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, 20 insertions, 20 deletions

diff --git a/t/t7501-commit.sh b/t/t7501-commit.sh
index d1a415a12..21dcf550f 100755
--- a/t/t7501-commit.sh
+++ b/t/t7501-commit.sh
@@ -17,49 +17,49 @@ test_expect_success \
 	 git-add file && \
 	 git-status | grep 'Initial commit'"
 
-test_expect_failure \
+test_expect_success \
 	"fail initial amend" \
-	"git-commit --amend"
+	"! git-commit --amend"
 
 test_expect_success \
 	"initial commit" \
 	"git-commit -m initial"
 
-test_expect_failure \
+test_expect_success \
 	"invalid options 1" \
-	"git-commit -m foo -m bar -F file"
+	"! git-commit -m foo -m bar -F file"
 
-test_expect_failure \
+test_expect_success \
 	"invalid options 2" \
-	"git-commit -C HEAD -m illegal"
+	"! git-commit -C HEAD -m illegal"
 
-test_expect_failure \
+test_expect_success \
 	"using paths with -a" \
 	"echo King of the bongo >file &&
-	git-commit -m foo -a file"
+	! git-commit -m foo -a file"
 
-test_expect_failure \
+test_expect_success \
 	"using paths with --interactive" \
 	"echo bong-o-bong >file &&
-	echo 7 | git-commit -m foo --interactive file"
+	! echo 7 | git-commit -m foo --interactive file"
 
-test_expect_failure \
+test_expect_success \
 	"using invalid commit with -C" \
-	"git-commit -C bogus"
+	"! git-commit -C bogus"
 
-test_expect_failure \
+test_expect_success \
 	"testing nothing to commit" \
-	"git-commit -m initial"
+	"! git-commit -m initial"
 
 test_expect_success \
 	"next commit" \
 	"echo 'bongo bongo bongo' >file \
 	 git-commit -m next -a"
 
-test_expect_failure \
+test_expect_success \
 	"commit message from non-existing file" \
 	"echo 'more bongo: bongo bongo bongo bongo' >file && \
-	 git-commit -F gah -a"
+	 ! git-commit -F gah -a"
 
 # Empty except stray tabs and spaces on a few lines.
 sed -e 's/@$//' >msg <<EOF
@@ -68,9 +68,9 @@ sed -e 's/@$//' >msg <<EOF
   @
 Signed-off-by: hula
 EOF
-test_expect_failure \
+test_expect_success \
 	"empty commit message" \
-	"git-commit -F msg -a"
+	"! git-commit -F msg -a"
 
 test_expect_success \
 	"commit message from file" \
@@ -88,10 +88,10 @@ test_expect_success \
 	"amend commit" \
 	"VISUAL=./editor git-commit --amend"
 
-test_expect_failure \
+test_expect_success \
 	"passing -m and -F" \
 	"echo 'enough with the bongos' >file && \
-	 git-commit -F msg -m amending ."
+	 ! git-commit -F msg -m amending ."
 
 test_expect_success \
 	"using message from other commit" \