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, 13 insertions, 13 deletions

diff --git a/t/t3210-pack-refs.sh b/t/t3210-pack-refs.sh
index 4ddc634..b64ccfb 100755
--- a/t/t3210-pack-refs.sh
+++ b/t/t3210-pack-refs.sh
@@ -39,12 +39,12 @@ test_expect_success \
      git show-ref b >result &&
      diff expect result'
 
-test_expect_failure \
-    'git branch c/d should barf if branch c exists' \
-    'git branch c &&
+test_expect_success 'git branch c/d should barf if branch c exists' '
+     git branch c &&
      git pack-refs --all &&
-     rm .git/refs/heads/c &&
-     git branch c/d'
+     rm -f .git/refs/heads/c &&
+     ! git branch c/d
+'
 
 test_expect_success \
     'see if a branch still exists after git pack-refs --prune' \
@@ -54,11 +54,11 @@ test_expect_success \
      git show-ref e >result &&
      diff expect result'
 
-test_expect_failure \
-    'see if git pack-refs --prune remove ref files' \
-    'git branch f &&
+test_expect_success 'see if git pack-refs --prune remove ref files' '
+     git branch f &&
      git pack-refs --all --prune &&
-     ls .git/refs/heads/f'
+     ! test -f .git/refs/heads/f
+'
 
 test_expect_success \
     'git branch g should work when git branch g/h has been deleted' \
@@ -69,11 +69,11 @@ test_expect_success \
      git pack-refs --all &&
      git branch -d g'
 
-test_expect_failure \
-    'git branch i/j/k should barf if branch i exists' \
-    'git branch i &&
+test_expect_success 'git branch i/j/k should barf if branch i exists' '
+     git branch i &&
      git pack-refs --all --prune &&
-     git branch i/j/k'
+     ! git branch i/j/k
+'
 
 test_expect_success \
     'test git branch k after branch k/l/m and k/lm have been deleted' \