Sane use of test_expect_failure

Originally, test_expect_failure was designed to be the opposite
of test_expect_success, but this was a bad decision.  Most tests
run a series of commands that leads to the single command that
needs to be tested, like this:

    test_expect_{success,failure} 'test title' '
	setup1 &&
        setup2 &&
        setup3 &&
        what is to be tested
    '

And expecting a failure exit from the whole sequence misses the
point of writing tests.  Your setup$N that are supposed to
succeed may have failed without even reaching what you are
trying to test.  The only valid use of test_expect_failure is to
check a trivial single command that is expected to fail, which
is a minority in tests of Porcelain-ish commands.

This large-ish patch rewrites all uses of test_expect_failure to
use test_expect_success and rewrites the condition of what is
tested, like this:

    test_expect_success 'test title' '
	setup1 &&
        setup2 &&
        setup3 &&
        ! this command should fail
    '

test_expect_failure is redefined to serve as a reminder that
that test *should* succeed but due to a known breakage in git it
currently does not pass.  So if git-foo command should create a
file 'bar' but you discovered a bug that it doesn't, you can
write a test like this:

    test_expect_failure 'git-foo should create bar' '
        rm -f bar &&
        git foo &&
        test -f bar
    '

This construct acts similar to test_expect_success, but instead
of reporting "ok/FAIL" like test_expect_success does, the
outcome is reported as "FIXED/still broken".

Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 12 insertions, 12 deletions

diff --git a/t/t1400-update-ref.sh b/t/t1400-update-ref.sh
index 71ab2dd0ee..78cd41245b 100755
--- a/t/t1400-update-ref.sh
+++ b/t/t1400-update-ref.sh
@@ -51,23 +51,23 @@ test_expect_success \
 	 test $B"' = $(cat .git/'"$m"')'
 rm -f .git/$m
 
-test_expect_failure \
-	'(not) create HEAD with old sha1' \
-	"git update-ref HEAD $A $B"
-test_expect_failure \
-	"(not) prior created .git/$m" \
-	"test -f .git/$m"
+test_expect_success '(not) create HEAD with old sha1' "
+	! git update-ref HEAD $A $B
+"
+test_expect_success "(not) prior created .git/$m" "
+	! test -f .git/$m
+"
 rm -f .git/$m
 
 test_expect_success \
 	"create HEAD" \
 	"git update-ref HEAD $A"
-test_expect_failure \
-	'(not) change HEAD with wrong SHA1' \
-	"git update-ref HEAD $B $Z"
-test_expect_failure \
-	"(not) changed .git/$m" \
-	"test $B"' = $(cat .git/'"$m"')'
+test_expect_success '(not) change HEAD with wrong SHA1' "
+	! git update-ref HEAD $B $Z
+"
+test_expect_success "(not) changed .git/$m" "
+	! test $B"' = $(cat .git/'"$m"')
+'
 rm -f .git/$m
 
 : a repository with working tree always has reflog these days...