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, 26 insertions, 4 deletions

diff --git a/t/test-lib.sh b/t/test-lib.sh
index 142540e1b1..9a3c0b4cad 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -139,6 +139,8 @@ fi
 
 test_failure=0
 test_count=0
+test_fixed=0
+test_broken=0
 
 trap 'echo >&5 "FATAL: Unexpected exit with code $?"; exit 1' exit
 
@@ -171,6 +173,17 @@ test_failure_ () {
 	test "$immediate" = "" || { trap - exit; exit 1; }
 }
 
+test_known_broken_ok_ () {
+	test_count=$(expr "$test_count" + 1)
+	test_fixed=$(($test_fixed+1))
+	say_color "" "  FIXED $test_count: $@"
+}
+
+test_known_broken_failure_ () {
+	test_count=$(expr "$test_count" + 1)
+	test_broken=$(($test_broken+1))
+	say_color skip "  still broken $test_count: $@"
+}
 
 test_debug () {
 	test "$debug" = "" || eval "$1"
@@ -211,13 +224,13 @@ test_expect_failure () {
 	error "bug in the test script: not 2 parameters to test-expect-failure"
 	if ! test_skip "$@"
 	then
-		say >&3 "expecting failure: $2"
+		say >&3 "checking known breakage: $2"
 		test_run_ "$2"
-		if [ "$?" = 0 -a "$eval_ret" != 0 -a "$eval_ret" -lt 129 ]
+		if [ "$?" = 0 -a "$eval_ret" = 0 ]
 		then
-			test_ok_ "$1"
+			test_known_broken_ok_ "$1"
 		else
-			test_failure_ "$@"
+		    test_known_broken_failure_ "$1"
 		fi
 	fi
 	echo >&3 ""
@@ -274,6 +287,15 @@ test_create_repo () {
 
 test_done () {
 	trap - exit
+
+	if test "$test_fixed" != 0
+	then
+		say_color pass "fixed $test_fixed known breakage(s)"
+	fi
+	if test "$test_broken" != 0
+	then
+		say_color error "still have $test_broken known breakage(s)"
+	fi
 	case "$test_failure" in
 	0)
 		# We could: