Re: [PATCH 1/2] kunit: tool: Do not error on tests without test plans

[Daniel Latypov]

On Wed, Oct 20, 2021 at 11:28 PM David Gow <davidgow@xxxxxxxxxx> wrote:
>
> The (K)TAP spec encourages test output to begin with a 'test plan': a
> count of the number of tests being run of the form:
> 1..n
>
> However, some test suites might not know the number of subtests in
> advance (for example, KUnit's parameterised tests use a generator
> function). In this case, it's not possible to print the test plan in
> advance.
>
> kunit_tool already parses test output which doesn't contain a plan, but
> reports an error. Since we want to use nested subtests with KUnit
> paramterised tests, remove this error.
>
> Signed-off-by: David Gow <davidgow@xxxxxxxxxx>
> ---
>  tools/testing/kunit/kunit_parser.py    | 5 ++---
>  tools/testing/kunit/kunit_tool_test.py | 5 ++++-
>  2 files changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/tools/testing/kunit/kunit_parser.py b/tools/testing/kunit/kunit_parser.py
> index 3355196d0515..50ded55c168c 100644
> --- a/tools/testing/kunit/kunit_parser.py
> +++ b/tools/testing/kunit/kunit_parser.py
> @@ -340,8 +340,8 @@ def parse_test_plan(lines: LineStream, test: Test) -> bool:
>         """
>         Parses test plan line and stores the expected number of subtests in
>         test object. Reports an error if expected count is 0.
> -       Returns False and reports missing test plan error if fails to parse
> -       test plan.
> +       Returns False and sets expected_count to None if there is no valid test
> +       plan.
>
>         Accepted format:
>         - '1..[number of subtests]'
> @@ -356,7 +356,6 @@ def parse_test_plan(lines: LineStream, test: Test) -> bool:
>         match = TEST_PLAN.match(lines.peek())
>         if not match:
>                 test.expected_count = None
> -               test.add_error('missing plan line!')

This works well, but there's an edge case.

This patch means we no longer print an error when there are no test
cases in a subtest.
We relied on a check just a bit lower in this function.

Consider

$ ./tools/testing/kunit/kunit.py parse <<EOF
TAP version 14
1..1
  # Subtest: suite
  1..1
    # Subtest: case
  ok 1 - case
ok 1 - suite
EOF

This produces the following output (timestamps removed)

============================================================
==================== suite (1 subtest) =====================
=========================== case ===========================
====================== [PASSED] case =======================
====================== [PASSED] suite ======================
============================================================

Should we surface some sort of error here?


>                 return False
>         test.log.append(lines.pop())
>         expected_count = int(match.group(1))
> diff --git a/tools/testing/kunit/kunit_tool_test.py b/tools/testing/kunit/kunit_tool_test.py
> index 9c4126731457..bc8793145713 100755
> --- a/tools/testing/kunit/kunit_tool_test.py
> +++ b/tools/testing/kunit/kunit_tool_test.py
> @@ -191,7 +191,10 @@ class KUnitParserTest(unittest.TestCase):
>                         result = kunit_parser.parse_run_tests(
>                                 kunit_parser.extract_tap_lines(
>                                 file.readlines()))
> -               self.assertEqual(2, result.test.counts.errors)
> +               # A missing test plan is not an error.
> +               self.assertEqual(0, result.test.counts.errors)
> +               # All tests should be accounted for.
> +               self.assertEqual(10, result.test.counts.total())
>                 self.assertEqual(
>                         kunit_parser.TestStatus.SUCCESS,
>                         result.status)
> --
> 2.33.0.1079.g6e70778dc9-goog
>