Re: [PATCH] kunit: tool: fix extra trailing \n in parsed test output

[Daniel Latypov <dlatypov@google.com>]

On Thu, Oct 29, 2020 at 7:34 PM David Gow <davidgow@google.com> wrote:
>
> On Wed, Oct 21, 2020 at 7:32 AM Daniel Latypov <dlatypov@google.com> wrote:
> >
> > For simplcity, strip all trailing whitespace from parsed output.
> > I imagine no one is printing out meaningful trailing whitespace via
> > KUNIT_FAIL() or similar, and that if they are, they really shouldn't.
> >
> > At some point, the lines from `isolate_kunit_output()` started having
> > trailing \n, which results in artifacty output like this:
> >
> > $ ./tools/testing/kunit/kunit.py run
> > [16:16:46] [FAILED] example_simple_test
> > [16:16:46]     # example_simple_test: EXPECTATION FAILED at lib/kunit/kunit-example-test.c:29
> >
> > [16:16:46]     Expected 1 + 1 == 3, but
> >
> > [16:16:46]         1 + 1 == 2
> >
> > [16:16:46]         3 == 3
> >
> > [16:16:46]     not ok 1 - example_simple_test
> >
> > [16:16:46]
> >
> > After this change:
> > [16:16:46]     # example_simple_test: EXPECTATION FAILED at lib/kunit/kunit-example-test.c:29
> > [16:16:46]     Expected 1 + 1 == 3, but
> > [16:16:46]         1 + 1 == 2
> > [16:16:46]         3 == 3
> > [16:16:46]     not ok 1 - example_simple_test
> > [16:16:46]
> >
> > Signed-off-by: Daniel Latypov <dlatypov@google.com>
> > ---
>
> Thanks! This is a long-overdue fix, and it worked well for me.
>
> Tested-by: David Gow <davidgow@google.com>
>
> One comment below:
>
> >  tools/testing/kunit/kunit_parser.py | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/tools/testing/kunit/kunit_parser.py b/tools/testing/kunit/kunit_parser.py
> > index 8019e3dd4c32..e68b1c66a73f 100644
> > --- a/tools/testing/kunit/kunit_parser.py
> > +++ b/tools/testing/kunit/kunit_parser.py
> > @@ -342,7 +342,8 @@ def parse_run_tests(kernel_output) -> TestResult:
> >         total_tests = 0
> >         failed_tests = 0
> >         crashed_tests = 0
> > -       test_result = parse_test_result(list(isolate_kunit_output(kernel_output)))
> > +       test_result = parse_test_result(list(
> > +            l.rstrip() for l in isolate_kunit_output(kernel_output)))
>
> Could we do this inside isolate_kunit_output() instead? That seems
> like it'd be a more logical place for it (removing the newline is a
> sort of isolating the output), and it'd avoid making this line quite
> as horrifyingly nested.

Good point.
We could either do it on each yield (messy), or before, i.e.

diff --git a/tools/testing/kunit/kunit_parser.py
b/tools/testing/kunit/kunit_parser.py
index 8019e3dd4c32..14d35deb96cd 100644
--- a/tools/testing/kunit/kunit_parser.py
+++ b/tools/testing/kunit/kunit_parser.py
@@ -54,6 +54,7 @@ kunit_end_re = re.compile('(List of all partitions:|'
 def isolate_kunit_output(kernel_output):
        started = False
        for line in kernel_output:
+               line = line.rstrip()  # line always has a trailing \n
                if kunit_start_re.search(line):
                        prefix_len = len(line.split('TAP version')[0])
                        started = True

I had some vague concerns about this as
  kunit_start_re = re.compile(r'TAP version [0-9]+$')
has that anchor at the end.

This could ostensibly make it match more things than before.
Since I'm using rstrip() out of laziness, that means strings like
  '<prefix we allow for some reason>TAP version 42\t\n'
will now also match.

I don't really think that's an issue, but I'd sent this as a more
conservative change initially.
I can send the diff above as a replacement for this patch.

>
> >         if test_result.status == TestStatus.NO_TESTS:
> >                 print(red('[ERROR] ') + yellow('no tests run!'))
> >         elif test_result.status == TestStatus.FAILURE_TO_PARSE_TESTS:
> >
> > base-commit: c4d6fe7311762f2e03b3c27ad38df7c40c80cc93
> > --
> > 2.29.0.rc1.297.gfa9743e501-goog
> >