tests: change "mkdir -p && write_script" to use "test_hook"

Change tests that used a "mkdir -p .git/hooks && write_script" pattern
to use the new "test_hook" helper instead. The new helper does not
create the .git/hooks directory, rather we assume that the default
template will do so for us.

An upcoming series[1] will extend "test_hook" to operate in a
"--template=" mode, but for now assuming that we have a .git/hooks
already is a safe assumption. If that assumption becomes false in the
future we'll only need to change 'test_hook", instead of all of these
callsites.

1. https://lore.kernel.org/git/cover-00.13-00000000000-20211212T201308Z-avarab@gmail.com/

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t0029-core-unsetenvvars.sh

@@ -12,8 +12,7 @@ then
 fi
 
 test_expect_success 'setup' '
-	mkdir -p "$TRASH_DIRECTORY/.git/hooks" &&
-	write_script "$TRASH_DIRECTORY/.git/hooks/pre-commit" <<-\EOF
+	test_hook --setup pre-commit <<-\EOF
 	echo $HOBBES >&2
 	EOF
 '

t/t1350-config-hooks-path.sh

@@ -6,11 +6,11 @@ test_description='Test the core.hooksPath configuration variable'
 
 test_expect_success 'set up a pre-commit hook in core.hooksPath' '
 	>actual &&
-	mkdir -p .git/custom-hooks .git/hooks &&
+	mkdir -p .git/custom-hooks &&
 	write_script .git/custom-hooks/pre-commit <<-\EOF &&
 	echo CUSTOM >>actual
 	EOF
-	write_script .git/hooks/pre-commit <<-\EOF
+	test_hook --setup pre-commit <<-\EOF
 	echo NORMAL >>actual
 	EOF
 '

t/t3404-rebase-interactive.sh

@@ -619,9 +619,7 @@ test_expect_success 'rebase a detached HEAD' '
 '
 
 test_expect_success 'rebase a commit violating pre-commit' '
-
-	mkdir -p .git/hooks &&
-	write_script .git/hooks/pre-commit <<-\EOF &&
+	test_hook pre-commit <<-\EOF &&
 	test -z "$(git diff --cached --check)"
 	EOF
 	echo "monde! " >> file1 &&
@@ -636,8 +634,6 @@ test_expect_success 'rebase a commit violating pre-commit' '
 '
 
 test_expect_success 'rebase with a file named HEAD in worktree' '
-
-	rm -fr .git/hooks &&
 	git reset --hard &&
 	git checkout -b branch3 A &&
 
@@ -1688,10 +1684,8 @@ test_expect_success 'valid author header when author contains single quote' '
 '
 
 test_expect_success 'post-commit hook is called' '
-	test_when_finished "rm -f .git/hooks/post-commit" &&
 	>actual &&
-	mkdir -p .git/hooks &&
-	write_script .git/hooks/post-commit <<-\EOS &&
+	test_hook post-commit <<-\EOS &&
 	git rev-parse HEAD >>actual
 	EOS
 	(

t/t3430-rebase-merges.sh

@@ -292,9 +292,9 @@ test_expect_success 'post-rewrite hook and fixups work for merges' '
 	git commit --fixup HEAD same2.t &&
 	fixup="$(git rev-parse HEAD)" &&
 
-	mkdir -p .git/hooks &&
-	test_when_finished "rm .git/hooks/post-rewrite" &&
-	echo "cat >actual" | write_script .git/hooks/post-rewrite &&
+	test_hook post-rewrite <<-\EOF &&
+	cat >actual
+	EOF
 
 	test_tick &&
 	git rebase -i --autosquash -r HEAD^^^ &&

t/t4150-am.sh

@@ -315,12 +315,10 @@ test_expect_success 'am --patch-format=hg applies hg patch' '
 '
 
 test_expect_success 'am with applypatch-msg hook' '
-	test_when_finished "rm -f .git/hooks/applypatch-msg" &&
 	rm -fr .git/rebase-apply &&
 	git reset --hard &&
 	git checkout first &&
-	mkdir -p .git/hooks &&
-	write_script .git/hooks/applypatch-msg <<-\EOF &&
+	test_hook applypatch-msg <<-\EOF &&
 	cat "$1" >actual-msg &&
 	echo hook-message >"$1"
 	EOF
@@ -335,12 +333,10 @@ test_expect_success 'am with applypatch-msg hook' '
 '
 
 test_expect_success 'am with failing applypatch-msg hook' '
-	test_when_finished "rm -f .git/hooks/applypatch-msg" &&
 	rm -fr .git/rebase-apply &&
 	git reset --hard &&
 	git checkout first &&
-	mkdir -p .git/hooks &&
-	write_script .git/hooks/applypatch-msg <<-\EOF &&
+	test_hook applypatch-msg <<-\EOF &&
 	exit 1
 	EOF
 	test_must_fail git am patch1 &&
@@ -350,12 +346,10 @@ test_expect_success 'am with failing applypatch-msg hook' '
 '
 
 test_expect_success 'am with pre-applypatch hook' '
-	test_when_finished "rm -f .git/hooks/pre-applypatch" &&
 	rm -fr .git/rebase-apply &&
 	git reset --hard &&
 	git checkout first &&
-	mkdir -p .git/hooks &&
-	write_script .git/hooks/pre-applypatch <<-\EOF &&
+	test_hook pre-applypatch <<-\EOF &&
 	git diff first >diff.actual
 	exit 0
 	EOF
@@ -368,12 +362,10 @@ test_expect_success 'am with pre-applypatch hook' '
 '
 
 test_expect_success 'am with failing pre-applypatch hook' '
-	test_when_finished "rm -f .git/hooks/pre-applypatch" &&
 	rm -fr .git/rebase-apply &&
 	git reset --hard &&
 	git checkout first &&
-	mkdir -p .git/hooks &&
-	write_script .git/hooks/pre-applypatch <<-\EOF &&
+	test_hook pre-applypatch <<-\EOF &&
 	exit 1
 	EOF
 	test_must_fail git am patch1 &&
@@ -383,12 +375,10 @@ test_expect_success 'am with failing pre-applypatch hook' '
 '
 
 test_expect_success 'am with post-applypatch hook' '
-	test_when_finished "rm -f .git/hooks/post-applypatch" &&
 	rm -fr .git/rebase-apply &&
 	git reset --hard &&
 	git checkout first &&
-	mkdir -p .git/hooks &&
-	write_script .git/hooks/post-applypatch <<-\EOF &&
+	test_hook post-applypatch <<-\EOF &&
 	git rev-parse HEAD >head.actual
 	git diff second >diff.actual
 	exit 0
@@ -403,12 +393,10 @@ test_expect_success 'am with post-applypatch hook' '
 '
 
 test_expect_success 'am with failing post-applypatch hook' '
-	test_when_finished "rm -f .git/hooks/post-applypatch" &&
 	rm -fr .git/rebase-apply &&
 	git reset --hard &&
 	git checkout first &&
-	mkdir -p .git/hooks &&
-	write_script .git/hooks/post-applypatch <<-\EOF &&
+	test_hook post-applypatch <<-\EOF &&
 	git rev-parse HEAD >head.actual
 	exit 1
 	EOF

t/t5403-post-checkout-hook.sh

@@ -10,8 +10,7 @@ export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 . ./test-lib.sh
 
 test_expect_success setup '
-	mkdir -p .git/hooks &&
-	write_script .git/hooks/post-checkout <<-\EOF &&
+	test_hook --setup post-checkout <<-\EOF &&
 	echo "$@" >.git/post-checkout.args
 	EOF
 	test_commit one &&

t/t5534-push-signed.sh

@@ -35,8 +35,7 @@ test_expect_success setup '
 
 test_expect_success 'unsigned push does not send push certificate' '
 	prepare_dst &&
-	mkdir -p dst/.git/hooks &&
-	write_script dst/.git/hooks/post-receive <<-\EOF &&
+	test_hook -C dst post-receive <<-\EOF &&
 	# discard the update list
 	cat >/dev/null
 	# record the push certificate
@@ -52,8 +51,7 @@ test_expect_success 'unsigned push does not send push certificate' '
 
 test_expect_success 'talking with a receiver without push certificate support' '
 	prepare_dst &&
-	mkdir -p dst/.git/hooks &&
-	write_script dst/.git/hooks/post-receive <<-\EOF &&
+	test_hook -C dst post-receive <<-\EOF &&
 	# discard the update list
 	cat >/dev/null
 	# record the push certificate
@@ -69,22 +67,19 @@ test_expect_success 'talking with a receiver without push certificate support' '
 
 test_expect_success 'push --signed fails with a receiver without push certificate support' '
 	prepare_dst &&
-	mkdir -p dst/.git/hooks &&
 	test_must_fail git push --signed dst noop ff +noff 2>err &&
 	test_i18ngrep "the receiving end does not support" err
 '
 
 test_expect_success 'push --signed=1 is accepted' '
 	prepare_dst &&
-	mkdir -p dst/.git/hooks &&
 	test_must_fail git push --signed=1 dst noop ff +noff 2>err &&
 	test_i18ngrep "the receiving end does not support" err
 '
 
 test_expect_success GPG 'no certificate for a signed push with no update' '
 	prepare_dst &&
-	mkdir -p dst/.git/hooks &&
-	write_script dst/.git/hooks/post-receive <<-\EOF &&
+	test_hook -C dst post-receive <<-\EOF &&
 	if test -n "${GIT_PUSH_CERT-}"
 	then
 		git cat-file blob $GIT_PUSH_CERT >../push-cert
@@ -96,9 +91,8 @@ test_expect_success GPG 'no certificate for a signed push with no update' '
 
 test_expect_success GPG 'signed push sends push certificate' '
 	prepare_dst &&
-	mkdir -p dst/.git/hooks &&
 	git -C dst config receive.certnonceseed sekrit &&
-	write_script dst/.git/hooks/post-receive <<-\EOF &&
+	test_hook -C dst post-receive <<-\EOF &&
 	# discard the update list
 	cat >/dev/null
 	# record the push certificate
@@ -139,10 +133,9 @@ test_expect_success GPG 'signed push sends push certificate' '
 
 test_expect_success GPGSSH 'ssh signed push sends push certificate' '
 	prepare_dst &&
-	mkdir -p dst/.git/hooks &&
 	git -C dst config gpg.ssh.allowedSignersFile "${GPGSSH_ALLOWED_SIGNERS}" &&
 	git -C dst config receive.certnonceseed sekrit &&
-	write_script dst/.git/hooks/post-receive <<-\EOF &&
+	test_hook -C dst post-receive <<-\EOF &&
 	# discard the update list
 	cat >/dev/null
 	# record the push certificate
@@ -223,9 +216,8 @@ test_expect_success GPG 'inconsistent push options in signed push not allowed' '
 
 test_expect_success GPG 'fail without key and heed user.signingkey' '
 	prepare_dst &&
-	mkdir -p dst/.git/hooks &&
 	git -C dst config receive.certnonceseed sekrit &&
-	write_script dst/.git/hooks/post-receive <<-\EOF &&
+	test_hook -C dst post-receive <<-\EOF &&
 	# discard the update list
 	cat >/dev/null
 	# record the push certificate
@@ -273,9 +265,8 @@ test_expect_success GPG 'fail without key and heed user.signingkey' '
 test_expect_success GPGSM 'fail without key and heed user.signingkey x509' '
 	test_config gpg.format x509 &&
 	prepare_dst &&
-	mkdir -p dst/.git/hooks &&
 	git -C dst config receive.certnonceseed sekrit &&
-	write_script dst/.git/hooks/post-receive <<-\EOF &&
+	test_hook -C dst post-receive <<-\EOF &&
 	# discard the update list
 	cat >/dev/null
 	# record the push certificate
@@ -326,10 +317,9 @@ test_expect_success GPGSM 'fail without key and heed user.signingkey x509' '
 test_expect_success GPGSSH 'fail without key and heed user.signingkey ssh' '
 	test_config gpg.format ssh &&
 	prepare_dst &&
-	mkdir -p dst/.git/hooks &&
 	git -C dst config gpg.ssh.allowedSignersFile "${GPGSSH_ALLOWED_SIGNERS}" &&
 	git -C dst config receive.certnonceseed sekrit &&
-	write_script dst/.git/hooks/post-receive <<-\EOF &&
+	test_hook -C dst post-receive <<-\EOF &&
 	# discard the update list
 	cat >/dev/null
 	# record the push certificate

t/t7113-post-index-change-hook.sh

@@ -17,8 +17,7 @@ test_expect_success 'setup' '
 '
 
 test_expect_success 'test status, add, commit, others trigger hook without flags set' '
-	mkdir -p .git/hooks &&
-	write_script .git/hooks/post-index-change <<-\EOF &&
+	test_hook post-index-change <<-\EOF &&
 		if test "$1" -eq 1; then
 			echo "Invalid combination of flags passed to hook; updated_workdir is set." >testfailure
 			exit 1
@@ -63,7 +62,7 @@ test_expect_success 'test status, add, commit, others trigger hook without flags
 '
 
 test_expect_success 'test checkout and reset trigger the hook' '
-	write_script .git/hooks/post-index-change <<-\EOF &&
+	test_hook post-index-change <<-\EOF &&
 		if test "$1" -eq 1 && test "$2" -eq 1; then
 			echo "Invalid combination of flags passed to hook; updated_workdir and updated_skipworktree are both set." >testfailure
 			exit 1
@@ -106,7 +105,7 @@ test_expect_success 'test checkout and reset trigger the hook' '
 '
 
 test_expect_success 'test reset --mixed and update-index triggers the hook' '
-	write_script .git/hooks/post-index-change <<-\EOF &&
+	test_hook post-index-change <<-\EOF &&
 		if test "$1" -eq 1 && test "$2" -eq 1; then
 			echo "Invalid combination of flags passed to hook; updated_workdir and updated_skipworktree are both set." >testfailure
 			exit 1

t/t9001-send-email.sh

@@ -2288,9 +2288,7 @@ test_expect_success $PREREQ 'cmdline in-reply-to used with --no-thread' '
 '
 
 test_expect_success $PREREQ 'invoke hook' '
-	mkdir -p .git/hooks &&
-
-	write_script .git/hooks/sendemail-validate <<-\EOF &&
+	test_hook sendemail-validate <<-\EOF &&
 	# test that we have the correct environment variable, pwd, and
 	# argument
 	case "$GIT_DIR" in