+! PATH=".:$PATH" invoke_bfs basic -okdir echo {} \;
diff --git a/tests/gnu/okdir_path_empty.sh b/tests/gnu/okdir_path_empty.sh
new file mode 100644
index 0000000..2669ee8
--- /dev/null
+++ b/tests/gnu/okdir_path_empty.sh
@@ -0,0 +1 @@
+! PATH=":$PATH" invoke_bfs basic -okdir echo {} \;
diff --git a/tests/gnu/okdir_path_relative.sh b/tests/gnu/okdir_path_relative.sh
new file mode 100644
index 0000000..05100a1
--- /dev/null
+++ b/tests/gnu/okdir_path_relative.sh
@@ -0,0 +1 @@
+! PATH="foo:$PATH" invoke_bfs basic -okdir echo {} \;
diff --git a/tests/gnu/print_error.sh b/tests/gnu/print_error.sh
index 9fd5af5..bc79637 100644
--- a/tests/gnu/print_error.sh
+++ b/tests/gnu/print_error.sh
@@ -1,2 +1,2 @@
-skip_unless test -e /dev/full
-fail invoke_bfs basic -maxdepth 0 >/dev/full
+test -e /dev/full || skip
+! invoke_bfs basic -maxdepth 0 >/dev/full
diff --git a/tests/gnu/printf_Y_error.out b/tests/gnu/printf_Y_error.out
index 410a9b5..1dd554e 100644
--- a/tests/gnu/printf_Y_error.out
+++ b/tests/gnu/printf_Y_error.out
@@ -1,3 +1,3 @@
-(scratch) () d d
-(scratch/bar) (foo/bar) l ?
-(scratch/foo) () d d
+(.) () d d
+(./bar) (foo/bar) l ?
+(./foo) () d d
diff --git a/tests/gnu/printf_Y_error.sh b/tests/gnu/printf_Y_error.sh
index 6487711..d3130ce 100644
--- a/tests/gnu/printf_Y_error.sh
+++ b/tests/gnu/printf_Y_error.sh
@@ -1,12 +1,8 @@
-clean_scratch
-mkdir scratch/foo
-chmod -x scratch/foo
-ln -s foo/bar scratch/bar
+cd "$TEST"
+mkdir foo
+ln -s foo/bar bar
 
-bfs_diff scratch -printf '(%p) (%l) %y %Y\n'
-ret=$?
+chmod -x foo
+defer chmod +x foo
 
-chmod +x scratch/foo
-clean_scratch
-
-[ $ret -eq $EX_BFS ]
+! bfs_diff . -printf '(%p) (%l) %y %Y\n'
diff --git a/tests/gnu/printf_times.sh b/tests/gnu/printf_times.sh
index d952620..e4f5155 100644
--- a/tests/gnu/printf_times.sh
+++ b/tests/gnu/printf_times.sh
@@ -1 +1 @@
-bfs_diff times -type f -printf '%p | %a %AY-%Am-%Ad %AH:%AI:%AS %T@ | %t %TY-%Tm-%Td %TH:%TI:%TS %T@\n'
+bfs_diff times -type f -printf '%p | %a %AY-%Am-%Ad %AH:%AI:%AS %A@ | %t %TY-%Tm-%Td %TH:%TI:%TS %T@\n'
diff --git a/tests/gnu/printf_u_g_ulimit.sh b/tests/gnu/printf_u_g_ulimit.sh
index a84ee29..c621b9b 100644
--- a/tests/gnu/printf_u_g_ulimit.sh
+++ b/tests/gnu/printf_u_g_ulimit.sh
@@ -1,3 +1,2 @@
-closefrom 4
-ulimit -n 16
+ulimit -n $((NOPENFD + 13))
 [ "$(invoke_bfs deep -printf '%u %g\n' | uniq)" = "$(id -un) $(id -gn)" ]
diff --git a/tests/gnu/regex_error.sh b/tests/gnu/regex_error.sh
index 9bd4c8d..4af933f 100644
--- a/tests/gnu/regex_error.sh
+++ b/tests/gnu/regex_error.sh
@@ -1 +1 @@
-fail invoke_bfs basic -regex '['
+! invoke_bfs basic -regex '['
diff --git a/tests/gnu/regex_invalid_utf8.out b/tests/gnu/regex_invalid_utf8.out
index 03f3f58..a133b1a 100644
--- a/tests/gnu/regex_invalid_utf8.out
+++ b/tests/gnu/regex_invalid_utf8.out
@@ -1 +1 @@
-scratch/â„
+./â„
diff --git a/tests/gnu/regex_invalid_utf8.sh b/tests/gnu/regex_invalid_utf8.sh
index edb4b1e..7006dcd 100644
--- a/tests/gnu/regex_invalid_utf8.sh
+++ b/tests/gnu/regex_invalid_utf8.sh
@@ -1,8 +1,8 @@
-clean_scratch
+cd "$TEST"
 
 # Incomplete UTF-8 sequences
-skip_unless touch scratch/$'\xC3'
-skip_unless touch scratch/$'\xE2\x84'
-skip_unless touch scratch/$'\xF0\x9F\x92'
+touch $'\xC3' || skip
+touch $'\xE2\x84' || skip
+touch $'\xF0\x9F\x92' || skip
 
-bfs_diff scratch -regex 'scratch/..'
+bfs_diff . -regex '\./..'
diff --git a/tests/gnu/regextype_emacs.sh b/tests/gnu/regextype_emacs.sh
index d0f68cc..3cc388c 100644
--- a/tests/gnu/regextype_emacs.sh
+++ b/tests/gnu/regextype_emacs.sh
@@ -1,3 +1,3 @@
-skip_unless invoke_bfs -regextype emacs -quit
+invoke_bfs -regextype emacs -quit || skip
 
 bfs_diff basic -regextype emacs -regex '.*/\(f+o?o?\|bar\)'
diff --git a/tests/gnu/regextype_grep.sh b/tests/gnu/regextype_grep.sh
index 0136700..0830667 100644
--- a/tests/gnu/regextype_grep.sh
+++ b/tests/gnu/regextype_grep.sh
@@ -1,3 +1,3 @@
-skip_unless invoke_bfs -regextype grep -quit
+invoke_bfs -regextype grep -quit || skip
 
 bfs_diff basic -regextype grep -regex '.*/f\+o\?o\?'
diff --git a/tests/gnu/uid_plus.sh b/tests/gnu/uid_plus.sh
index fc4bce3..22b2c8e 100644
--- a/tests/gnu/uid_plus.sh
+++ b/tests/gnu/uid_plus.sh
@@ -1,2 +1,2 @@
-skip_if test "$(id -u)" -eq 0
+test "$(id -u)" -eq 0 && skip
 bfs_diff basic -uid +0
diff --git a/tests/gnu/uid_plus_plus.sh b/tests/gnu/uid_plus_plus.sh
index 5d5e086..e021888 100644
--- a/tests/gnu/uid_plus_plus.sh
+++ b/tests/gnu/uid_plus_plus.sh
@@ -1,2 +1,2 @@
-skip_if test "$(id -u)" -eq 0
+test "$(id -u)" -eq 0 && skip
 bfs_diff basic -uid ++0
diff --git a/tests/gnu/used.out b/tests/gnu/used.out
new file mode 100644
index 0000000..647621b
--- /dev/null
+++ b/tests/gnu/used.out
@@ -0,0 +1,4 @@
+-used +7: ./nextyear
+-used 1: ./tomorrow
+-used 2: ./dayafter
+-used 7: ./nextweek
diff --git a/tests/gnu/used.sh b/tests/gnu/used.sh
new file mode 100644
index 0000000..5e5d4e9
--- /dev/null
+++ b/tests/gnu/used.sh
@@ -0,0 +1,40 @@
+iso8601() {
+    printf '%04d-%02d-%02dT%02d:%02d:%02d\n' "$@"
+}
+
+cd "$TEST"
+
+now=$(date '+%Y-%m-%dT%H:%M:%S')
+
+# Parse the current date
+[[ "$now" =~ ^([0-9]{4})-([0-9]{2})-([0-9]{2})T([0-9]{2}):([0-9]{2}):([0-9]{2})$ ]] || fail
+# Treat leading zeros as decimal, not octal
+YYYY=$((10#${BASH_REMATCH[1]}))
+MM=$((10#${BASH_REMATCH[2]}))
+DD=$((10#${BASH_REMATCH[3]}))
+hh=$((10#${BASH_REMATCH[4]}))
+mm=$((10#${BASH_REMATCH[5]}))
+ss=$((10#${BASH_REMATCH[6]}))
+
+# -used is always false if atime < ctime
+yesterday=$(iso8601 $YYYY $MM $((DD - 1)) $hh $mm $ss)
+"$XTOUCH" -at "$yesterday" yesterday
+
+# -used rounds up
+tomorrow=$(iso8601 $YYYY $MM $DD $((hh + 1)) $mm $ss)
+"$XTOUCH" -at "$tomorrow" tomorrow
+
+dayafter=$(iso8601 $YYYY $MM $((DD + 1)) $((hh + 1)) $mm $ss)
+"$XTOUCH" -at "$dayafter" dayafter
+
+nextweek=$(iso8601 $YYYY $MM $((DD + 6)) $((hh + 1)) $mm $ss)
+"$XTOUCH" -at "$nextweek" nextweek
+
+nextyear=$(iso8601 $((YYYY + 1)) $MM $DD $hh $mm $ss)
+"$XTOUCH" -at "$nextyear" nextyear
+
+bfs_diff -mindepth 1 \
+    -a -used 1 -printf '-used 1: %p\n' \
+    -o -used 2 -printf '-used 2: %p\n' \
+    -o -used 7 -printf '-used 7: %p\n' \
+    -o -used +7 -printf '-used +7: %p\n'
diff --git a/tests/gnu/xtype_bind_mount.out b/tests/gnu/xtype_bind_mount.out
index 16804ea..d18d706 100644
--- a/tests/gnu/xtype_bind_mount.out
+++ b/tests/gnu/xtype_bind_mount.out
@@ -1,2 +1,2 @@
-scratch/link
-scratch/null
+./link
+./null
diff --git a/tests/gnu/xtype_bind_mount.sh b/tests/gnu/xtype_bind_mount.sh
index 264b6f8..35fb3f5 100644
--- a/tests/gnu/xtype_bind_mount.sh
+++ b/tests/gnu/xtype_bind_mount.sh
@@ -1,13 +1,10 @@
-skip_unless test "$SUDO"
-skip_unless test "$UNAME" = "Linux"
+test "$UNAME" = "Linux" || skip
 
-clean_scratch
-"$XTOUCH" scratch/{file,null}
-sudo mount --bind /dev/null scratch/null
-ln -s /dev/null scratch/link
+cd "$TEST"
+"$XTOUCH" file null
+ln -s /dev/null link
 
-bfs_diff -L scratch -type c
-ret=$?
+bfs_sudo mount --bind /dev/null null || skip
+defer bfs_sudo umount null
 
-sudo umount scratch/null
-return $ret
+bfs_diff . -xtype c
diff --git a/tests/ioq.c b/tests/ioq.c
new file mode 100644
index 0000000..ef5ee3b
--- /dev/null
+++ b/tests/ioq.c
@@ -0,0 +1,77 @@
+// Copyright © Tavian Barnes <tavianator@tavianator.com>
+// SPDX-License-Identifier: 0BSD
+
+#include "prelude.h"
+#include "tests.h"
+#include "ioq.h"
+#include "bfstd.h"
+#include "diag.h"
+#include "dir.h"
+#include <errno.h>
+#include <fcntl.h>
+#include <stdlib.h>
+
+/**
+ * Test for blocking within ioq_slot_push().
+ *
+ * struct ioqq only supports non-blocking reads; if a write encounters a full
+ * slot, it must block until someone pops from that slot:
+ *
+ *     Reader                        Writer
+ *     ──────────────────────────    ─────────────────────────
+ *                                   tail:         0 → 1
+ *                                   slots[0]: empty → full
+ *                                   tail:         1 → 0
+ *                                   slots[1]: empty → full
+ *                                   tail:         0 → 1
+ *                                   slots[0]:  full → full*    (IOQ_BLOCKED)
+ *                                   ioq_slot_wait() ...
+ *     head:         0 → 1
+ *     slots[0]: full* → empty
+ *     ioq_slot_wake()
+ *                                   ...
+ *                                   slots[0]: empty → full
+ *
+ * To reproduce this unlikely scenario, we must fill up the ready queue, then
+ * call ioq_cancel() which pushes an additional sentinel IOQ_STOP operation.
+ */
+static void check_ioq_push_block(void) {
+	// Must be a power of two to fill the entire queue
+	const size_t depth = 2;
+
+	struct ioq *ioq = ioq_create(depth, 1);
+	bfs_verify(ioq, "ioq_create(): %s", xstrerror(errno));
+
+	// Push enough operations to fill the queue
+	for (size_t i = 0; i < depth; ++i) {
+		struct bfs_dir *dir = bfs_allocdir();
+		bfs_verify(dir, "bfs_allocdir(): %s", xstrerror(errno));
+
+		int ret = ioq_opendir(ioq, dir, AT_FDCWD, ".", 0, NULL);
+		bfs_verify(ret == 0, "ioq_opendir(): %s", xstrerror(errno));
+	}
+	bfs_verify(ioq_capacity(ioq) == 0);
+
+	// Now cancel the queue, pushing an additional IOQ_STOP message
+	ioq_cancel(ioq);
+
+	// Drain the queue
+	for (size_t i = 0; i < depth; ++i) {
+		struct ioq_ent *ent = ioq_pop(ioq, true);
+		bfs_verify(ent && ent->op == IOQ_OPENDIR);
+
+		if (ent->result >= 0) {
+			bfs_closedir(ent->opendir.dir);
+		}
+		free(ent->opendir.dir);
+		ioq_free(ioq, ent);
+	}
+	bfs_verify(!ioq_pop(ioq, true));
+
+	ioq_destroy(ioq);
+}
+
+bool check_ioq(void) {
+	check_ioq_push_block();
+	return true;
+}
diff --git a/tests/ls-color.sh b/tests/ls-color.sh
index c82a58d..b9a0402 100755
--- a/tests/ls-color.sh
+++ b/tests/ls-color.sh
@@ -1,36 +1,50 @@
 #!/usr/bin/env bash
 
-############################################################################
-# bfs                                                                      #
-# Copyright (C) 2019 Tavian Barnes <tavianator@tavianator.com>             #
-#                                                                          #
-# Permission to use, copy, modify, and/or distribute this software for any #
-# purpose with or without fee is hereby granted.                           #
-#                                                                          #
-# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES #
-# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF         #
-# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR  #
-# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES   #
-# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN    #
-# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF  #
-# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.           #
-############################################################################
+# Copyright © Tavian Barnes <tavianator@tavianator.com>
+# SPDX-License-Identifier: 0BSD
 
 # Prints the "ground truth" coloring of a path using ls
 
 set -e
 
+parse_ls_colors() {
+    for key; do
+        local -n var="$key"
+        if [[ "$LS_COLORS" =~ (^|:)$key=(([^:]|\\:)*) ]]; then
+            var="${BASH_REMATCH[2]}"
+            # Interpret escapes
+            var=$(printf "$var" | sed $'s/\^\[/\033/g; s/\\\\:/:/g')
+        fi
+    done
+}
+
+re_escape() {
+    # https://stackoverflow.com/a/29613573/502399
+    sed 's/[^^]/[&]/g; s/\^/\\^/g' <<<"$1"
+}
+
+rs=0
+lc=$'\033['
+rc=m
+ec=
+no=
+
+parse_ls_colors rs lc rc ec no
+: "${ec:=$lc$rs$rc}"
+
+strip="(($(re_escape "$lc$no$rc"))?($(re_escape "$ec")|$(re_escape "$lc$rc")))+"
+
+ls_color() {
+    # Strip the leading reset sequence from the ls output
+    ls -1d --color "$@" | sed -E "s/^$strip([a-z].*)$strip/\4/; s/^$strip//"
+}
+
 L=
 if [ "$1" = "-L" ]; then
     L="$1"
     shift
 fi
 
-function ls_color() {
-    # Strip the leading reset sequence from the ls output
-    ls -1d --color "$@" | sed $'s/^\033\\[0m//'
-}
-
 DIR="${1%/*}"
 if [ "$DIR" = "$1" ]; then
     ls_color "$1"
diff --git a/tests/main.c b/tests/main.c
new file mode 100644
index 0000000..429772b
--- /dev/null
+++ b/tests/main.c
@@ -0,0 +1,125 @@
+// Copyright © Tavian Barnes <tavianator@tavianator.com>
+// SPDX-License-Identifier: 0BSD
+
+/**
+ * Entry point for unit tests.
+ */
+
+#include "prelude.h"
+#include "tests.h"
+#include "bfstd.h"
+#include "color.h"
+#include <errno.h>
+#include <locale.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+
+/**
+ * Test context.
+ */
+struct test_ctx {
+	/** Number of command line arguments. */
+	int argc;
+	/** The arguments themselves. */
+	char **argv;
+
+	/** Parsed colors. */
+	struct colors *colors;
+	/** Colorized output stream. */
+	CFILE *cout;
+
+	/** Eventual exit status. */
+	int ret;
+};
+
+/** Initialize the test context. */
+static int test_init(struct test_ctx *ctx, int argc, char **argv) {
+	ctx->argc = argc;
+	ctx->argv = argv;
+
+	ctx->colors = parse_colors();
+	ctx->cout = cfwrap(stdout, ctx->colors, false);
+	if (!ctx->cout) {
+		ctx->ret = EXIT_FAILURE;
+		return -1;
+	}
+
+	ctx->ret = EXIT_SUCCESS;
+	return 0;
+}
+
+/** Finalize the test context. */
+static int test_fini(struct test_ctx *ctx) {
+	if (ctx->cout) {
+		cfclose(ctx->cout);
+	}
+
+	free_colors(ctx->colors);
+
+	return ctx->ret;
+}
+
+/** Check if a test case is enabled for this run. */
+static bool should_run(const struct test_ctx *ctx, const char *test) {
+	// Run all tests by default
+	if (ctx->argc < 2) {
+		return true;
+	}
+
+	// With args, run only specified tests
+	for (int i = 1; i < ctx->argc; ++i) {
+		if (strcmp(test, ctx->argv[i]) == 0) {
+			return true;
+		}
+	}
+
+	return false;
+}
+
+/** Run a test if it's enabled. */
+static void run_test(struct test_ctx *ctx, const char *test, test_fn *fn) {
+	if (should_run(ctx, test)) {
+		if (fn()) {
+			cfprintf(ctx->cout, "${grn}[PASS]${rs} ${bld}%s${rs}\n", test);
+		} else {
+			cfprintf(ctx->cout, "${red}[FAIL]${rs} ${bld}%s${rs}\n", test);
+			ctx->ret = EXIT_FAILURE;
+		}
+	}
+}
+
+const char *bfs_errstr(void) {
+	return xstrerror(errno);
+}
+
+int main(int argc, char *argv[]) {
+	// Try to set a UTF-8 locale
+	if (!setlocale(LC_ALL, "C.UTF-8")) {
+		setlocale(LC_ALL, "");
+	}
+
+	// Run tests in UTC
+	if (setenv("TZ", "UTC0", true) != 0) {
+		perror("setenv()");
+		return EXIT_FAILURE;
+	}
+	tzset();
+
+	struct test_ctx ctx;
+	if (test_init(&ctx, argc, argv) != 0) {
+		goto done;
+	}
+
+	run_test(&ctx, "alloc", check_alloc);
+	run_test(&ctx, "bfstd", check_bfstd);
+	run_test(&ctx, "bit", check_bit);
+	run_test(&ctx, "ioq", check_ioq);
+	run_test(&ctx, "trie", check_trie);
+	run_test(&ctx, "xspawn", check_xspawn);
+	run_test(&ctx, "xtime", check_xtime);
+
+done:
+	return test_fini(&ctx);
+}
diff --git a/tests/mksock.c b/tests/mksock.c
index d1776b3..5786cb6 100644
--- a/tests/mksock.c
+++ b/tests/mksock.c
@@ -1,29 +1,16 @@
-/****************************************************************************
- * bfs                                                                      *
- * Copyright (C) 2019 Tavian Barnes <tavianator@tavianator.com>             *
- *                                                                          *
- * Permission to use, copy, modify, and/or distribute this software for any *
- * purpose with or without fee is hereby granted.                           *
- *                                                                          *
- * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES *
- * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF         *
- * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR  *
- * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES   *
- * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN    *
- * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF  *
- * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.           *
- ****************************************************************************/
+// Copyright © Tavian Barnes <tavianator@tavianator.com>
+// SPDX-License-Identifier: 0BSD
 
 /**
  * There's no standard Unix utility that creates a socket file, so this small
  * program does the job.
  */
 
+#include "bfstd.h"
 #include <errno.h>
-#include <libgen.h>
 #include <stdio.h>
-#include <string.h>
 #include <stdlib.h>
+#include <string.h>
 #include <sys/socket.h>
 #include <sys/un.h>
 #include <unistd.h>
@@ -32,7 +19,7 @@
  * Print an error message.
  */
 static void errmsg(const char *cmd, const char *path) {
-	fprintf(stderr, "%s: '%s': %s.\n", cmd, path, strerror(errno));
+	fprintf(stderr, "%s: '%s': %s.\n", cmd, path, xstrerror(errno));
 }
 
 /**
@@ -41,18 +28,13 @@ static void errmsg(const char *cmd, const char *path) {
  * file name is not.
  */
 static int chdir_parent(const char *path) {
-	char *copy = strdup(path);
-	if (!copy) {
+	char *dir = xdirname(path);
+	if (!dir) {
 		return -1;
 	}
-	const char *dir = dirname(copy);
 
 	int ret = chdir(dir);
-
-	int error = errno;
-	free(copy);
-	errno = error;
-
+	free(dir);
 	return ret;
 }
 
@@ -66,22 +48,21 @@ static int init_sun(struct sockaddr_un *sock, const char *path) {
 		return -1;
 	}
 
-	char *copy = strdup(path);
-	if (!copy) {
+	char *base = xbasename(path);
+	if (!base) {
 		return -1;
 	}
-	const char *base = basename(copy);
 
 	len = strlen(base);
 	if (len >= sizeof(sock->sun_path)) {
-		free(copy);
+		free(base);
 		errno = ENAMETOOLONG;
 		return -1;
 	}
 
 	sock->sun_family = AF_UNIX;
 	memcpy(sock->sun_path, base, len + 1);
-	free(copy);
+	free(base);
 	return 0;
 }
 
@@ -119,7 +100,7 @@ int main(int argc, char *argv[]) {
 		ret = EXIT_FAILURE;
 	}
 
-	if (close(fd) != 0) {
+	if (xclose(fd) != 0) {
 		errmsg(cmd, path);
 		ret = EXIT_FAILURE;
 	}
diff --git a/tests/posix/L_loops.sh b/tests/posix/L_loops.sh
index f737cea..01b7efc 100644
--- a/tests/posix/L_loops.sh
+++ b/tests/posix/L_loops.sh
@@ -1,4 +1,4 @@
 # POSIX says it's okay to either stop or keep going on seeing a filesystem
 # loop, as long as a diagnostic is printed
-errors=$(invoke_bfs -L loops 2>&1 >/dev/null)
-[ -n "$errors" ]
+invoke_bfs -L loops >/dev/null 2>"$OUT" && fail
+test -s "$OUT"
diff --git a/tests/posix/L_xdev.out b/tests/posix/L_xdev.out
index 2e80082..788579d 100644
--- a/tests/posix/L_xdev.out
+++ b/tests/posix/L_xdev.out
@@ -1,5 +1,5 @@
-scratch
-scratch/foo
-scratch/foo/bar
-scratch/foo/qux
-scratch/mnt
+.
+./foo
+./foo/bar
+./foo/qux
+./mnt
diff --git a/tests/posix/L_xdev.sh b/tests/posix/L_xdev.sh
index ddbadd8..82d8605 100644
--- a/tests/posix/L_xdev.sh
+++ b/tests/posix/L_xdev.sh
@@ -1,15 +1,13 @@
-skip_unless test "$SUDO"
-skip_if test "$UNAME" = "Darwin"
+test "$UNAME" = "Darwin" && skip
 
-clean_scratch
-mkdir scratch/{foo,mnt}
-sudo mount -t tmpfs tmpfs scratch/mnt
-ln -s ../mnt scratch/foo/bar
-"$XTOUCH" scratch/mnt/baz
-ln -s ../mnt/baz scratch/foo/qux
+cd "$TEST"
+mkdir foo mnt
 
-bfs_diff -L scratch -xdev
-ret=$?
+bfs_sudo mount -t tmpfs tmpfs mnt || skip
+defer bfs_sudo umount mnt
 
-sudo umount scratch/mnt
-return $ret
+ln -s ../mnt foo/bar
+"$XTOUCH" mnt/baz
+ln -s ../mnt/baz foo/qux
+
+bfs_diff -L . -xdev
diff --git a/tests/posix/closed_stderr.sh b/tests/posix/closed_stderr.sh
deleted file mode 100644
index cc746ef..0000000
--- a/tests/posix/closed_stderr.sh
+++ /dev/null
@@ -1 +0,0 @@
-fail invoke_bfs basic >&- 2>&-
diff --git a/tests/posix/closed_stdout.sh b/tests/posix/closed_stdout.sh
deleted file mode 100644
index 446bf56..0000000
--- a/tests/posix/closed_stdout.sh
+++ /dev/null
@@ -1 +0,0 @@
-fail invoke_bfs basic >&-
diff --git a/tests/posix/deep.sh b/tests/posix/deep.sh
index 3d1cd60..36a88c0 100644
--- a/tests/posix/deep.sh
+++ b/tests/posix/deep.sh
@@ -1,4 +1,2 @@
-closefrom 4
-
-ulimit -n 16
+ulimit -n $((NOPENFD + 13))
 bfs_diff deep -type f -exec bash -c 'echo "${1:0:6}/.../${1##*/} (${#1})"' bash {} \;
diff --git a/tests/posix/depth_error.out b/tests/posix/depth_error.out
index ed0e9a1..7ed5f0d 100644
--- a/tests/posix/depth_error.out
+++ b/tests/posix/depth_error.out
@@ -1,2 +1,2 @@
-scratch
-scratch/foo
+.
+./foo
diff --git a/tests/posix/depth_error.sh b/tests/posix/depth_error.sh
index f770210..db414ba 100644
--- a/tests/posix/depth_error.sh
+++ b/tests/posix/depth_error.sh
@@ -1,11 +1,7 @@
-clean_scratch
-"$XTOUCH" -p scratch/foo/bar
-chmod a-r scratch/foo
+cd "$TEST"
+"$XTOUCH" -p foo/bar
 
-bfs_diff scratch -depth
-ret=$?
+chmod a-r foo
+defer chmod +r foo
 
-chmod +r scratch/foo
-clean_scratch
-
-[ $ret -eq $EX_BFS ]
+! bfs_diff . -depth
diff --git a/tests/posix/exec_nonexistent.sh b/tests/posix/exec_nonexistent.sh
index b4e08e0..a9ff052 100644
--- a/tests/posix/exec_nonexistent.sh
+++ b/tests/posix/exec_nonexistent.sh
@@ -1,8 +1,4 @@
 # Failure to execute the command should lead to an error message and
 # non-zero exit status.  See https://unix.stackexchange.com/q/704522/56202
-
-stderr=$(invoke_bfs basic -exec "$TESTS/nonexistent" {} \; 2>&1 >/dev/null)
-[ -n "$stderr" ] || return 1
-
-bfs_diff basic -print -exec "$TESTS/nonexistent" {} \; -print
-(($? == EX_BFS))
+bfs_diff basic -print -exec "$TESTS/nonexistent" {} \; -print 2>"$TEST/err" && fail
+test -s "$TEST/err"
diff --git a/tests/posix/exec_plus_nonexistent.sh b/tests/posix/exec_plus_nonexistent.sh
index f96099e..24582a3 100644
--- a/tests/posix/exec_plus_nonexistent.sh
+++ b/tests/posix/exec_plus_nonexistent.sh
@@ -1,5 +1,2 @@
-stderr=$(invoke_bfs basic -exec "$TESTS/nonexistent" {} + 2>&1 >/dev/null)
-[ -n "$stderr" ] || return 1
-
-bfs_diff basic -exec "$TESTS/nonexistent" {} + -print
-(($? == EX_BFS))
+bfs_diff basic -exec "$TESTS/nonexistent" {} + -print 2>"$TEST/err" && fail
+test -s "$TEST/err"
diff --git a/tests/posix/exec_plus_nothing.sh b/tests/posix/exec_plus_nothing.sh
index ef01968..347722d 100644
--- a/tests/posix/exec_plus_nothing.sh
+++ b/tests/posix/exec_plus_nothing.sh
@@ -1,2 +1,2 @@
 # Regression test: don't look OOB for {} +
-fail invoke_bfs basic -exec +
+! invoke_bfs basic -exec +
diff --git a/tests/posix/exec_plus_status.sh b/tests/posix/exec_plus_status.sh
index ea9e5ef..a814c4e 100644
--- a/tests/posix/exec_plus_status.sh
+++ b/tests/posix/exec_plus_status.sh
@@ -1,4 +1,3 @@
 # -exec ... {} + should always return true, but if the command fails, bfs
 # should exit with a non-zero status
-bfs_diff basic -exec false {} + -print
-(($? == EX_BFS))
+! bfs_diff basic -exec false {} + -print
diff --git a/tests/posix/exec_ulimit.out b/tests/posix/exec_ulimit.out
new file mode 100644
index 0000000..144169e
--- /dev/null
+++ b/tests/posix/exec_ulimit.out
@@ -0,0 +1,16 @@
+64 deep/0/.../0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+64 deep/1/.../0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+64 deep/2/.../0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+64 deep/3/.../0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+64 deep/4/.../0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+64 deep/5/.../0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+64 deep/6/.../0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+64 deep/7/.../0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+64 deep/8/.../0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+64 deep/9/.../0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+64 deep/A/.../0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+64 deep/B/.../0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+64 deep/C/.../0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+64 deep/D/.../0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+64 deep/E/.../0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
+64 deep/F/.../0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDE
diff --git a/tests/posix/exec_ulimit.sh b/tests/posix/exec_ulimit.sh
new file mode 100644
index 0000000..655fbec
--- /dev/null
+++ b/tests/posix/exec_ulimit.sh
@@ -0,0 +1,2 @@
+ulimit -Sn 64
+bfs_diff deep -type f -exec bash -c 'printf "%d %s\n" $(ulimit -Sn) "${1:0:6}/.../${1##*/}"' bash {} \;
diff --git a/tests/posix/extra_paren.sh b/tests/posix/extra_paren.sh
index cd8e8f8..d15022f 100644
--- a/tests/posix/extra_paren.sh
+++ b/tests/posix/extra_paren.sh
@@ -1 +1 @@
-fail invoke_bfs basic -print \)
+! invoke_bfs basic -print \)
diff --git a/tests/posix/incomplete.sh b/tests/posix/incomplete.sh
index 07b1b61..bca5a13 100644
--- a/tests/posix/incomplete.sh
+++ b/tests/posix/incomplete.sh
@@ -1 +1 @@
-fail invoke_bfs basic \(
+! invoke_bfs basic \(
diff --git a/tests/posix/missing_paren.sh b/tests/posix/missing_paren.sh
index ac8dd60..d906fbe 100644
--- a/tests/posix/missing_paren.sh
+++ b/tests/posix/missing_paren.sh
@@ -1 +1 @@
-fail invoke_bfs basic \( -print
+! invoke_bfs basic \( -print
diff --git a/tests/posix/name_bracket.sh b/tests/posix/name_bracket.sh
index 84a417f..e2f943d 100644
--- a/tests/posix/name_bracket.sh
+++ b/tests/posix/name_bracket.sh
@@ -1,5 +1,9 @@
-# fnmatch() is broken on macOS
-skip_if test "$UNAME" = "Darwin"
+# fnmatch() is broken on some platforms
+case "$UNAME" in
+    Darwin|NetBSD)
+        skip
+        ;;
+esac
 
 # An unclosed [ should be matched literally
 bfs_diff weirdnames -name '['
diff --git a/tests/posix/newer_broken.out b/tests/posix/newer_broken.out
new file mode 100644
index 0000000..d2dcdd1
--- /dev/null
+++ b/tests/posix/newer_broken.out
@@ -0,0 +1 @@
+times
diff --git a/tests/posix/newer_broken.sh b/tests/posix/newer_broken.sh
new file mode 100644
index 0000000..dccaa73
--- /dev/null
+++ b/tests/posix/newer_broken.sh
@@ -0,0 +1,4 @@
+ln -s nowhere "$TEST/broken"
+"$XTOUCH" -h -t "1991-12-14 00:03" "$TEST/broken"
+
+bfs_diff times -newer "$TEST/broken"
diff --git a/tests/posix/newer_nonexistent.sh b/tests/posix/newer_nonexistent.sh
index 789cadf..5f2da4b 100644
--- a/tests/posix/newer_nonexistent.sh
+++ b/tests/posix/newer_nonexistent.sh
@@ -1 +1 @@
-fail invoke_bfs times -newer times/nonexistent
+! invoke_bfs times -newer times/nonexistent
diff --git a/tests/posix/nogroup_ulimit.sh b/tests/posix/nogroup_ulimit.sh
index 8f758c4..a39dd1f 100644
--- a/tests/posix/nogroup_ulimit.sh
+++ b/tests/posix/nogroup_ulimit.sh
@@ -1,8 +1,2 @@
-closefrom 4
-ulimit -n 16
-
-# -mindepth 18, but POSIX
-path="*/*/*/*/*/*"
-path="$path/$path/$path"
-bfs_diff deep -path "deep/$path" -nogroup
-
+ulimit -n $((NOPENFD + 13))
+bfs_diff deep -type f -nogroup
diff --git a/tests/posix/nouser_ulimit.sh b/tests/posix/nouser_ulimit.sh
index 2777589..a94b8c5 100644
--- a/tests/posix/nouser_ulimit.sh
+++ b/tests/posix/nouser_ulimit.sh
@@ -1,7 +1,2 @@
-closefrom 4
-ulimit -n 16
-
-# -mindepth 18, but POSIX
-path="*/*/*/*/*/*"
-path="$path/$path/$path"
-bfs_diff deep -path "deep/$path" -nouser
+ulimit -n $((NOPENFD + 13))
+bfs_diff deep -type f -nouser
diff --git a/tests/posix/ok_plus_nothing.sh b/tests/posix/ok_plus_nothing.sh
index 7cb7de5..77c7644 100644
--- a/tests/posix/ok_plus_nothing.sh
+++ b/tests/posix/ok_plus_nothing.sh
@@ -1,2 +1,2 @@
 # Regression test: don't look OOB for {} +
-fail invoke_bfs basic -ok +
+! invoke_bfs basic -ok +
diff --git a/tests/posix/overlayfs.out b/tests/posix/overlayfs.out
new file mode 100644
index 0000000..b472b56
--- /dev/null
+++ b/tests/posix/overlayfs.out
@@ -0,0 +1,5 @@
+merged
+merged/bar
+merged/baz
+merged/baz/qux
+merged/foo
diff --git a/tests/posix/overlayfs.sh b/tests/posix/overlayfs.sh
new file mode 100644
index 0000000..21ef22f
--- /dev/null
+++ b/tests/posix/overlayfs.sh
@@ -0,0 +1,11 @@
+test "$UNAME" = "Linux" || skip
+
+cd "$TEST"
+"$XTOUCH" -p lower/{foo,bar,baz} upper/{bar,baz/qux}
+
+mkdir -p work merged
+bfs_sudo mount -t overlay overlay -olowerdir=lower,upperdir=upper,workdir=work merged || skip
+defer bfs_sudo rm -rf work
+defer bfs_sudo umount merged
+
+bfs_diff merged
diff --git a/tests/posix/readdir_error.sh b/tests/posix/readdir_error.sh
new file mode 100644
index 0000000..82fcd17
--- /dev/null
+++ b/tests/posix/readdir_error.sh
@@ -0,0 +1,37 @@
+test "$UNAME" = "Linux" || skip
+
+cd "$TEST"
+mkfifo hang pid wait running
+
+(
+    # Create a zombie process
+    cat hang >/dev/null &
+    # Write the PID to pid
+    echo $! >pid
+    # Don't wait on the zombie process
+    exec cat wait hang >running
+) &
+
+# Kill the parent cat on exit
+defer kill -9 %1
+
+# Read the child PID
+read -r pid <pid
+
+# Make sure the parent cat is running before we kill the child, because bash
+# will wait() on its children
+echo >wait &
+read -r _ <running
+
+# Turn the child into a zombie
+kill -9 "$pid"
+
+# Wait until it's really a zombie
+state=R
+while [ "$state" != "Z" ]; do
+    read -r _ _ state _ <"/proc/$pid/stat"
+done
+
+# On Linux, open(/proc/$pid/net) will succeed but readdir() will fail
+test -r "/proc/$pid/net" || skip
+! invoke_bfs "/proc/$pid/net" >/dev/null
diff --git a/tests/posix/type_bind_mount.out b/tests/posix/type_bind_mount.out
index 6435159..2f06c47 100644
--- a/tests/posix/type_bind_mount.out
+++ b/tests/posix/type_bind_mount.out
@@ -1 +1 @@
-scratch/null
+./null
diff --git a/tests/posix/type_bind_mount.sh b/tests/posix/type_bind_mount.sh
index 445f6ef..97b7305 100644
--- a/tests/posix/type_bind_mount.sh
+++ b/tests/posix/type_bind_mount.sh
@@ -1,12 +1,9 @@
-skip_unless test "$SUDO"
-skip_unless test "$UNAME" = "Linux"
+test "$UNAME" = "Linux" || skip
 
-clean_scratch
-"$XTOUCH" scratch/{file,null}
-sudo mount --bind /dev/null scratch/null
+cd "$TEST"
+"$XTOUCH" file null
 
-bfs_diff scratch -type c
-ret=$?
+bfs_sudo mount --bind /dev/null null || skip
+defer bfs_sudo umount null
 
-sudo umount scratch/null
-return $ret
+bfs_diff . -type c
diff --git a/tests/posix/unionfs.out b/tests/posix/unionfs.out
new file mode 100644
index 0000000..28c4ec1
--- /dev/null
+++ b/tests/posix/unionfs.out
@@ -0,0 +1,10 @@
+.
+./lower
+./lower/bar
+./lower/baz
+./lower/foo
+./upper
+./upper/bar
+./upper/baz
+./upper/baz/qux
+./upper/foo
diff --git a/tests/posix/unionfs.sh b/tests/posix/unionfs.sh
new file mode 100644
index 0000000..94d3929
--- /dev/null
+++ b/tests/posix/unionfs.sh
@@ -0,0 +1,9 @@
+[[ "$UNAME" == *BSD* ]] || skip
+
+cd "$TEST"
+"$XTOUCH" -p lower/{foo,bar,baz} upper/{bar,baz/qux}
+
+bfs_sudo mount -t unionfs -o below lower upper || skip
+defer bfs_sudo umount upper
+
+bfs_diff .
diff --git a/tests/posix/xdev.out b/tests/posix/xdev.out
index f7839fb..6253434 100644
--- a/tests/posix/xdev.out
+++ b/tests/posix/xdev.out
@@ -1,4 +1,4 @@
-scratch
-scratch/foo
-scratch/foo/bar
-scratch/mnt
+.
+./foo
+./foo/bar
+./mnt
diff --git a/tests/posix/xdev.sh b/tests/posix/xdev.sh
index 4591940..c59c5c8 100644
--- a/tests/posix/xdev.sh
+++ b/tests/posix/xdev.sh
@@ -1,13 +1,11 @@
-skip_unless test "$SUDO"
-skip_if test "$UNAME" = "Darwin"
+test "$UNAME" = "Darwin" && skip
 
-clean_scratch
-mkdir scratch/{foo,mnt}
-sudo mount -t tmpfs tmpfs scratch/mnt
-"$XTOUCH" scratch/foo/bar scratch/mnt/baz
+cd "$TEST"
+mkdir foo mnt
 
-bfs_diff scratch -xdev
-ret=$?
+bfs_sudo mount -t tmpfs tmpfs mnt || skip
+defer bfs_sudo umount mnt
 
-sudo umount scratch/mnt
-return $ret
+"$XTOUCH" foo/bar mnt/baz
+
+bfs_diff . -xdev
diff --git a/tests/run.sh b/tests/run.sh
new file mode 100644
index 0000000..df3bd88
--- /dev/null
+++ b/tests/run.sh
@@ -0,0 +1,470 @@
+#!/hint/bash
+
+# Copyright © Tavian Barnes <tavianator@tavianator.com>
+# SPDX-License-Identifier: 0BSD
+
+## Running test cases
+
+# Beginning/end of line escape sequences
+BOL=$'\n'
+EOL=$'\n'
+
+# Update $EOL for the terminal size
+update_eol() {
+    # Bash gets $COLUMNS from stderr, so if it's redirected use tput instead
+    local cols="${COLUMNS-}"
+    if [ -z "$cols" ]; then
+        cols=$(tput cols 2>/dev/tty)
+    fi
+
+    # Put the cursor at the last column, then write a space so the next
+    # character will wrap
+    EOL=$'\e['"${cols}G "
+}
+
+# ERR trap for tests
+debug_err() {
+    local ret=$? line func file
+    callers | while read -r line func file; do
+        if [ "$func" = source ]; then
+            debug "$file" $line "${RED}error $ret${RST}" >&$DUPERR
+            break
+        fi
+    done
+}
+
+# Source a test
+source_test() (
+    set -eE
+    trap debug_err ERR
+
+    if ((${#MAKE[@]})); then
+        # Close the jobserver pipes
+        exec {READY_PIPE}<&- {DONE_PIPE}>&-
+    fi
+
+    cd "$TMP"
+    source "$@"
+)
+
+# Run a test
+run_test() {
+    if ((VERBOSE_ERRORS)); then
+        source_test "$1"
+    else
+        source_test "$1" 2>"$TMP/$TEST.err"
+    fi
+    ret=$?
+
+    if ((${#MAKE[@]})); then
+        # Write one byte to the done pipe
+        printf . >&$DONE_PIPE
+    fi
+
+    case $ret in
+        0)
+            if ((VERBOSE_TESTS)); then
+                color printf "${BOL}${GRN}[PASS]${RST} ${BLD}%s${RST}\n" "$TEST"
+            fi
+            ;;
+        $EX_SKIP)
+            if ((VERBOSE_SKIPPED || VERBOSE_TESTS)); then
+                color printf "${BOL}${CYN}[SKIP]${RST} ${BLD}%s${RST}\n" "$TEST"
+            fi
+            ;;
+        *)
+            if ((!VERBOSE_ERRORS)); then
+                cat "$TMP/$TEST.err" >&2
+            fi
+            color printf "${BOL}${RED}[FAIL]${RST} ${BLD}%s${RST}\n" "$TEST"
+            ;;
+    esac
+
+    return $ret
+}
+
+# Count the tests running in the background
+BG=0
+
+# Run a test in the background
+bg_test() {
+    run_test "$1" &
+    ((++BG))
+}
+
+# Reap a finished background test
+reap_test() {
+    ((BG--))
+
+    case "$1" in
+        0)
+            ((++passed))
+            ;;
+        $EX_SKIP)
+            ((++skipped))
+            ;;
+        *)
+            ((++failed))
+            ;;
+    esac
+}
+
+# Wait for a background test to finish
+wait_test() {
+    local pid
+    wait -n -ppid
+    ret=$?
+    if [ -z "${pid:-}" ]; then
+        debug "${BASH_SOURCE[0]}" $((LINENO - 3)) "${RED}error $ret${RST}" >&$DUPERR
+        exit 1
+    fi
+
+    reap_test $ret
+}
+
+# Wait until we're ready to run another test
+wait_ready() {
+    if ((${#MAKE[@]})); then
+        # We'd like to parse the output of jobs -n, but we can't run it in a
+        # subshell or we won't get the right output
+        jobs -n >"$TMP/jobs"
+        while read -r job status ret foo; do
+            case "$status" in
+                Done)
+                    reap_test 0
+                    ;;
+                Exit)
+                    reap_test $ret
+                    ;;
+            esac
+        done <"$TMP/jobs"
+
+        # Read one byte from the ready pipe
+        read -r -N1 -u$READY_PIPE
+    elif ((BG >= JOBS)); then
+        wait_test
+    fi
+}
+
+# Run make as a co-process to use its job control
+comake() {
+    coproc {
+        # We can't just use std{in,out}, due to
+        # https://www.gnu.org/software/make/manual/html_node/Parallel-Input.html
+        exec {DONE_PIPE}<&0 {READY_PIPE}>&1
+        exec "${MAKE[@]}" -s \
+             -f "$TESTS/tests.mk" \
+             DONE=$DONE_PIPE \
+             READY=$READY_PIPE \
+             "${!TEST_CASES[@]}" \
+             </dev/null >/dev/null
+    }
+
+    # coproc pipes aren't inherited by subshells, so dup them
+    exec {READY_PIPE}<&${COPROC[0]} {DONE_PIPE}>&${COPROC[1]}
+}
+
+# Run all the tests
+run_tests() {
+    if ((VERBOSE_TESTS)); then
+        BOL=''
+    elif ((COLOR_STDOUT)); then
+        # Carriage return + clear line
+        BOL=$'\r\e[K'
+
+        # Workaround for bash 4: checkwinsize is off by default.  We can turn it
+        # on, but we also have to explicitly trigger a foreground job to finish
+        # so that it will update the window size before we use $COLUMNS
+        shopt -s checkwinsize
+        (:)
+
+        update_eol
+        trap update_eol WINCH
+    fi
+
+    passed=0
+    failed=0
+    skipped=0
+    ran=0
+    total=${#TEST_CASES[@]}
+
+    if ((COLOR_STDOUT || VERBOSE_TESTS)); then
+        TEST_FMT="${BOL}${YLW}[%3d%%]${RST} ${BLD}%s${RST}${EOL}"
+    else
+        TEST_FMT="."
+    fi
+
+    if ((${#MAKE[@]})); then
+        comake
+    fi
+
+    # Turn off set -e (but turn it back on in run_test)
+    set +e
+
+    for TEST in "${TEST_CASES[@]}"; do
+        wait_ready
+        if ((STOP && failed > 0)); then
+            break
+        fi
+
+        percent=$((100 * ran / total))
+        color printf "$TEST_FMT" $percent "$TEST"
+
+        mkdir -p "$TMP/$TEST"
+        OUT="$TMP/$TEST.out"
+
+        bg_test "$TESTS/$TEST.sh"
+        ((++ran))
+    done
+
+    while ((BG > 0)); do
+        wait_test
+    done
+
+    printf "${BOL}"
+
+    if ((passed > 0)); then
+        color printf "${GRN}[PASS]${RST} ${BLD}%3d${RST} / ${BLD}%d${RST}\n" $passed $total
+    fi
+    if ((skipped > 0)); then
+        color printf "${CYN}[SKIP]${RST} ${BLD}%3d${RST} / ${BLD}%d${RST}\n" $skipped $total
+    fi
+    if ((failed > 0)); then
+        color printf "${RED}[FAIL]${RST} ${BLD}%3d${RST} / ${BLD}%d${RST}\n" $failed $total
+        exit 1
+    fi
+}
+
+## Utilities for the tests themselves
+
+# Default return value for failed tests
+EX_FAIL=1
+
+# Fail the current test
+fail() {
+    exit $EX_FAIL
+}
+
+# Return value when a test is skipped
+EX_SKIP=77
+
+# Skip the current test
+skip() {
+    if ((VERBOSE_SKIPPED)); then
+        caller | {
+            read -r line file
+            printf "${BOL}"
+            debug "$file" $line "" >&$DUPOUT
+        }
+    fi
+
+    exit $EX_SKIP
+}
+
+# Run a command and check its exit status
+check_exit() {
+    local expected="$1"
+    local actual=0
+    shift
+    "$@" || actual=$?
+    ((actual == expected))
+}
+
+# Run a command with sudo
+bfs_sudo() {
+    if ((${#SUDO[@]})); then
+        "${SUDO[@]}" "$@"
+    else
+        return 1
+    fi
+}
+
+# Get the inode number of a file
+inum() {
+    ls -id "$@" | awk '{ print $1 }'
+}
+
+# Set an ACL on a file
+set_acl() {
+    case "$UNAME" in
+        Darwin)
+            chmod +a "$(id -un) allow read,write" "$1"
+            ;;
+        FreeBSD)
+            if (($(getconf ACL_NFS4 "$1") > 0)); then
+                setfacl -m "u:$(id -un):rw::allow" "$1"
+            else
+                setfacl -m "u:$(id -un):rw" "$1"
+            fi
+            ;;
+        *)
+            setfacl -m "u:$(id -un):rw" "$1"
+            ;;
+    esac
+}
+
+# Print a bfs invocation for --verbose=commands
+bfs_verbose() {
+    if ((VERBOSE_COMMANDS)); then
+        (
+            # Close some fds to make room for the pipe,
+            # even with extremely low ulimit -n
+            exec >&- {DUPERR}>&-
+            exec >&$DUPOUT {DUPOUT}>&-
+            color bfs_verbose_impl "$@"
+        )
+    fi
+}
+
+bfs_verbose_impl() {
+    printf "${GRN}%q${RST}" "${BFS[0]}"
+    if ((${#BFS[@]} > 1)); then
+        printf " ${GRN}%q${RST}" "${BFS[@]:1}"
+    fi
+
+    local expr_started=0 color
+    for arg; do
+        case "$arg" in
+            -[A-Z]*|-[dsxf]|-j*)
+                color="${CYN}"
+                ;;
+            \(|!|-[ao]|-and|-or|-not|-exclude)
+                expr_started=1
+                color="${RED}"
+                ;;
+            \)|,)
+                if ((expr_started)); then
+                    color="${RED}"
+                else
+                    color="${MAG}"
+                fi
+                ;;
+            -?*)
+                expr_started=1
+                color="${BLU}"
+                ;;
+            *)
+                if ((expr_started)); then
+                    color="${BLD}"
+                else
+                    color="${MAG}"
+                fi
+                ;;
+        esac
+        printf " ${color}%q${RST}" "$arg"
+    done
+
+    printf '\n'
+}
+
+# Run the bfs we're testing
+invoke_bfs() {
+    skip
+    bfs_verbose "$@"
+
+    local ret=0
+    # Close the logging fds
+    "${BFS[@]}" "$@" {DUPOUT}>&- {DUPERR}>&- || ret=$?
+
+    # Allow bfs to fail, but not crash
+    if ((ret > 125)); then
+        exit $ret
+    else
+        return $ret
+    fi
+}
+
+if command -v unbuffer &>/dev/null; then
+    UNBUFFER=unbuffer
+elif command -v expect_unbuffer &>/dev/null; then
+    UNBUFFER=expect_unbuffer
+fi
+
+# Run bfs with a pseudo-terminal attached
+bfs_pty() {
+    test -n "${UNBUFFER:-}" || skip
+
+    bfs_verbose "$@"
+
+    local ret=0
+    "$UNBUFFER" bash -c 'stty cols 80 rows 24 && "$@" </dev/null' bash "${BFS[@]}" "$@" || ret=$?
+
+    if ((ret > 125)); then
+        exit $ret
+    else
+        return $ret
+    fi
+}
+
+# Create a directory tree with xattrs in scratch
+make_xattrs() {
+    cd "$TEST"
+
+    "$XTOUCH" normal xattr xattr_2
+    ln -s xattr link
+    ln -s normal xattr_link
+
+    case "$UNAME" in
+        Darwin)
+            xattr -w bfs_test true xattr \
+                && xattr -w bfs_test_2 true xattr_2 \
+                && xattr -s -w bfs_test true xattr_link
+            ;;
+        FreeBSD)
+            setextattr user bfs_test true xattr \
+                && setextattr user bfs_test_2 true xattr_2 \
+                && setextattr -h user bfs_test true xattr_link
+            ;;
+        *)
+            # Linux tmpfs doesn't support the user.* namespace, so we use the security.*
+            # namespace, which is writable by root and readable by others
+            bfs_sudo setfattr -n security.bfs_test xattr \
+                && bfs_sudo setfattr -n security.bfs_test_2 xattr_2 \
+                && bfs_sudo setfattr -h -n security.bfs_test xattr_link
+            ;;
+    esac
+}
+
+## Snapshot testing
+
+# Return value when a difference is detected
+EX_DIFF=20
+
+# Detect colored diff support
+if diff --color /dev/null /dev/null &>/dev/null; then
+    DIFF="diff --color"
+else
+    DIFF="diff"
+fi
+
+# Sort the output file
+sort_output() {
+    sort -o "$OUT" "$OUT"
+}
+
+# Diff against the expected output
+diff_output() {
+    local GOLD="$TESTS/$TEST.out"
+
+    if ((UPDATE)); then
+        cp "$OUT" "$GOLD"
+    elif ! cmp -s "$GOLD" "$OUT"; then
+        $DIFF -u "$GOLD" "$OUT" >&$DUPERR
+    fi
+}
+
+# Run bfs, and diff it against the expected output
+bfs_diff() {
+    local fd
+    if ! fd=$("${BFS[@]}" "$@"); then
+        skip
+    fi
+
+    local ret=0
+    eval "$fd" >"$OUT" || ret=$?
+    sed -i 's|/$||' "$OUT"
+    sort_output
+    diff_output || exit $EX_DIFF
+
+    return $ret
+}
diff --git a/tests/stddirs.sh b/tests/stddirs.sh
new file mode 100644
index 0000000..e08e6bf
--- /dev/null
+++ b/tests/stddirs.sh
@@ -0,0 +1,152 @@
+#!/hint/bash
+
+# Copyright © Tavian Barnes <tavianator@tavianator.com>
+# SPDX-License-Identifier: 0BSD
+
+## Standard directory trees for tests
+
+# Creates a simple file+directory structure for tests
+make_basic() {
+    "$XTOUCH" -p "$1"/{a,b,c/d,e/f,g/h/,i/}
+    "$XTOUCH" -p "$1"/{j/foo,k/foo/bar,l/foo/bar/baz}
+    echo baz >"$1/l/foo/bar/baz"
+}
+
+# Creates a file+directory structure with various permissions for tests
+make_perms() {
+    "$XTOUCH" -p -M000 "$1/0"
+    "$XTOUCH" -p -M444 "$1/r"
+    "$XTOUCH" -p -M222 "$1/w"
+    "$XTOUCH" -p -M644 "$1/rw"
+    "$XTOUCH" -p -M555 "$1/rx"
+    "$XTOUCH" -p -M311 "$1/wx"
+    "$XTOUCH" -p -M755 "$1/rwx"
+}
+
+# Creates a file+directory structure with various symbolic and hard links
+make_links() {
+    "$XTOUCH" -p "$1/file"
+    ln -s file "$1/symlink"
+    ln "$1/file" "$1/hardlink"
+    ln -s nowhere "$1/broken"
+    ln -s symlink/file "$1/notdir"
+    "$XTOUCH" -p "$1/deeply/nested"/{dir/,file}
+    ln -s file "$1/deeply/nested/link"
+    ln -s nowhere "$1/deeply/nested/broken"
+    ln -s deeply/nested "$1/skip"
+}
+
+# Creates a file+directory structure with symbolic link loops
+make_loops() {
+    "$XTOUCH" -p "$1/file"
+    ln -s file "$1/symlink"
+    ln -s nowhere "$1/broken"
+    ln -s symlink/file "$1/notdir"
+    ln -s loop "$1/loop"
+    mkdir -p "$1/deeply/nested/dir"
+    ln -s ../../deeply "$1/deeply/nested/loop"
+    ln -s deeply/nested/loop/nested "$1/skip"
+}
+
+# Creates a file+directory structure with varying timestamps
+make_times() {
+    "$XTOUCH" -p -t "1991-12-14 00:00" "$1/a"
+    "$XTOUCH" -p -t "1991-12-14 00:01" "$1/b"
+    "$XTOUCH" -p -t "1991-12-14 00:02" "$1/c"
+    ln -s a "$1/l"
+    "$XTOUCH" -p -h -t "1991-12-14 00:03" "$1/l"
+    "$XTOUCH" -p -t "1991-12-14 00:04" "$1"
+}
+
+# Creates a file+directory structure with various weird file/directory names
+make_weirdnames() {
+    "$XTOUCH" -p "$1/-/a"
+    "$XTOUCH" -p "$1/(/b"
+    "$XTOUCH" -p "$1/(-/c"
+    "$XTOUCH" -p "$1/!/d"
+    "$XTOUCH" -p "$1/!-/e"
+    "$XTOUCH" -p "$1/,/f"
+    "$XTOUCH" -p "$1/)/g"
+    "$XTOUCH" -p "$1/.../h"
+    "$XTOUCH" -p "$1/\\/i"
+    "$XTOUCH" -p "$1/ /j"
+    "$XTOUCH" -p "$1/[/k"
+}
+
+# Creates a very deep directory structure for testing PATH_MAX handling
+make_deep() {
+    mkdir -p "$1"
+
+    # $name will be 255 characters, aka _XOPEN_NAME_MAX
+    local name="0123456789ABCDEF"
+    name="$name$name$name$name"
+    name="$name$name$name$name"
+    name="${name:0:255}"
+
+    # 4 * 4 * 256 == 4096 >= PATH_MAX
+    local path="$name/$name/$name/$name"
+    path="$path/$path/$path/$path"
+
+    "$XTOUCH" -p "$1"/{{0..9},A,B,C,D,E,F}/"$path/$name"
+}
+
+# Creates a directory structure with many different types, and therefore colors
+make_rainbow() {
+    "$XTOUCH" -p "$1/file.txt"
+    "$XTOUCH" -p "$1/file.dat"
+    "$XTOUCH" -p "$1/lower".{gz,tar,tar.gz}
+    "$XTOUCH" -p "$1/upper".{GZ,TAR,TAR.GZ}
+    "$XTOUCH" -p "$1/lu.tar.GZ" "$1/ul.TAR.gz"
+    ln -s file.txt "$1/link.txt"
+    "$XTOUCH" -p "$1/mh1"
+    ln "$1/mh1" "$1/mh2"
+    mkfifo "$1/pipe"
+    # TODO: block
+    ln -s /dev/null "$1/chardev_link"
+    ln -s nowhere "$1/broken"
+    "$MKSOCK" "$1/socket"
+    "$XTOUCH" -p "$1"/s{u,g,ug}id
+    chmod 06644 "$1"/sugid
+    chmod 04644 "$1"/suid
+    chmod 02644 "$1"/sgid
+    mkdir "$1/ow" "$1"/sticky{,_ow}
+    chmod o+w "$1"/*ow
+    chmod +t "$1"/sticky*
+    "$XTOUCH" -p "$1"/exec.sh
+    chmod +x "$1"/exec.sh
+    "$XTOUCH" -p "$1/"$'\e[1m/\e[0m'
+}
+
+# Create all standard directory trees
+make_stddirs() {
+    TMP=$(mktemp -d "${TMPDIR:-/tmp}"/bfs.XXXXXXXXXX)
+
+    if ((CLEAN)); then
+        defer clean_stddirs
+    else
+        printf "Test files saved to ${BLD}%s${RST}\n" "$TMP"
+    fi
+
+    chown "$(id -u):$(id -g)" "$TMP"
+
+    make_basic "$TMP/basic"
+    make_perms "$TMP/perms"
+    make_links "$TMP/links"
+    make_loops "$TMP/loops"
+    make_times "$TMP/times"
+    make_weirdnames "$TMP/weirdnames"
+    make_deep "$TMP/deep"
+    make_rainbow "$TMP/rainbow"
+}
+
+# Clean up temporary directories on exit
+clean_stddirs() {
+    # Don't force rm to deal with long paths
+    for dir in "$TMP"/deep/*/*; do
+        if [ -d "$dir" ]; then
+            (cd "$dir" && rm -rf *)
+        fi
+    done
+
+    rm -rf "$TMP"
+}
diff --git a/tests/tests.h b/tests/tests.h
new file mode 100644
index 0000000..9078938
--- /dev/null
+++ b/tests/tests.h
@@ -0,0 +1,73 @@
+// Copyright © Tavian Barnes <tavianator@tavianator.com>
+// SPDX-License-Identifier: 0BSD
+
+/**
+ * Unit tests.
+ */
+
+#ifndef BFS_TESTS_H
+#define BFS_TESTS_H
+
+#include "prelude.h"
+#include "diag.h"
+
+/** Unit test function type. */
+typedef bool test_fn(void);
+
+/** Memory allocation tests. */
+bool check_alloc(void);
+
+/** Standard library wrapper tests. */
+bool check_bfstd(void);
+
+/** Bit manipulation tests. */
+bool check_bit(void);
+
+/** I/O queue tests. */
+bool check_ioq(void);
+
+/** Trie tests. */
+bool check_trie(void);
+
+/** Process spawning tests. */
+bool check_xspawn(void);
+
+/** Time tests. */
+bool check_xtime(void);
+
+/** Don't ignore the bfs_check() return value. */
+attr(nodiscard)
+static inline bool bfs_check(bool ret) {
+	return ret;
+}
+
+/**
+ * Check a condition, logging a message on failure but continuing.
+ */
+#define bfs_check(...) \
+	bfs_check(bfs_check_(#__VA_ARGS__, __VA_ARGS__, "", ""))
+
+#define bfs_check_(str, cond, format, ...) \
+	((cond) ? true : (bfs_diag( \
+		sizeof(format) > 1 \
+			? "%.0s" format "%s%s" \
+			: "Check failed: `%s`%s", \
+		str, __VA_ARGS__), false))
+
+/** Get a string description of the last error. */
+const char *bfs_errstr(void);
+
+/**
+ * Check a condition, logging the current error string on failure.
+ */
+#define bfs_pcheck(...) \
+	bfs_pcheck_(#__VA_ARGS__, __VA_ARGS__, "", "")
+
+#define bfs_pcheck_(str, cond, format, ...) \
+	((cond) ? true : (bfs_diag( \
+		sizeof(format) > 1 \
+			? "%.0s" format "%s%s: %s" \
+			: "Check failed: `%s`%s: %s", \
+		str, __VA_ARGS__, bfs_errstr()), false))
+
+#endif // BFS_TESTS_H
diff --git a/tests/tests.mk b/tests/tests.mk
new file mode 100644
index 0000000..035ca79
--- /dev/null
+++ b/tests/tests.mk
@@ -0,0 +1,13 @@
+# Copyright © Tavian Barnes <tavianator@tavianator.com>
+# SPDX-License-Identifier: 0BSD
+
+# Makefile that exposes make's job control to tests.sh
+
+# BSD make will chdir into ${.OBJDIR} by default, unless we tell it not to
+.OBJDIR: .
+
+# Turn off implicit rules
+.SUFFIXES:
+
+.DEFAULT::
+	bash -c 'printf . >&$(READY) && read -r -N1 -u$(DONE)'
diff --git a/tests/tests.sh b/tests/tests.sh
index 762687e..3890243 100755
--- a/tests/tests.sh
+++ b/tests/tests.sh
@@ -1,711 +1,20 @@
 #!/usr/bin/env bash
 
-############################################################################
-# bfs                                                                      #
-# Copyright (C) 2015-2022 Tavian Barnes <tavianator@tavianator.com>        #
-#                                                                          #
-# Permission to use, copy, modify, and/or distribute this software for any #
-# purpose with or without fee is hereby granted.                           #
-#                                                                          #
-# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES #
-# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF         #
-# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR  #
-# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES   #
-# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN    #
-# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF  #
-# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.           #
-############################################################################
+# Copyright © Tavian Barnes <tavianator@tavianator.com>
+# SPDX-License-Identifier: 0BSD
 
 set -euP
 umask 022
 
-export LC_ALL=C
-export TZ=UTC0
-
-export ASAN_OPTIONS="abort_on_error=1"
-export LSAN_OPTIONS="abort_on_error=1"
-export MSAN_OPTIONS="abort_on_error=1"
-export TSAN_OPTIONS="abort_on_error=1"
-export UBSAN_OPTIONS="abort_on_error=1"
-
-export LS_COLORS=""
-unset BFS_COLORS
-
-if [ -t 1 ]; then
-    BLD=$'\033[01m'
-    RED=$'\033[01;31m'
-    GRN=$'\033[01;32m'
-    YLW=$'\033[01;33m'
-    BLU=$'\033[01;34m'
-    MAG=$'\033[01;35m'
-    CYN=$'\033[01;36m'
-    RST=$'\033[0m'
-else
-    BLD=
-    RED=
-    GRN=
-    YLW=
-    BLU=
-    MAG=
-    CYN=
-    RST=
-fi
-
-UNAME=$(uname)
-
-if command -v capsh &>/dev/null; then
-    if capsh --has-p=cap_dac_override &>/dev/null || capsh --has-p=cap_dac_read_search &>/dev/null; then
-	if [ -n "${BFS_TRIED_DROP:-}" ]; then
-            cat >&2 <<EOF
-${RED}error:${RST} Failed to drop capabilities.
-EOF
-
-	    exit 1
-	fi
-
-        cat >&2 <<EOF
-${YLW}warning:${RST} Running as ${BLD}$(id -un)${RST} is not recommended.  Dropping ${BLD}cap_dac_override${RST} and
-${BLD}cap_dac_read_search${RST}.
-
-EOF
-
-        BFS_TRIED_DROP=y exec capsh \
-            --drop=cap_dac_override,cap_dac_read_search \
-            --caps=cap_dac_override,cap_dac_read_search-eip \
-            -- "$0" "$@"
-    fi
-elif [ "$EUID" -eq 0 ]; then
-    UNLESS=
-    if [ "$UNAME" = "Linux" ]; then
-	UNLESS=" unless ${GRN}capsh${RST} is installed"
-    fi
-
-    cat >&2 <<EOF
-${RED}error:${RST} These tests expect filesystem permissions to be enforced, and therefore
-will not work when run as ${BLD}$(id -un)${RST}${UNLESS}.
-EOF
-    exit 1
-fi
-
-function usage() {
-    local pad=$(printf "%*s" ${#0} "")
-    cat <<EOF
-Usage: ${GRN}$0${RST} [${BLU}--bfs${RST}=${MAG}path/to/bfs${RST}] [${BLU}--posix${RST}] [${BLU}--bsd${RST}] [${BLU}--gnu${RST}] [${BLU}--all${RST}] [${BLU}--sudo${RST}]
-       $pad [${BLU}--stop${RST}] [${BLU}--noclean${RST}] [${BLU}--update${RST}] [${BLU}--verbose${RST}[=${BLD}LEVEL${RST}]] [${BLU}--help${RST}]
-       $pad [${BLD}TEST${RST} [${BLD}TEST${RST} ...]]
-
-  ${BLU}--bfs${RST}=${MAG}path/to/bfs${RST}
-      Set the path to the bfs executable to test (default: ${MAG}./bin/bfs${RST})
-
-  ${BLU}--posix${RST}, ${BLU}--bsd${RST}, ${BLU}--gnu${RST}, ${BLU}--all${RST}
-      Choose which test cases to run (default: ${BLU}--all${RST})
-
-  ${BLU}--sudo${RST}
-      Run tests that require root
-
-  ${BLU}--stop${RST}
-      Stop when the first error occurs
-
-  ${BLU}--noclean${RST}
-      Keep the test directories around after the run
-
-  ${BLU}--update${RST}
-      Update the expected outputs for the test cases
-
-  ${BLU}--verbose${RST}=${BLD}commands${RST}
-      Log the commands that get executed
-  ${BLU}--verbose${RST}=${BLD}errors${RST}
-      Don't redirect standard error
-  ${BLU}--verbose${RST}=${BLD}skipped${RST}
-      Log which tests get skipped
-  ${BLU}--verbose${RST}=${BLD}tests${RST}
-      Log all tests that get run
-  ${BLU}--verbose${RST}
-      Log everything
-
-  ${BLU}--help${RST}
-      This message
-
-  ${BLD}TEST${RST}
-      Select individual test cases to run (e.g. ${BLD}posix/basic${RST})
-EOF
-}
-
-DEFAULT=yes
-POSIX=
-COMMON=
-BSD=
-GNU=
-ALL=
-SUDO=
-STOP=
-CLEAN=yes
-UPDATE=
-VERBOSE_COMMANDS=
-VERBOSE_ERRORS=
-VERBOSE_SKIPPED=
-VERBOSE_TESTS=
-EXPLICIT=
-
-enabled_tests=()
-
-for arg; do
-    case "$arg" in
-        --bfs=*)
-            BFS="${arg#*=}"
-            ;;
-        --posix)
-            DEFAULT=
-            POSIX=yes
-            ;;
-        --bsd)
-            DEFAULT=
-            POSIX=yes
-            COMMON=yes
-            BSD=yes
-            ;;
-        --gnu)
-            DEFAULT=
-            POSIX=yes
-            COMMON=yes
-            GNU=yes
-            ;;
-        --all)
-            DEFAULT=
-            POSIX=yes
-            COMMON=yes
-            BSD=yes
-            GNU=yes
-            ALL=yes
-            ;;
-        --sudo)
-            SUDO=yes
-            ;;
-        --stop)
-            STOP=yes
-            ;;
-        --noclean)
-            CLEAN=
-            ;;
-        --update)
-            UPDATE=yes
-            ;;
-        --verbose=commands)
-            VERBOSE_COMMANDS=yes
-            ;;
-        --verbose=errors)
-            VERBOSE_ERRORS=yes
-            ;;
-        --verbose=skipped)
-            VERBOSE_SKIPPED=yes
-            ;;
-        --verbose=tests)
-            VERBOSE_SKIPPED=yes
-            VERBOSE_TESTS=yes
-            ;;
-        --verbose)
-            VERBOSE_COMMANDS=yes
-            VERBOSE_ERRORS=yes
-            VERBOSE_SKIPPED=yes
-            VERBOSE_TESTS=yes
-            ;;
-        --help)
-            usage
-            exit 0
-            ;;
-        */*)
-            EXPLICIT=yes
-            SUDO=yes
-            enabled_tests+=("$arg")
-            ;;
-        *)
-            printf "${RED}error:${RST} Unrecognized option '%s'.\n\n" "$arg" >&2
-            usage >&2
-            exit 1
-            ;;
-    esac
-done
-
-if [ "$DEFAULT" ]; then
-    POSIX=yes
-    COMMON=yes
-    BSD=yes
-    GNU=yes
-    ALL=yes
-fi
-
-function _realpath() {
-    (
-        cd "$(dirname -- "$1")"
-        echo "$PWD/$(basename -- "$1")"
-    )
-}
-
-TESTS=$(_realpath "$(dirname -- "${BASH_SOURCE[0]}")")
-
-if [ "${BUILDDIR-}" ]; then
-    BIN=$(_realpath "$BUILDDIR/bin")
-else
-    BIN=$(_realpath "$TESTS/../bin")
-fi
-MKSOCK="$BIN/tests/mksock"
-XTOUCH="$BIN/tests/xtouch"
-
-# Try to resolve the path to $BFS before we cd, while also supporting
-# --bfs="./bin/bfs -S ids"
-read -a BFS <<<"${BFS:-$BIN/find2fd}"
-BFS[0]=$(_realpath "$(command -v "${BFS[0]}")")
-
-# The temporary directory that will hold our test data
-TMP=$(mktemp -d "${TMPDIR:-/tmp}"/bfs.XXXXXXXXXX)
-chown "$(id -u):$(id -g)" "$TMP"
-
-cd "$TESTS"
-
-if [ ! "$EXPLICIT" ]; then
-    [ "$POSIX" ] && enabled_tests+=(posix/*.sh)
-    [ "$COMMON" ] && enabled_tests+=(common/*.sh)
-    [ "$BSD" ] && enabled_tests+=(bsd/*.sh)
-    [ "$GNU" ] && enabled_tests+=(gnu/*.sh)
-    [ "$ALL" ] && enabled_tests+=(bfs/*.sh)
-
-    enabled_tests=("${enabled_tests[@]%.sh}")
-fi
-
-function clean_scratch() {
-    if [ -e "$TMP/scratch" ]; then
-        # Try to unmount anything left behind
-        if [ "$SUDO" ] && command -v mountpoint &>/dev/null; then
-            for path in "$TMP"/scratch/*; do
-                if mountpoint -q "$path"; then
-                    sudo umount "$path"
-                fi
-            done
-        fi
-
-        # Reset any modified permissions
-        chmod -R +rX "$TMP/scratch"
-
-        rm -rf "$TMP/scratch"
-    fi
-
-    mkdir "$TMP/scratch"
-}
-
-# Clean up temporary directories on exit
-function cleanup() {
-    # Don't force rm to deal with long paths
-    for dir in "$TMP"/deep/*/*; do
-        if [ -d "$dir" ]; then
-            (cd "$dir" && rm -rf *)
-        fi
-    done
-
-    # In case a test left anything weird in scratch/
-    clean_scratch
-
-    rm -rf "$TMP"
-}
-
-if [ "$CLEAN" ]; then
-    trap cleanup EXIT
-else
-    echo "Test files saved to $TMP"
-fi
-
-# Creates a simple file+directory structure for tests
-function make_basic() {
-    "$XTOUCH" -p "$1"/{a,b,c/d,e/f,g/h/,i/}
-    "$XTOUCH" -p "$1"/{j/foo,k/foo/bar,l/foo/bar/baz}
-    echo baz >"$1/l/foo/bar/baz"
-}
-make_basic "$TMP/basic"
-
-# Creates a file+directory structure with various permissions for tests
-function make_perms() {
-    "$XTOUCH" -p -M000 "$1/0"
-    "$XTOUCH" -p -M444 "$1/r"
-    "$XTOUCH" -p -M222 "$1/w"
-    "$XTOUCH" -p -M644 "$1/rw"
-    "$XTOUCH" -p -M555 "$1/rx"
-    "$XTOUCH" -p -M311 "$1/wx"
-    "$XTOUCH" -p -M755 "$1/rwx"
-}
-make_perms "$TMP/perms"
-
-# Creates a file+directory structure with various symbolic and hard links
-function make_links() {
-    "$XTOUCH" -p "$1/file"
-    ln -s file "$1/symlink"
-    ln "$1/file" "$1/hardlink"
-    ln -s nowhere "$1/broken"
-    ln -s symlink/file "$1/notdir"
-    "$XTOUCH" -p "$1/deeply/nested"/{dir/,file}
-    ln -s file "$1/deeply/nested/link"
-    ln -s nowhere "$1/deeply/nested/broken"
-    ln -s deeply/nested "$1/skip"
-}
-make_links "$TMP/links"
-
-# Creates a file+directory structure with symbolic link loops
-function make_loops() {
-    "$XTOUCH" -p "$1/file"
-    ln -s file "$1/symlink"
-    ln -s nowhere "$1/broken"
-    ln -s symlink/file "$1/notdir"
-    ln -s loop "$1/loop"
-    mkdir -p "$1/deeply/nested/dir"
-    ln -s ../../deeply "$1/deeply/nested/loop"
-    ln -s deeply/nested/loop/nested "$1/skip"
-}
-make_loops "$TMP/loops"
-
-# Creates a file+directory structure with varying timestamps
-function make_times() {
-    "$XTOUCH" -p -t "1991-12-14 00:00" "$1/a"
-    "$XTOUCH" -p -t "1991-12-14 00:01" "$1/b"
-    "$XTOUCH" -p -t "1991-12-14 00:02" "$1/c"
-    ln -s a "$1/l"
-    "$XTOUCH" -p -h -t "1991-12-14 00:03" "$1/l"
-    "$XTOUCH" -p -t "1991-12-14 00:04" "$1"
-}
-make_times "$TMP/times"
-
-# Creates a file+directory structure with various weird file/directory names
-function make_weirdnames() {
-    "$XTOUCH" -p "$1/-/a"
-    "$XTOUCH" -p "$1/(/b"
-    "$XTOUCH" -p "$1/(-/c"
-    "$XTOUCH" -p "$1/!/d"
-    "$XTOUCH" -p "$1/!-/e"
-    "$XTOUCH" -p "$1/,/f"
-    "$XTOUCH" -p "$1/)/g"
-    "$XTOUCH" -p "$1/.../h"
-    "$XTOUCH" -p "$1/\\/i"
-    "$XTOUCH" -p "$1/ /j"
-    "$XTOUCH" -p "$1/[/k"
-}
-make_weirdnames "$TMP/weirdnames"
-
-# Creates a very deep directory structure for testing PATH_MAX handling
-function make_deep() {
-    mkdir -p "$1"
-
-    # $name will be 255 characters, aka _XOPEN_NAME_MAX
-    local name="0123456789ABCDEF"
-    name="${name}${name}${name}${name}"
-    name="${name}${name}${name}${name}"
-    name="${name:0:255}"
-
-    # 4 * 256 - 1 == 1023
-    local names="$name/$name/$name/$name"
-
-    for i in {0..9} A B C D E F; do
-        (
-            mkdir "$1/$i"
-            cd "$1/$i"
-
-            # 4 * 1024 == 4096 == PATH_MAX
-            for _ in {1..4}; do
-                mkdir -p "$names"
-                cd "$names"
-            done
-
-            "$XTOUCH" "$name"
-        )
-    done
-}
-make_deep "$TMP/deep"
-
-# Creates a directory structure with many different types, and therefore colors
-function make_rainbow() {
-    "$XTOUCH" -p "$1/file.txt"
-    "$XTOUCH" -p "$1/file.dat"
-    "$XTOUCH" -p "$1/star".{gz,tar,tar.gz}
-    ln -s file.txt "$1/link.txt"
-    "$XTOUCH" -p "$1/mh1"
-    ln "$1/mh1" "$1/mh2"
-    mkfifo "$1/pipe"
-    # TODO: block
-    ln -s /dev/null "$1/chardev_link"
-    ln -s nowhere "$1/broken"
-    "$MKSOCK" "$1/socket"
-    "$XTOUCH" -p "$1"/s{u,g,ug}id
-    chmod u+s "$1"/su{,g}id
-    chmod g+s "$1"/s{u,}gid
-    mkdir "$1/ow" "$1"/sticky{,_ow}
-    chmod o+w "$1"/*ow
-    chmod +t "$1"/sticky*
-    "$XTOUCH" -p "$1"/exec.sh
-    chmod +x "$1"/exec.sh
-}
-make_rainbow "$TMP/rainbow"
-
-# Close stdin so bfs doesn't think we're interactive
-exec </dev/null
-
-if [ "$VERBOSE_COMMANDS" ]; then
-    # dup stdout for verbose logging even when redirected
-    exec 3>&1
-fi
-
-function bfs_verbose() {
-    if [ "$VERBOSE_COMMANDS" ]; then
-        if [ -t 3 ]; then
-            printf "${GRN}%q${RST} " "${BFS[@]}" >&3
-
-            local expr_started=
-            for arg; do
-                if [[ $arg == -[A-Z]* ]]; then
-                    printf "${CYN}%q${RST} " "$arg" >&3
-                elif [[ $arg == [\(!] || $arg == -[ao] || $arg == -and || $arg == -or || $arg == -not ]]; then
-                    expr_started=yes
-                    printf "${RED}%q${RST} " "$arg" >&3
-                elif [[ $expr_started && $arg == [\),] ]]; then
-                    printf "${RED}%q${RST} " "$arg" >&3
-                elif [[ $arg == -?* ]]; then
-                    expr_started=yes
-                    printf "${BLU}%q${RST} " "$arg" >&3
-                elif [ "$expr_started" ]; then
-                    printf "${BLD}%q${RST} " "$arg" >&3
-                else
-                    printf "${MAG}%q${RST} " "$arg" >&3
-                fi
-            done
-        else
-            printf '%q ' "${BFS[@]}" "$@" >&3
-        fi
-        printf '\n' >&3
-    fi
-}
-
-function invoke_bfs() {
-    skip
-    bfs_verbose "$@"
-    "${BFS[@]}" "$@"
-}
-
-# Expect a command to fail, but not crash
-function fail() {
-    "$@"
-    local STATUS="$?"
-
-    if ((STATUS > 125)); then
-        exit "$STATUS"
-    elif ((STATUS > 0)); then
-        return 0
-    else
-        return 1
-    fi
-}
-
-# Detect colored diff support
-if [ -t 2 ] && diff --color=always /dev/null /dev/null 2>/dev/null; then
-    DIFF="diff --color=always"
-else
-    DIFF="diff"
-fi
-
-# Return value when bfs fails
-EX_BFS=10
-# Return value when a difference is detected
-EX_DIFF=20
-# Return value when a test is skipped
-EX_SKIP=77
-
-function sort_output() {
-    sort -o "$OUT" "$OUT"
-}
-
-function diff_output() {
-    local GOLD="$TESTS/$TEST.out"
-
-    if [ "$UPDATE" ]; then
-        cp "$OUT" "$GOLD"
-    else
-        $DIFF -u "$GOLD" "$OUT" >&2
-    fi
-}
-
-function bfs_diff() {
-    bfs_verbose "$@"
-
-    FD=$("${BFS[@]}" "$@")
-    if [ "$?" -ne 0 ]; then
-        skip
-    fi
-
-    eval "$FD" | sed 's|/$||' | sort >"$OUT"
-    local STATUS="${PIPESTATUS[0]}"
-    if [ "$STATUS" -ne 0 ]; then
-        skip
-    fi
-
-    diff_output || return $EX_DIFF
-
-    if [ "$STATUS" -eq 0 ]; then
-        return 0
-    else
-        return $EX_BFS
-    fi
-}
-
-function skip() {
-    exit $EX_SKIP
-}
-
-function skip_if() {
-    if "$@"; then
-        skip
-    fi
-}
-
-function skip_unless() {
-    skip_if fail "$@"
-}
-
-function closefrom() {
-    if [ -d /proc/self/fd ]; then
-        local fds=/proc/self/fd
-    else
-        local fds=/dev/fd
-    fi
-
-    for fd in "$fds"/*; do
-        if [ ! -e "$fd" ]; then
-            continue
-        fi
-
-        local fd="${fd##*/}"
-        if [ "$fd" -ge "$1" ]; then
-            eval "exec ${fd}<&-"
-        fi
-    done
-}
-
-function inum() {
-    ls -id "$@" | awk '{ print $1 }'
-}
-
-function set_acl() {
-    case "$UNAME" in
-        Darwin)
-            chmod +a "$(id -un) allow read,write" "$1"
-            ;;
-        FreeBSD)
-            if [ "$(getconf ACL_NFS4 "$1")" -gt 0 ]; then
-                setfacl -m "u:$(id -un):rw::allow" "$1"
-            else
-                setfacl -m "u:$(id -un):rw" "$1"
-            fi
-            ;;
-        *)
-            setfacl -m "u:$(id -un):rw" "$1"
-            ;;
-    esac
-}
-
-function make_xattrs() {
-    clean_scratch
-
-    "$XTOUCH" scratch/{normal,xattr,xattr_2}
-    ln -s xattr scratch/link
-    ln -s normal scratch/xattr_link
-
-    case "$UNAME" in
-        Darwin)
-            xattr -w bfs_test true scratch/xattr \
-                && xattr -w bfs_test_2 true scratch/xattr_2 \
-                && xattr -s -w bfs_test true scratch/xattr_link
-            ;;
-        FreeBSD)
-            setextattr user bfs_test true scratch/xattr \
-                && setextattr user bfs_test_2 true scratch/xattr_2 \
-                && setextattr -h user bfs_test true scratch/xattr_link
-            ;;
-        *)
-            # Linux tmpfs doesn't support the user.* namespace, so we use the security.*
-            # namespace, which is writable by root and readable by others
-            [ "$SUDO" ] \
-                && sudo setfattr -n security.bfs_test scratch/xattr \
-                && sudo setfattr -n security.bfs_test_2 scratch/xattr_2 \
-                && sudo setfattr -h -n security.bfs_test scratch/xattr_link
-            ;;
-    esac
-}
-
-cd "$TMP"
-set +e
-
-BOL='\n'
-EOL='\n'
-
-function update_eol() {
-    # Put the cursor at the last column, then write a space so the next
-    # character will wrap
-    EOL="\\033[${COLUMNS}G "
-}
-
-if [ "$VERBOSE_TESTS" ]; then
-    BOL=''
-elif [ -t 1 ]; then
-    BOL='\r\033[K'
-
-    # Workaround for bash 4: checkwinsize is off by default.  We can turn it on,
-    # but we also have to explicitly trigger a foreground job to finish so that
-    # it will update the window size before we use $COLUMNS
-    shopt -s checkwinsize
-    (:)
-
-    update_eol
-    trap update_eol WINCH
-fi
-
-passed=0
-failed=0
-skipped=0
-
-for TEST in "${enabled_tests[@]}"; do
-    if [[ -t 1 || "$VERBOSE_TESTS" ]]; then
-        printf "${BOL}${YLW}%s${RST}${EOL}" "$TEST"
-    else
-        printf "."
-    fi
-
-    OUT="$TMP/$TEST.out"
-    mkdir -p "${OUT%/*}"
-
-    if [ "$VERBOSE_ERRORS" ]; then
-        (. "$TESTS/$TEST.sh")
-    else
-        (. "$TESTS/$TEST.sh") 2>"$TMP/stderr"
-    fi
-    status=$?
-
-    if ((status == 0)); then
-        ((++passed))
-    elif ((status == EX_SKIP)); then
-        ((++skipped))
-        if [ "$VERBOSE_SKIPPED" ]; then
-            printf "${BOL}${CYN}%s skipped!${RST}\n" "$TEST"
-        fi
-    else
-        ((++failed))
-        [ "$VERBOSE_ERRORS" ] || cat "$TMP/stderr" >&2
-        printf "${BOL}${RED}%s failed!${RST}\n" "$TEST"
-        [ "$STOP" ] && break
-    fi
-done
-
-printf "${BOL}"
-
-if ((passed > 0)); then
-    printf "${GRN}tests passed: %d${RST}\n" "$passed"
-fi
-if ((skipped > 0)); then
-    printf "${CYN}tests skipped: %s${RST}\n" "$skipped"
-fi
-if ((failed > 0)); then
-    printf "${RED}tests failed: %s${RST}\n" "$failed"
-    exit 1
-fi
+TESTS="$(dirname -- "${BASH_SOURCE[0]}")"
+. "$TESTS/util.sh"
+. "$TESTS/color.sh"
+. "$TESTS/stddirs.sh"
+. "$TESTS/getopts.sh"
+. "$TESTS/run.sh"
+
+stdenv
+drop_root "$@"
+parse_args "$@"
+make_stddirs
+run_tests
diff --git a/tests/trie.c b/tests/trie.c
index 6bc7549..4667322 100644
--- a/tests/trie.c
+++ b/tests/trie.c
@@ -1,23 +1,10 @@
-/****************************************************************************
- * bfs                                                                      *
- * Copyright (C) 2020-2022 Tavian Barnes <tavianator@tavianator.com>        *
- *                                                                          *
- * Permission to use, copy, modify, and/or distribute this software for any *
- * purpose with or without fee is hereby granted.                           *
- *                                                                          *
- * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES *
- * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF         *
- * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR  *
- * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES   *
- * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN    *
- * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF  *
- * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.           *
- ****************************************************************************/
-
-#undef NDEBUG
-
-#include "../src/trie.h"
-#include <assert.h>
+// Copyright © Tavian Barnes <tavianator@tavianator.com>
+// SPDX-License-Identifier: 0BSD
+
+#include "prelude.h"
+#include "tests.h"
+#include "trie.h"
+#include "diag.h"
 #include <stdlib.h>
 #include <string.h>
 
@@ -50,14 +37,16 @@ const char *keys[] = {
 	">>>",
 };
 
-const size_t nkeys = sizeof(keys) / sizeof(keys[0]);
+const size_t nkeys = countof(keys);
+
+bool check_trie(void) {
+	bool ret = true;
 
-int main(void) {
 	struct trie trie;
 	trie_init(&trie);
 
 	for (size_t i = 0; i < nkeys; ++i) {
-		assert(!trie_find_str(&trie, keys[i]));
+		ret &= bfs_check(!trie_find_str(&trie, keys[i]));
 
 		const char *prefix = NULL;
 		for (size_t j = 0; j < i; ++j) {
@@ -70,38 +59,38 @@ int main(void) {
 
 		struct trie_leaf *leaf = trie_find_prefix(&trie, keys[i]);
 		if (prefix) {
-			assert(leaf);
-			assert(strcmp(prefix, leaf->key) == 0);
+			bfs_verify(leaf);
+			ret &= bfs_check(strcmp(prefix, leaf->key) == 0);
 		} else {
-			assert(!leaf);
+			ret &= bfs_check(!leaf);
 		}
 
 		leaf = trie_insert_str(&trie, keys[i]);
-		assert(leaf);
-		assert(strcmp(keys[i], leaf->key) == 0);
-		assert(leaf->length == strlen(keys[i]) + 1);
+		bfs_verify(leaf);
+		ret &= bfs_check(strcmp(keys[i], leaf->key) == 0);
+		ret &= bfs_check(leaf->length == strlen(keys[i]) + 1);
 	}
 
 	{
 		size_t i = 0;
-		TRIE_FOR_EACH(&trie, leaf) {
-			assert(leaf == trie_find_str(&trie, keys[i]));
-			assert(!leaf->prev || leaf->prev->next == leaf);
-			assert(!leaf->next || leaf->next->prev == leaf);
+		for_trie (leaf, &trie) {
+			ret &= bfs_check(leaf == trie_find_str(&trie, keys[i]));
+			ret &= bfs_check(!leaf->prev || leaf->prev->next == leaf);
+			ret &= bfs_check(!leaf->next || leaf->next->prev == leaf);
 			++i;
 		}
-		assert(i == nkeys);
+		ret &= bfs_check(i == nkeys);
 	}
 
 	for (size_t i = 0; i < nkeys; ++i) {
 		struct trie_leaf *leaf = trie_find_str(&trie, keys[i]);
-		assert(leaf);
-		assert(strcmp(keys[i], leaf->key) == 0);
-		assert(leaf->length == strlen(keys[i]) + 1);
+		bfs_verify(leaf);
+		ret &= bfs_check(strcmp(keys[i], leaf->key) == 0);
+		ret &= bfs_check(leaf->length == strlen(keys[i]) + 1);
 
 		trie_remove(&trie, leaf);
 		leaf = trie_find_str(&trie, keys[i]);
-		assert(!leaf);
+		ret &= bfs_check(!leaf);
 
 		const char *postfix = NULL;
 		for (size_t j = i + 1; j < nkeys; ++j) {
@@ -114,35 +103,35 @@ int main(void) {
 
 		leaf = trie_find_postfix(&trie, keys[i]);
 		if (postfix) {
-			assert(leaf);
-			assert(strcmp(postfix, leaf->key) == 0);
+			bfs_verify(leaf);
+			ret &= bfs_check(strcmp(postfix, leaf->key) == 0);
 		} else {
-			assert(!leaf);
+			ret &= bfs_check(!leaf);
 		}
 	}
 
-	TRIE_FOR_EACH(&trie, leaf) {
-		assert(false);
+	for_trie (leaf, &trie) {
+		ret &= bfs_check(false, "trie should be empty");
 	}
 
 	// This tests the "jump" node handling on 32-bit platforms
 	size_t longsize = 1 << 20;
 	char *longstr = malloc(longsize);
-	assert(longstr);
+	bfs_verify(longstr);
 
 	memset(longstr, 0xAC, longsize);
-	assert(!trie_find_mem(&trie, longstr, longsize));
-	assert(trie_insert_mem(&trie, longstr, longsize));
+	ret &= bfs_check(!trie_find_mem(&trie, longstr, longsize));
+	ret &= bfs_check(trie_insert_mem(&trie, longstr, longsize));
 
-	memset(longstr + longsize/2, 0xAB, longsize/2);
-	assert(!trie_find_mem(&trie, longstr, longsize));
-	assert(trie_insert_mem(&trie, longstr, longsize));
+	memset(longstr + longsize / 2, 0xAB, longsize / 2);
+	ret &= bfs_check(!trie_find_mem(&trie, longstr, longsize));
+	ret &= bfs_check(trie_insert_mem(&trie, longstr, longsize));
 
-	memset(longstr, 0xAA, longsize/2);
-	assert(!trie_find_mem(&trie, longstr, longsize));
-	assert(trie_insert_mem(&trie, longstr, longsize));
+	memset(longstr, 0xAA, longsize / 2);
+	ret &= bfs_check(!trie_find_mem(&trie, longstr, longsize));
+	ret &= bfs_check(trie_insert_mem(&trie, longstr, longsize));
 
 	free(longstr);
 	trie_destroy(&trie);
-	return EXIT_SUCCESS;
+	return ret;
 }
diff --git a/tests/util.sh b/tests/util.sh
new file mode 100644
index 0000000..3969db5
--- /dev/null
+++ b/tests/util.sh
@@ -0,0 +1,182 @@
+#!/hint/bash
+
+# Copyright © Tavian Barnes <tavianator@tavianator.com>
+# SPDX-License-Identifier: 0BSD
+
+## Utility functions
+
+# Portable realpath(1)
+_realpath() (
+    cd "$(dirname -- "$1")"
+    echo "$PWD/$(basename -- "$1")"
+)
+
+# Globals
+ROOT=$(_realpath "$(dirname -- "$TESTS")")
+TESTS="$ROOT/tests"
+BIN="$ROOT/bin"
+MKSOCK="$BIN/tests/mksock"
+XTOUCH="$BIN/tests/xtouch"
+UNAME=$(uname)
+
+# Standardize the environment
+stdenv() {
+    export LC_ALL=C
+    export TZ=UTC0
+
+    local SAN_OPTIONS="abort_on_error=1:halt_on_error=1:log_to_syslog=0"
+    export ASAN_OPTIONS="$SAN_OPTIONS"
+    export LSAN_OPTIONS="$SAN_OPTIONS"
+    export MSAN_OPTIONS="$SAN_OPTIONS"
+    export TSAN_OPTIONS="$SAN_OPTIONS"
+    export UBSAN_OPTIONS="$SAN_OPTIONS"
+
+    export LS_COLORS=""
+    unset BFS_COLORS
+
+    if [ "$UNAME" = Darwin ]; then
+        # ASan on macOS likes to report
+        #
+        #     malloc: nano zone abandoned due to inability to preallocate reserved vm space.
+        #
+        # to syslog, which as a side effect opens a socket which might take the
+        # place of one of the standard streams if the process is launched with
+        # it closed.  This environment variable avoids the message.
+        export MallocNanoZone=0
+    fi
+
+    # Count the inherited FDs
+    if [ -d /proc/self/fd ]; then
+        local fds=/proc/self/fd
+    else
+        local fds=/dev/fd
+    fi
+    # We use ls $fds on purpose, rather than e.g. ($fds/*), to avoid counting
+    # internal bash fds that are not exposed to spawned processes
+    NOPENFD=$(ls -1q "$fds/" 2>/dev/null | wc -l)
+    NOPENFD=$((NOPENFD > 3 ? NOPENFD - 1 : 3))
+
+    # Close stdin so bfs doesn't think we're interactive
+    # dup() the standard fds for logging even when redirected
+    exec </dev/null {DUPOUT}>&1 {DUPERR}>&2
+}
+
+# Drop root priviliges or bail
+drop_root() {
+    if command -v capsh &>/dev/null; then
+        if capsh --has-p=cap_dac_override &>/dev/null || capsh --has-p=cap_dac_read_search &>/dev/null; then
+	    if [ -n "${BFS_TRIED_DROP:-}" ]; then
+                color cat >&2 <<EOF
+${RED}error:${RST} Failed to drop capabilities.
+EOF
+
+	        exit 1
+	    fi
+
+            color cat >&2 <<EOF
+${YLW}warning:${RST} Running as ${BLD}$(id -un)${RST} is not recommended.  Dropping ${BLD}cap_dac_override${RST} and
+${BLD}cap_dac_read_search${RST}.
+
+EOF
+
+            BFS_TRIED_DROP=y exec capsh \
+                --drop=cap_dac_override,cap_dac_read_search \
+                --caps=cap_dac_override,cap_dac_read_search-eip \
+                -- "$0" "$@"
+        fi
+    elif ((EUID == 0)); then
+        UNLESS=
+        if [ "$UNAME" = "Linux" ]; then
+	    UNLESS=" unless ${GRN}capsh${RST} is installed"
+        fi
+
+        color cat >&2 <<EOF
+${RED}error:${RST} These tests expect filesystem permissions to be enforced, and therefore
+will not work when run as ${BLD}$(id -un)${RST}${UNLESS}.
+EOF
+        exit 1
+    fi
+}
+
+## Debugging
+
+# Get the bash call stack
+callers() {
+    local frame=0
+    while caller $frame; do
+        ((++frame))
+    done
+}
+
+# Print a message including path, line number, and command
+debug() {
+    local file="$1"
+    local line="$2"
+    local msg="$3"
+    local cmd="$(awk "NR == $line" "$file" 2>/dev/null)" || :
+    file="${file/#*\/tests\//tests/}"
+
+    color printf "${BLD}%s:%d:${RST} %s\n    %s\n" "$file" "$line" "$msg" "$cmd"
+}
+
+## Deferred cleanup
+
+# Quote a command safely for eval
+quote() {
+    printf '%q' "$1"
+    shift
+    if (($# > 0)); then
+        printf ' %q' "$@"
+    fi
+}
+
+DEFER_LEVEL=-1
+
+# Run a command when this (sub)shell exits
+defer() {
+    # Check if the EXIT trap is already set
+    if ((DEFER_LEVEL != BASH_SUBSHELL)); then
+        DEFER_LEVEL=$BASH_SUBSHELL
+        DEFER_CMDS=()
+        DEFER_LINES=()
+        DEFER_FILES=()
+        trap pop_defers EXIT
+    fi
+
+    DEFER_CMDS+=("$(quote "$@")")
+
+    local line file
+    read -r line file < <(caller)
+    DEFER_LINES+=("$line")
+    DEFER_FILES+=("$file")
+}
+
+# Pop a single command from the defer stack and run it
+pop_defer() {
+    local cmd="${DEFER_CMDS[-1]}"
+    local file="${DEFER_FILES[-1]}"
+    local line="${DEFER_LINES[-1]}"
+    unset "DEFER_CMDS[-1]"
+    unset "DEFER_FILES[-1]"
+    unset "DEFER_LINES[-1]"
+
+    local ret=0
+    eval "$cmd" || ret=$?
+
+    if ((ret != 0)); then
+        debug "$file" $line "${RED}error $ret${RST}" >&$DUPERR
+    fi
+
+    return $ret
+}
+
+# Run all deferred commands
+pop_defers() {
+    local ret=0
+
+    while ((${#DEFER_CMDS[@]} > 0)); do
+        pop_defer || ret=$?
+    done
+
+    return $ret
+}
diff --git a/tests/xspawn.c b/tests/xspawn.c
new file mode 100644
index 0000000..785ea48
--- /dev/null
+++ b/tests/xspawn.c
@@ -0,0 +1,197 @@
+// Copyright © Tavian Barnes <tavianator@tavianator.com>
+// SPDX-License-Identifier: 0BSD
+
+#include "prelude.h"
+#include "tests.h"
+#include "alloc.h"
+#include "bfstd.h"
+#include "dstring.h"
+#include "xspawn.h"
+#include <stdlib.h>
+#include <string.h>
+#include <sys/wait.h>
+
+/** Duplicate the current environment. */
+static char **envdup(void) {
+	extern char **environ;
+
+	char **envp = NULL;
+	size_t envc = 0;
+
+	for (char **var = environ; ; ++var) {
+		char *copy = NULL;
+		if (*var) {
+			copy = strdup(*var);
+			if (!copy) {
+				goto fail;
+			}
+		}
+
+		char **dest = RESERVE(char *, &envp, &envc);
+		if (!dest) {
+			free(copy);
+			goto fail;
+		}
+		*dest = copy;
+
+		if (!*var) {
+			break;
+		}
+	}
+
+	return envp;
+
+fail:
+	for (size_t i = 0; i < envc; ++i) {
+		free(envp[i]);
+	}
+	free(envp);
+	return NULL;
+}
+
+/** Check that we resolve executables in $PATH correctly. */
+static bool check_use_path(bool use_posix) {
+	bool ret = true;
+
+	struct bfs_spawn spawn;
+	ret &= bfs_pcheck(bfs_spawn_init(&spawn) == 0);
+	if (!ret) {
+		goto out;
+	}
+
+	spawn.flags |= BFS_SPAWN_USE_PATH;
+	if (!use_posix) {
+		spawn.flags &= ~BFS_SPAWN_USE_POSIX;
+	}
+
+	ret &= bfs_pcheck(bfs_spawn_addopen(&spawn, 10, "bin", O_RDONLY | O_DIRECTORY, 0) == 0);
+	ret &= bfs_pcheck(bfs_spawn_adddup2(&spawn, 10, 11) == 0);
+	ret &= bfs_pcheck(bfs_spawn_addclose(&spawn, 10) == 0);
+	ret &= bfs_pcheck(bfs_spawn_addfchdir(&spawn, 11) == 0);
+	ret &= bfs_pcheck(bfs_spawn_addclose(&spawn, 11) == 0);
+	if (!ret) {
+		goto destroy;
+	}
+
+	// Check that $PATH is resolved in the parent's environment
+	char **envp;
+	ret &= bfs_pcheck(envp = envdup());
+	if (!ret) {
+		goto destroy;
+	}
+
+	// Check that $PATH is resolved after the file actions
+	char *old_path = getenv("PATH");
+	dchar *new_path = NULL;
+	if (old_path) {
+		ret &= bfs_pcheck(old_path = strdup(old_path));
+		if (!ret) {
+			goto env;
+		}
+		new_path = dstrprintf("tests:%s", old_path);
+	} else {
+		new_path = dstrdup("tests");
+	}
+	ret &= bfs_check(new_path);
+	if (!ret) {
+		goto path;
+	}
+
+	ret &= bfs_pcheck(setenv("PATH", new_path, true) == 0);
+	if (!ret) {
+		goto path;
+	}
+
+	char *argv[] = {"xspawnee", old_path, NULL};
+	pid_t pid = bfs_spawn("xspawnee", &spawn, argv, envp);
+	ret &= bfs_pcheck(pid >= 0, "bfs_spawn()");
+	if (!ret) {
+		goto unset;
+	}
+
+	int wstatus;
+	ret &= bfs_pcheck(xwaitpid(pid, &wstatus, 0) == pid)
+		&& bfs_check(WIFEXITED(wstatus));
+	if (ret) {
+		int wexit = WEXITSTATUS(wstatus);
+		ret &= bfs_check(wexit == EXIT_SUCCESS, "xspawnee: exit(%d)", wexit);
+	}
+
+unset:
+	if (old_path) {
+		ret &= bfs_pcheck(setenv("PATH", old_path, true) == 0);
+	} else {
+		ret &= bfs_pcheck(unsetenv("PATH") == 0);
+	}
+path:
+	dstrfree(new_path);
+	free(old_path);
+env:
+	for (char **var = envp; *var; ++var) {
+		free(*var);
+	}
+	free(envp);
+destroy:
+	ret &= bfs_pcheck(bfs_spawn_destroy(&spawn) == 0);
+out:
+	return ret;
+}
+
+/** Check path resolution of non-existent executables. */
+static bool check_enoent(bool use_posix) {
+	bool ret = true;
+
+	struct bfs_spawn spawn;
+	ret &= bfs_pcheck(bfs_spawn_init(&spawn) == 0);
+	if (!ret) {
+		goto out;
+	}
+
+	spawn.flags |= BFS_SPAWN_USE_PATH;
+	if (!use_posix) {
+		spawn.flags &= ~BFS_SPAWN_USE_POSIX;
+	}
+
+	char *argv[] = {"eW6f5RM9Qi", NULL};
+	pid_t pid = bfs_spawn("eW6f5RM9Qi", &spawn, argv, NULL);
+	ret &= bfs_pcheck(pid < 0 && errno == ENOENT, "bfs_spawn()");
+
+	ret &= bfs_pcheck(bfs_spawn_destroy(&spawn) == 0);
+out:
+	return ret;
+}
+
+static bool check_resolve(void) {
+	bool ret = true;
+	char *exe;
+
+	exe = bfs_spawn_resolve("sh");
+	ret &= bfs_pcheck(exe, "bfs_spawn_resolve('sh')");
+	free(exe);
+
+	exe = bfs_spawn_resolve("/bin/sh");
+	ret &= bfs_pcheck(exe && strcmp(exe, "/bin/sh") == 0);
+	free(exe);
+
+	exe = bfs_spawn_resolve("bin/tests/xspawnee");
+	ret &= bfs_pcheck(exe && strcmp(exe, "bin/tests/xspawnee") == 0);
+	free(exe);
+
+	ret &= bfs_pcheck(!bfs_spawn_resolve("eW6f5RM9Qi") && errno == ENOENT);
+
+	return ret;
+}
+
+bool check_xspawn(void) {
+	bool ret = true;
+
+	ret &= check_use_path(true);
+	ret &= check_use_path(false);
+
+	ret &= check_enoent(true);
+	ret &= check_enoent(false);
+
+	ret &= check_resolve();
+
+	return ret;
+}
diff --git a/tests/xspawnee.c b/tests/xspawnee.c
new file mode 100644
index 0000000..b0a76ca
--- /dev/null
+++ b/tests/xspawnee.c
@@ -0,0 +1,17 @@
+// Copyright © Tavian Barnes <tavianator@tavianator.com>
+// SPDX-License-Identifier: 0BSD
+
+#include <stdlib.h>
+#include <string.h>
+
+/** Child binary for bfs_spawn() tests. */
+int main(int argc, char *argv[]) {
+	if (argc >= 2) {
+		const char *path = getenv("PATH");
+		if (!path || strcmp(path, argv[1]) != 0) {
+			return EXIT_FAILURE;
+		}
+	}
+
+	return EXIT_SUCCESS;
+}
diff --git a/tests/xtime.c b/tests/xtime.c
new file mode 100644
index 0000000..d9d6c5c
--- /dev/null
+++ b/tests/xtime.c
@@ -0,0 +1,195 @@
+// Copyright © Tavian Barnes <tavianator@tavianator.com>
+// SPDX-License-Identifier: 0BSD
+
+#include "prelude.h"
+#include "tests.h"
+#include "xtime.h"
+#include "bfstd.h"
+#include "diag.h"
+#include <errno.h>
+#include <limits.h>
+#include <stdint.h>
+#include <time.h>
+
+static bool tm_equal(const struct tm *tma, const struct tm *tmb) {
+	return tma->tm_year == tmb->tm_year
+		&& tma->tm_mon == tmb->tm_mon
+		&& tma->tm_mday == tmb->tm_mday
+		&& tma->tm_hour == tmb->tm_hour
+		&& tma->tm_min == tmb->tm_min
+		&& tma->tm_sec == tmb->tm_sec
+		&& tma->tm_wday == tmb->tm_wday
+		&& tma->tm_yday == tmb->tm_yday
+		&& tma->tm_isdst == tmb->tm_isdst;
+}
+
+/** Check one xgetdate() result. */
+static bool check_one_xgetdate(const char *str, int error, time_t expected) {
+	struct timespec ts;
+	int ret = xgetdate(str, &ts);
+
+	if (error) {
+		return bfs_pcheck(ret == -1 && errno == error, "xgetdate('%s')", str);
+	} else {
+		return bfs_pcheck(ret == 0, "xgetdate('%s')", str)
+			&& bfs_check(ts.tv_sec == expected && ts.tv_nsec == 0,
+				"xgetdate('%s'): %jd.%09jd != %jd",
+				str, (intmax_t)ts.tv_sec, (intmax_t)ts.tv_nsec, (intmax_t)expected);
+	}
+}
+
+/** xgetdate() tests. */
+static bool check_xgetdate(void) {
+	bool ret = true;
+
+	ret &= check_one_xgetdate("", EINVAL, 0);
+	ret &= check_one_xgetdate("????", EINVAL, 0);
+	ret &= check_one_xgetdate("1991", EINVAL, 0);
+	ret &= check_one_xgetdate("1991-??", EINVAL, 0);
+	ret &= check_one_xgetdate("1991-12", EINVAL, 0);
+	ret &= check_one_xgetdate("1991-12-", EINVAL, 0);
+	ret &= check_one_xgetdate("1991-12-??", EINVAL, 0);
+	ret &= check_one_xgetdate("1991-12-14", 0, 692668800);
+	ret &= check_one_xgetdate("1991-12-14-", EINVAL, 0);
+	ret &= check_one_xgetdate("1991-12-14T", EINVAL, 0);
+	ret &= check_one_xgetdate("1991-12-14T??", EINVAL, 0);
+	ret &= check_one_xgetdate("1991-12-14T10", 0, 692704800);
+	ret &= check_one_xgetdate("1991-12-14T10:??", EINVAL, 0);
+	ret &= check_one_xgetdate("1991-12-14T10:11", 0, 692705460);
+	ret &= check_one_xgetdate("1991-12-14T10:11:??", EINVAL, 0);
+	ret &= check_one_xgetdate("1991-12-14T10:11:12", 0, 692705472);
+	ret &= check_one_xgetdate("1991-12-14T10Z", 0, 692704800);
+	ret &= check_one_xgetdate("1991-12-14T10:11Z", 0, 692705460);
+	ret &= check_one_xgetdate("1991-12-14T10:11:12Z", 0, 692705472);
+	ret &= check_one_xgetdate("1991-12-14T10:11:12?", EINVAL, 0);
+	ret &= check_one_xgetdate("1991-12-14T03-07", 0, 692704800);
+	ret &= check_one_xgetdate("1991-12-14T06:41-03:30", 0, 692705460);
+	ret &= check_one_xgetdate("1991-12-14T03:11:12-07:00", 0, 692705472);
+	ret &= check_one_xgetdate("19911214 031112-0700", 0, 692705472);;
+
+	return ret;
+}
+
+#define TM_FORMAT "%04d-%02d-%02d %02d:%02d:%02d (%d/7, %d/365%s)"
+
+#define TM_PRINTF(tm) \
+	(1900 + (tm).tm_year), (tm).tm_mon, (tm).tm_mday, \
+	(tm).tm_hour, (tm).tm_min, (tm).tm_sec, \
+	((tm).tm_wday + 1), ((tm).tm_yday + 1), \
+	((tm).tm_isdst ? ((tm).tm_isdst < 0 ? ", DST?" : ", DST") : "")
+
+/** Check one xmktime() result. */
+static bool check_one_xmktime(time_t expected) {
+	struct tm tm;
+	if (!localtime_r(&expected, &tm)) {
+		bfs_diag("localtime_r(%jd): %s", (intmax_t)expected, xstrerror(errno));
+		return false;
+	}
+
+	time_t actual;
+	return bfs_pcheck(xmktime(&tm, &actual) == 0, "xmktime(" TM_FORMAT ")", TM_PRINTF(tm))
+		&& bfs_check(actual == expected, "xmktime(" TM_FORMAT "): %jd != %jd", TM_PRINTF(tm), (intmax_t)actual, (intmax_t)expected);
+}
+
+/** xmktime() tests. */
+static bool check_xmktime(void) {
+	bool ret = true;
+
+	for (time_t time = -10; time <= 10; ++time) {
+		ret &= check_one_xmktime(time);
+	}
+
+	// Attempt to trigger overflow (but don't test for it, since it's not mandatory)
+	struct tm tm = {
+		.tm_year = INT_MAX,
+		.tm_mon = INT_MAX,
+		.tm_mday = INT_MAX,
+		.tm_hour = INT_MAX,
+		.tm_min = INT_MAX,
+		.tm_sec = INT_MAX,
+		.tm_isdst = -1,
+	};
+	time_t time;
+	xmktime(&tm, &time);
+
+	return ret;
+}
+
+/** Check one xtimegm() result. */
+static bool check_one_xtimegm(const struct tm *tm) {
+	struct tm tma = *tm, tmb = *tm;
+	time_t ta, tb;
+	ta = mktime(&tma);
+	if (xtimegm(&tmb, &tb) != 0) {
+		tb = -1;
+	}
+
+	bool ret = true;
+	ret &= bfs_check(ta == tb, "%jd != %jd", (intmax_t)ta, (intmax_t)tb);
+	ret &= bfs_check(ta == -1 || tm_equal(&tma, &tmb));
+
+	if (!ret) {
+		bfs_diag("mktime():  " TM_FORMAT, TM_PRINTF(tma));
+		bfs_diag("xtimegm(): " TM_FORMAT, TM_PRINTF(tmb));
+		bfs_diag("(input):   " TM_FORMAT, TM_PRINTF(*tm));
+	}
+
+	return ret;
+}
+
+#if !BFS_HAS_TIMEGM
+/** Check an overflowing xtimegm() call. */
+static bool check_xtimegm_overflow(const struct tm *tm) {
+	struct tm copy = *tm;
+	time_t time = 123;
+
+	bool ret = true;
+	ret &= bfs_check(xtimegm(&copy, &time) == -1 && errno == EOVERFLOW);
+	ret &= bfs_check(tm_equal(&copy, tm));
+	ret &= bfs_check(time == 123);
+
+	if (!ret) {
+		bfs_diag("xtimegm(): " TM_FORMAT, TM_PRINTF(copy));
+		bfs_diag("(input):   " TM_FORMAT, TM_PRINTF(*tm));
+	}
+
+	return ret;
+}
+#endif
+
+/** xtimegm() tests. */
+static bool check_xtimegm(void) {
+	bool ret = true;
+
+	struct tm tm = {
+		.tm_isdst = -1,
+	};
+
+	// Check equivalence with mktime()
+	for (tm.tm_year =  10; tm.tm_year <= 200; tm.tm_year += 10)
+	for (tm.tm_mon  =  -3; tm.tm_mon  <=  15; tm.tm_mon  +=  3)
+	for (tm.tm_mday = -31; tm.tm_mday <=  61; tm.tm_mday +=  4)
+	for (tm.tm_hour =  -1; tm.tm_hour <=  24; tm.tm_hour +=  5)
+	for (tm.tm_min  =  -1; tm.tm_min  <=  60; tm.tm_min  += 31)
+	for (tm.tm_sec  = -60; tm.tm_sec  <= 120; tm.tm_sec  +=  5) {
+		ret &= check_one_xtimegm(&tm);
+	}
+
+#if !BFS_HAS_TIMEGM
+	// Check integer overflow cases
+	ret &= check_xtimegm_overflow(&(struct tm) { .tm_sec = INT_MAX, .tm_min = INT_MAX });
+	ret &= check_xtimegm_overflow(&(struct tm) { .tm_min = INT_MAX, .tm_hour = INT_MAX });
+	ret &= check_xtimegm_overflow(&(struct tm) { .tm_hour = INT_MAX, .tm_mday = INT_MAX });
+	ret &= check_xtimegm_overflow(&(struct tm) { .tm_mon = INT_MAX, .tm_year = INT_MAX });
+#endif
+
+	return ret;
+}
+
+bool check_xtime(void) {
+	bool ret = true;
+	ret &= check_xgetdate();
+	ret &= check_xmktime();
+	ret &= check_xtimegm();
+	return ret;
+}
diff --git a/tests/xtimegm.c b/tests/xtimegm.c
deleted file mode 100644
index d774b9e..0000000
--- a/tests/xtimegm.c
+++ /dev/null
@@ -1,107 +0,0 @@
-/****************************************************************************
- * bfs                                                                      *
- * Copyright (C) 2020 Tavian Barnes <tavianator@tavianator.com>             *
- *                                                                          *
- * Permission to use, copy, modify, and/or distribute this software for any *
- * purpose with or without fee is hereby granted.                           *
- *                                                                          *
- * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES *
- * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF         *
- * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR  *
- * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES   *
- * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN    *
- * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF  *
- * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.           *
- ****************************************************************************/
-
-#include "../src/xtime.h"
-#include <stdbool.h>
-#include <stdint.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <time.h>
-
-static bool tm_equal(const struct tm *tma, const struct tm *tmb) {
-	if (tma->tm_year != tmb->tm_year) {
-		return false;
-	}
-	if (tma->tm_mon != tmb->tm_mon) {
-		return false;
-	}
-	if (tma->tm_mday != tmb->tm_mday) {
-		return false;
-	}
-	if (tma->tm_hour != tmb->tm_hour) {
-		return false;
-	}
-	if (tma->tm_min != tmb->tm_min) {
-		return false;
-	}
-	if (tma->tm_sec != tmb->tm_sec) {
-		return false;
-	}
-	if (tma->tm_wday != tmb->tm_wday) {
-		return false;
-	}
-	if (tma->tm_yday != tmb->tm_yday) {
-		return false;
-	}
-	if (tma->tm_isdst != tmb->tm_isdst) {
-		return false;
-	}
-
-	return true;
-}
-
-static void tm_print(FILE *file, const struct tm *tm) {
-	fprintf(file, "Y%d M%d D%d  h%d m%d s%d  wd%d yd%d%s\n",
-	        tm->tm_year, tm->tm_mon, tm->tm_mday,
-	        tm->tm_hour, tm->tm_min, tm->tm_sec,
-	        tm->tm_wday, tm->tm_yday,
-		tm->tm_isdst ? (tm->tm_isdst < 0 ? " (DST?)" : " (DST)") : "");
-}
-
-int main(void) {
-	if (setenv("TZ", "UTC0", true) != 0) {
-		perror("setenv()");
-		return EXIT_FAILURE;
-	}
-
-	struct tm tm = {
-		.tm_isdst = -1,
-	};
-
-	for (tm.tm_year = 10; tm.tm_year <= 200; tm.tm_year += 10)
-	for (tm.tm_mon = -3; tm.tm_mon <= 15; tm.tm_mon += 3)
-	for (tm.tm_mday = -31; tm.tm_mday <= 61; tm.tm_mday += 4)
-	for (tm.tm_hour = -1; tm.tm_hour <= 24; tm.tm_hour += 5)
-	for (tm.tm_min = -1; tm.tm_min <= 60; tm.tm_min += 31)
-	for (tm.tm_sec = -60; tm.tm_sec <= 120; tm.tm_sec += 5) {
-		struct tm tma = tm, tmb = tm;
-		time_t ta, tb;
-		ta = mktime(&tma);
-		if (xtimegm(&tmb, &tb) != 0) {
-			tb = -1;
-		}
-
-		bool fail = false;
-		if (ta != tb) {
-			printf("Mismatch:  %jd != %jd\n", (intmax_t)ta, (intmax_t)tb);
-			fail = true;
-		}
-		if (ta != -1 && !tm_equal(&tma, &tmb)) {
-			printf("mktime():  ");
-			tm_print(stdout, &tma);
-			printf("xtimegm(): ");
-			tm_print(stdout, &tmb);
-			fail = true;
-		}
-		if (fail) {
-			printf("Input:     ");
-			tm_print(stdout, &tm);
-			return EXIT_FAILURE;
-		}
-	}
-
-	return EXIT_SUCCESS;
-}
diff --git a/tests/xtouch.c b/tests/xtouch.c
index 9a91ec7..cd41842 100644
--- a/tests/xtouch.c
+++ b/tests/xtouch.c
@@ -1,28 +1,17 @@
-/****************************************************************************
- * bfs                                                                      *
- * Copyright (C) 2022 Tavian Barnes <tavianator@tavianator.com>             *
- *                                                                          *
- * Permission to use, copy, modify, and/or distribute this software for any *
- * purpose with or without fee is hereby granted.                           *
- *                                                                          *
- * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES *
- * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF         *
- * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR  *
- * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES   *
- * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN    *
- * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF  *
- * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.           *
- ****************************************************************************/
-
-#include "../src/bfstd.h"
-#include "../src/xtime.h"
+// Copyright © Tavian Barnes <tavianator@tavianator.com>
+// SPDX-License-Identifier: 0BSD
+
+#include "prelude.h"
+#include "bfstd.h"
+#include "sanity.h"
+#include "xtime.h"
 #include <errno.h>
 #include <fcntl.h>
-#include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/stat.h>
+#include <sys/types.h>
 #include <time.h>
 #include <unistd.h>
 
@@ -49,85 +38,128 @@ struct args {
 	mode_t pmode;
 };
 
-/** Compute flags for fstatat()/utimensat(). */
-static int at_flags(const struct args *args) {
-	if (args->flags & NO_FOLLOW) {
-		return AT_SYMLINK_NOFOLLOW;
-	} else {
-		return 0;
+/** Open (and maybe create) a single directory. */
+static int open_dir(const struct args *args, int dfd, const char *path) {
+	int ret = openat(dfd, path, O_SEARCH | O_DIRECTORY);
+
+	if (ret < 0 && errno == ENOENT && (args->flags & CREATE_PARENTS)) {
+		if (mkdirat(dfd, path, args->pmode) == 0 || errno == EEXIST) {
+			ret = openat(dfd, path, O_SEARCH | O_DIRECTORY);
+		}
 	}
+
+	return ret;
 }
 
-/** Create any parent directories of the given path. */
-static int mkdirs(const char *path, mode_t mode) {
-	char *copy = strdup(path);
-	if (!copy) {
+/** Open (and maybe create) the parent directory of the path. */
+static int open_parent(const struct args *args, const char **path) {
+	size_t max = xbaseoff(*path);
+	if (max == 0) {
+		return AT_FDCWD;
+	}
+
+	char *dir = strndup(*path, max);
+	if (!dir) {
 		return -1;
 	}
 
-	int ret = -1;
-	char *cur = copy + strspn(copy, "/");
-	while (true) {
-		cur += strcspn(cur, "/");
+	// Optimistically try the whole path first
+	int dfd = open_dir(args, AT_FDCWD, dir);
+	if (dfd >= 0) {
+		goto done;
+	}
 
-		char *next = cur + strspn(cur, "/");
-		if (!*next) {
-			ret = 0;
-			break;
+	if (errno == ENOENT) {
+		if (!(args->flags & CREATE_PARENTS)) {
+			goto err;
 		}
+	} else if (!errno_is_like(ENAMETOOLONG)) {
+		goto err;
+	}
 
-		*cur = '\0';
-		if (mkdir(copy, mode) != 0 && errno != EEXIST) {
-			break;
+	// Open the parents one-at-a-time
+	dfd = AT_FDCWD;
+	char *cur = dir;
+	while (*cur) {
+		char *next = cur;
+		next += strcspn(next, "/");
+		next += strspn(next, "/");
+
+		char c = *next;
+		*next = '\0';
+
+		int parent = dfd;
+		dfd = open_dir(args, parent, cur);
+		if (parent >= 0) {
+			close_quietly(parent);
 		}
-		*cur = '/';
+		if (dfd < 0) {
+			goto err;
+		}
+
+		*next = c;
 		cur = next;
 	}
 
-	free(copy);
-	return ret;
+done:
+	*path += max;
+err:
+	free(dir);
+	return dfd;
+}
+
+/** Compute flags for fstatat()/utimensat(). */
+static int at_flags(const struct args *args) {
+	if (args->flags & NO_FOLLOW) {
+		return AT_SYMLINK_NOFOLLOW;
+	} else {
+		return 0;
+	}
 }
 
 /** Touch one path. */
 static int xtouch(const struct args *args, const char *path) {
-	int ret = utimensat(AT_FDCWD, path, args->times, at_flags(args));
+	int dfd = open_parent(args, &path);
+	if (dfd < 0 && dfd != AT_FDCWD) {
+		return -1;
+	}
+
+	int ret = utimensat(dfd, path, args->times, at_flags(args));
 	if (ret == 0 || errno != ENOENT) {
-		return ret;
+		goto done;
 	}
 
 	if (args->flags & NO_CREATE) {
-		return 0;
-	} else if (args->flags & CREATE_PARENTS) {
-		if (mkdirs(path, args->pmode) != 0) {
-			return -1;
-		}
+		ret = 0;
+		goto done;
 	}
 
 	size_t len = strlen(path);
 	if (len > 0 && path[len - 1] == '/') {
-		if (mkdir(path, args->dmode) != 0) {
-			return -1;
+		if (mkdirat(dfd, path, args->dmode) == 0) {
+			ret = utimensat(dfd, path, args->times, at_flags(args));
 		}
-
-		return utimensat(AT_FDCWD, path, args->times, at_flags(args));
 	} else {
-		int fd = open(path, O_WRONLY | O_CREAT, args->fmode);
-		if (fd < 0) {
-			return -1;
-		}
-
-		if (futimens(fd, args->times) != 0) {
-			int error = errno;
-			close(fd);
-			errno = error;
-			return -1;
+		int fd = openat(dfd, path, O_WRONLY | O_CREAT, args->fmode);
+		if (fd >= 0) {
+			if (futimens(fd, args->times) == 0) {
+				ret = xclose(fd);
+			} else {
+				close_quietly(fd);
+			}
 		}
+	}
 
-		return close(fd);
+done:
+	if (dfd >= 0) {
+		close_quietly(dfd);
 	}
+	return ret;
 }
 
 int main(int argc, char *argv[]) {
+	tzset();
+
 	mode_t mask = umask(0);
 
 	struct args args = {
@@ -187,6 +219,8 @@ int main(int argc, char *argv[]) {
 	if (marg) {
 		char *end;
 		long mode = strtol(marg, &end, 8);
+		// https://github.com/llvm/llvm-project/issues/64946
+		sanitize_init(&end);
 		if (*marg && !*end && mode >= 0 && mode < 01000) {
 			args.fmode = args.dmode = mode;
 		} else {
@@ -200,14 +234,14 @@ int main(int argc, char *argv[]) {
 	if (rarg) {
 		struct stat buf;
 		if (fstatat(AT_FDCWD, rarg, &buf, at_flags(&args)) != 0) {
-			fprintf(stderr, "%s: '%s': %s\n", cmd, rarg, strerror(errno));
+			fprintf(stderr, "%s: '%s': %s\n", cmd, rarg, xstrerror(errno));
 			return EXIT_FAILURE;
 		}
-		times[0] = buf.st_atim;
-		times[1] = buf.st_mtim;
+		times[0] = ST_ATIM(buf);
+		times[1] = ST_MTIM(buf);
 	} else if (darg) {
 		if (xgetdate(darg, &times[0]) != 0) {
-			fprintf(stderr, "%s: Parsing time '%s' failed: %s\n", cmd, darg, strerror(errno));
+			fprintf(stderr, "%s: Parsing time '%s' failed: %s\n", cmd, darg, xstrerror(errno));
 			return EXIT_FAILURE;
 		}
 		times[1] = times[0];
@@ -240,7 +274,7 @@ int main(int argc, char *argv[]) {
 	for (; optind < argc; ++optind) {
 		const char *path = argv[optind];
 		if (xtouch(&args, path) != 0) {
-			fprintf(stderr, "%s: '%s': %s\n", cmd, path, strerror(errno));
+			fprintf(stderr, "%s: '%s': %s\n", cmd, path, xstrerror(errno));
 			ret = EXIT_FAILURE;
 		}
 	}