test-lib-functions: remove bug-inducing "diagnostics" helper param

Remove the optional "diagnostics" parameter of the
test_path_is_{file,dir,missing} functions.

We have a lot of uses of these functions, but the only legitimate use
of the diagnostics parameter is from when the functions themselves
were introduced in 2caf20c52b7 (test-lib: user-friendly alternatives
to test [-d|-f|-e], 2010-08-10).

But as the the rest of this diff demonstrates its presence did more to
silently introduce bugs in our tests. Fix such bugs in the tests added
in ae4e89e549b (gc: add --keep-largest-pack option, 2018-04-15), and
c04ba51739a (t6046: testcases checking whether updates can be skipped
in a merge, 2018-04-19).

Let's also assert that those functions are called with exactly one
parameter, a follow-up commit will add similar asserts to other
functions in test-lib-functions.sh that we didn't have existing misuse
of.

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

1 files changed, 6 insertions, 5 deletions

diff --git a/t/test-lib-functions.sh b/t/test-lib-functions.sh
index f228647c2b..109d1b548c 100644
--- a/t/test-lib-functions.sh
+++ b/t/test-lib-functions.sh
@@ -717,12 +717,12 @@ test_external_without_stderr () {
 }
 
 # debugging-friendly alternatives to "test [-f|-d|-e]"
-# The commands test the existence or non-existence of $1. $2 can be
-# given to provide a more precise diagnosis.
+# The commands test the existence or non-existence of $1
 test_path_is_file () {
+	test "$#" -ne 1 && BUG "1 param"
 	if ! test -f "$1"
 	then
-		echo "File $1 doesn't exist. $2"
+		echo "File $1 doesn't exist"
 		false
 	fi
 }
@@ -730,15 +730,16 @@ test_path_is_file () {
 test_path_is_dir () {
 	if ! test -d "$1"
 	then
-		echo "Directory $1 doesn't exist. $2"
+		echo "Directory $1 doesn't exist"
 		false
 	fi
 }
 
 test_path_exists () {
+	test "$#" -ne 1 && BUG "1 param"
 	if ! test -e "$1"
 	then
-		echo "Path $1 doesn't exist. $2"
+		echo "Path $1 doesn't exist"
 		false
 	fi
 }