test-lib-functions: restrict test_must_fail usage

In previous commits, we removed the usage of test_must_fail() for most
commands except for a set of pre-approved commands. Since that's done,
only allow test_must_fail() to run those pre-approved commands.

Obviously, we should allow `git`.

We allow `__git*` as some completion functions return an error code that
comes from a git invocation. It's good to avoid using test_must_fail
unnecessarily but it wouldn't hurt to err on the side of caution when
we're potentially wrapping a git command (like in these cases).

We also allow `test-tool` and `test-svn-fe` because these are helper
commands that are written by us and we want to catch their failure.

Finally, we allow `test_terminal` because `test_terminal` just wraps
around git commands. Also, we cannot rewrite
`test_must_fail test_terminal` as `test_terminal test_must_fail` because
test_must_fail() is a shell function and as a result, it cannot be
invoked from the test-terminal Perl script.

We opted to explicitly list the above tools instead of using a catch-all
such as `test[-_]*` because we want to be as restrictive as possible so
that in the future, someone would not accidentally introduce an
unrelated usage of test_must_fail() on an "unapproved" command.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/t/t0000-basic.sh b/t/t0000-basic.sh
index 2ff176cd5d..90bf1dbc8d 100755
--- a/t/t0000-basic.sh
+++ b/t/t0000-basic.sh
@@ -1271,4 +1271,22 @@ test_expect_success 'very long name in the index handled sanely' '
 	test $len = 4098
 '
 
+test_expect_success 'test_must_fail on a failing git command' '
+	test_must_fail git notacommand
+'
+
+test_expect_success 'test_must_fail on a failing git command with env' '
+	test_must_fail env var1=a var2=b git notacommand
+'
+
+test_expect_success 'test_must_fail rejects a non-git command' '
+	! test_must_fail grep ^$ notafile 2>err &&
+	grep -F "test_must_fail: only '"'"'git'"'"' is allowed" err
+'
+
+test_expect_success 'test_must_fail rejects a non-git command with env' '
+	! test_must_fail env var1=a var2=b grep ^$ notafile 2>err &&
+	grep -F "test_must_fail: only '"'"'git'"'"' is allowed" err
+'
+
 test_done