Merge branch 'zj/test-cred-helper-nicer-prove'

Minor improvement to t0303.

By Zbigniew Jędrzejewski-Szmek
* zj/test-cred-helper-nicer-prove:
  t0303: resurrect commit message as test documentation
  t0303: immediately bail out w/o GIT_TEST_CREDENTIAL_HELPER

t/t0303-credential-external.sh

@@ -1,39 +1,60 @@
 #!/bin/sh
 
-test_description='external credential helper tests'
-. ./test-lib.sh
-. "$TEST_DIRECTORY"/lib-credential.sh
+test_description='external credential helper tests
 
-pre_test() {
-	test -z "$GIT_TEST_CREDENTIAL_HELPER_SETUP" ||
-	eval "$GIT_TEST_CREDENTIAL_HELPER_SETUP"
+This is a tool for authors of external helper tools to sanity-check
+their helpers. If you have written the "git-credential-foo" helper,
+you check it with:
+
+  make GIT_TEST_CREDENTIAL_HELPER=foo t0303-credential-external.sh
+
+This assumes that your helper is capable of both storing and
+retrieving credentials (some helpers may be read-only, and they will
+fail these tests).
+
+Please note that the individual tests do not verify all of the
+preconditions themselves, but rather build on each other. A failing
+test means that tests later in the sequence can return false "OK"
+results.
+
+If your helper supports time-based expiration with a configurable
+timeout, you can test that feature with:
+
+  make GIT_TEST_CREDENTIAL_HELPER=foo \
+       GIT_TEST_CREDENTIAL_HELPER_TIMEOUT="foo --timeout=1" \
+       t0303-credential-external.sh
 
-	# clean before the test in case there is cruft left
-	# over from a previous run that would impact results
-	helper_test_clean "$GIT_TEST_CREDENTIAL_HELPER"
-}
+If your helper requires additional setup before the tests are started,
+you can set GIT_TEST_CREDENTIAL_HELPER_SETUP to a sequence of shell
+commands.
+'
 
-post_test() {
-	# clean afterwards so that we are good citizens
-	# and don't leave cruft in the helper's storage, which
-	# might be long-term system storage
-	helper_test_clean "$GIT_TEST_CREDENTIAL_HELPER"
-}
+. ./test-lib.sh
+. "$TEST_DIRECTORY"/lib-credential.sh
 
 if test -z "$GIT_TEST_CREDENTIAL_HELPER"; then
-	say "# skipping external helper tests (set GIT_TEST_CREDENTIAL_HELPER)"
-else
-	pre_test
-	helper_test "$GIT_TEST_CREDENTIAL_HELPER"
-	post_test
+	skip_all="used to test external credential helpers"
+	test_done
 fi
 
+test -z "$GIT_TEST_CREDENTIAL_HELPER_SETUP" ||
+	eval "$GIT_TEST_CREDENTIAL_HELPER_SETUP"
+
+# clean before the test in case there is cruft left
+# over from a previous run that would impact results
+helper_test_clean "$GIT_TEST_CREDENTIAL_HELPER"
+
+helper_test "$GIT_TEST_CREDENTIAL_HELPER"
+
 if test -z "$GIT_TEST_CREDENTIAL_HELPER_TIMEOUT"; then
-	say "# skipping external helper timeout tests"
+	say "# skipping timeout tests (GIT_TEST_CREDENTIAL_HELPER_TIMEOUT not set)"
 else
-	pre_test
 	helper_test_timeout "$GIT_TEST_CREDENTIAL_HELPER_TIMEOUT"
-	post_test
 fi
 
+# clean afterwards so that we are good citizens
+# and don't leave cruft in the helper's storage, which
+# might be long-term system storage
+helper_test_clean "$GIT_TEST_CREDENTIAL_HELPER"
+
 test_done