Remove TMPDIR dependency from tests/

Tests are now executed in a test-specific temporary directory, so test
output on failure should be reproducible/reusable as-is without needing
to have TMPDIR defined (as it only exists by default under macOS).

tests/checks/basic.fish

@@ -42,12 +42,12 @@ end
 # Simple function tests
 
 function foo
-    echo >$TMPDIR/fish_foo.txt $argv
+    echo >./fish_foo.txt $argv
 end
 
 foo hello
 
-cat $TMPDIR/fish_foo.txt |read foo
+cat ./fish_foo.txt |read foo
 
 if test $foo = hello;
   echo Test 2 pass
@@ -327,10 +327,10 @@ type -q -f fish_test_type_zzz ; echo $status
 
 # ensure that builtins that produce no output can still truncate files
 # (bug PCA almost reintroduced!)
-echo abc > $TMPDIR/file_truncation_test.txt
-cat $TMPDIR/file_truncation_test.txt
-echo -n > $TMPDIR/file_truncation_test.txt
-cat $TMPDIR/file_truncation_test.txt
+echo abc > ./file_truncation_test.txt
+cat ./file_truncation_test.txt
+echo -n > ./file_truncation_test.txt
+cat ./file_truncation_test.txt
 #CHECK: abc
 
 # Test events.

tests/checks/redirect.fish

@@ -60,15 +60,16 @@ foo $tmpdir/bar
 cat $tmpdir/bar
 # CHECK: foo
 
-rm -Rf $tmpdir
-
 # Verify that we can turn stderr into stdout and then pipe it
 # Note that the order here has historically been unspecified - 'errput' could conceivably appear before 'output'.
 begin
     echo output
     echo errput 1>&2
-end 2>&1 | sort | tee $TMPDIR/tee_test.txt
-cat $TMPDIR/tee_test.txt
+end 2>&1 | sort | tee $tmpdir/tee_test.txt
+cat $tmpdir/tee_test.txt
+
+rm -Rf $tmpdir
+
 #CHECK: errput
 #CHECK: output
 #CHECK: errput

tests/checks/tmux-complete.fish

@@ -6,9 +6,9 @@ set fish (builtin realpath $fish)
 
 # Isolated tmux. tmux can't handle session sockets in paths that are too long, and macOS has a very
 # long $TMPDIR, so use a relative path - except macOS doesn't have `realpath --relative-to`...
-# We have a unique TMPDIR assigned by the test driver, so this will work so long as `tmux` is only
-# invoked from the same PWD.
-set tmpdir (command mktemp -d $TMPDIR/tmp.XXXXXXXX)
+# We are cd'd into a unique temp dir created/assigned by the test driver, so this will work so long
+# as `tmux` is only invoked from the same PWD.
+set tmpdir (command mktemp -d ./tmp.XXXXXXXX)
 cd $tmpdir
 set -g tmux tmux -S ./.tmux-socket -f /dev/null
 

tests/checks/wildcard.fish

@@ -18,13 +18,13 @@ rm -Rf $dir
 
 # Verify that we can do wildcard expansion when we don't have read access to some path components.
 # See #2099
-set -l where $TMPDIR/fish_wildcard_permissions_test/noaccess/yesaccess
+set -l where ./fish_wildcard_permissions_test/noaccess/yesaccess
 mkdir -p $where
 chmod 300 (dirname $where) # no read permissions
 mkdir -p $where
 # "__env.fish" here to confirm ordering - #6593.
 touch $where/alpha.txt $where/beta.txt $where/delta.txt $where/__env.fish
-echo $where/* | string replace -a $TMPDIR '$TMPDIR'
-#CHECK: $TMPDIR/fish_wildcard_permissions_test/noaccess/yesaccess/__env.fish $TMPDIR/fish_wildcard_permissions_test/noaccess/yesaccess/alpha.txt $TMPDIR/fish_wildcard_permissions_test/noaccess/yesaccess/beta.txt $TMPDIR/fish_wildcard_permissions_test/noaccess/yesaccess/delta.txt
+echo $where/*
+#CHECK: ./fish_wildcard_permissions_test/noaccess/yesaccess/__env.fish ./fish_wildcard_permissions_test/noaccess/yesaccess/alpha.txt ./fish_wildcard_permissions_test/noaccess/yesaccess/beta.txt ./fish_wildcard_permissions_test/noaccess/yesaccess/delta.txt
 chmod 700 (dirname $where) # so we can delete it
-rm -rf $TMPDIR/fish_wildcard_permissions_test
+rm -rf ./fish_wildcard_permissions_test

tests/test_driver.sh

@@ -112,10 +112,12 @@ export suppress_color
 # Source test util functions at startup
 fish_init_cmd="${fish_init_cmd} && source ${TESTS_ROOT}/test_util.fish";
 
-# Run the test script, but don't exec so we can do cleanup after it succeeds/fails
-env HOME="$homedir" "${BUILD_ROOT}/test/root/bin/fish" \
+# Run the test script, but don't exec so we can do cleanup after it succeeds/fails. Each test is
+# launched directly within its TMPDIR, so that the fish tests themselves do not need to refer to
+# TMPDIR (to ensure their output as displayed in case of failure by littlecheck is reproducible).
+(cd $TMPDIR; env HOME="$homedir" "${BUILD_ROOT}/test/root/bin/fish" \
     --init-command "${fish_init_cmd}" \
-    "$fish_script" "$script_args"
+    "$fish_script" "$script_args")
 test_status="$?"
 
 rm -rf "$homedir"