kunit: tool: misc cleanups

This primarily comes from running pylint over kunit tool code and
ignoring some warnings we don't care about.
If we ever got a fully clean setup, we could add this to run_checks.py,
but we're not there yet.

Fix things like
* Drop unused imports
* check `is None`, not `== None` (see PEP 8)
* remove redundant parens around returns
* remove redundant `else` / convert `elif` to `if` where appropriate
* rename make_arch_qemuconfig() param to base_kunitconfig (this is the
name used in the subclass, and it's a better one)
* kunit_tool_test: check the exit code for SystemExit (could be 0)

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: properly report the used arch for --json, or '' if not known

Before, kunit.py always printed "arch": "UM" in its json output, but...
1. With `kunit.py parse`, we could be parsing output from anywhere, so
we can't say that.
2. Capitalizing it is probably wrong, as it's `ARCH=um`
3. Commit 87c9c1631788 ("kunit: tool: add support for QEMU") made it so
kunit.py could knowingly run a different arch, yet we'd still always
claim "UM".

This patch addresses all of those. E.g.

1.
$ ./tools/testing/kunit/kunit.py parse .kunit/test.log --json | grep -o '"arch.*' | sort -u
"arch": "",

2.
$ ./tools/testing/kunit/kunit.py run --json | ...
"arch": "um",

3.
$ ./tools/testing/kunit/kunit.py run --json --arch=x86_64 | ...
"arch": "x86_64",

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: refactor how we plumb metadata into JSON

When using --json, kunit.py run/exec/parse will produce results in
KernelCI json format.
As part of that, we include the build_dir that was used, and we
(incorrectly) hardcode in the arch, etc.

We'll want a way to plumb more values (as well as the correct `arch`),
so this patch groups those fields into kunit_json.Metadata type.
This patch should have no user visible changes.

And since we only used build_dir in KunitParseRequest for json, we can
now move it out of that struct and add it into KunitExecRequest, which
needs it and used to get it via inheritance.

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: readability tweaks in KernelCI json generation logic

Use a more idiomatic check that a list is non-empty (`if mylist:`) and
simplify the function body by dedenting and using a dict to map between
the kunit TestStatus enum => KernelCI json status string.

The dict hopefully makes it less likely to have bugs like commit
9a6bb30a8830 ("kunit: tool: fix --json output for skipped tests").

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: simplify code since build_dir can't be None

--build_dir is set to a default of '.kunit' since commit ddbd60c779b4
("kunit: use --build_dir=.kunit as default"), but even before then it
was explicitly set to ''.

So outside of one unit test, there was no way for the build_dir to be
ever be None, and we can simplify code by fixing the unit test and
enforcing that via updated type annotations.

E.g. this lets us drop `get_file_path()` since it's now exactly
equivalent to os.path.join().

Note: there's some `if build_dir` checks that also fail if build_dir is
explicitly set to '' that just guard against passing "O=" to make.
But running `make O=` works just fine, so drop these checks.

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: make --json handling a bit clearer

Currently kunit_json.get_json_result() will output the JSON-ified test
output to json_path, but iff it's not "stdout".

Instead, move the responsibility entirely over to the one caller.

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: delete kunit_parser.TestResult type

The `log` field is unused, and the `status` field is accessible via
`test.status`.

So it's simpler to just return the main `Test` object directly.

And since we're no longer returning a namedtuple, which has no type
annotations, this hopefully means typecheckers are better equipped to
find any errors.

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: fix --json output for skipped tests

Currently, KUnit will report SKIPPED tests as having failed if one uses
--json.

Add the missing if statement to set the appropriate status ("SKIP").
See https://api.kernelci.org/schema-test-case.html:
"status": {
"type": "string",
"description": "The status of the execution of this test case",
"enum": ["PASS", "FAIL", "SKIP", "ERROR"],
"default": "PASS"
},
with this, we now can properly produce all four of the statuses.

Fixes: 5acaf6031f53 ("kunit: tool: Support skipped tests in kunit_tool")
Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: improve compatibility of kunit_parser with KTAP specification

Update to kunit_parser to improve compatibility with KTAP
specification including arbitrarily nested tests. Patch accomplishes
three major changes:

- Use a general Test object to represent all tests rather than TestCase
and TestSuite objects. This allows for easier implementation of arbitrary
levels of nested tests and promotes the idea that both test suites and test
cases are tests.

- Print errors incrementally rather than all at once after the
parsing finishes to maximize information given to the user in the
case of the parser given invalid input and to increase the helpfulness
of the timestamps given during printing. Note that kunit.py parse does
not print incrementally yet. However, this fix brings us closer to
this feature.

- Increase compatibility for different formats of input. Arbitrary levels
of nested tests supported. Also, test cases and test suites are now
supported to be present on the same level of testing.

This patch now implements the draft KTAP specification here:
https://lore.kernel.org/linux-kselftest/CA+GJov6tdjvY9x12JsJT14qn6c7NViJxqaJk+r-K1YJzPggFDQ@mail.gmail.com/
We'll update the parser as the spec evolves.

This patch adjusts the kunit_tool_test.py file to check for
the correct outputs from the new parser and adds a new test to check
the parsing for a KTAP result log with correct format for multiple nested
subtests (test_is_test_passed-all_passed_nested.log).

This patch also alters the kunit_json.py file to allow for arbitrarily
nested tests.

Signed-off-by: Rae Moar <rmoar@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: surface and address more typing issues

The authors of this tool were more familiar with a different
type-checker, https://github.com/google/pytype.

That's open source, but mypy seems more prevalent (and runs faster).
And unlike pytype, mypy doesn't try to infer types so it doesn't check
unanotated functions.

So annotate ~all functions in kunit tool to increase type-checking
coverage.
Note: per https://www.python.org/dev/peps/pep-0484/, `__init__()` should
be annotated as `-> None`.

Doing so makes mypy discover a number of new violations.
Exclude main() since we reuse `request` for the different types of
requests, which mypy isn't happy about.

This commit fixes all but one error, where `TestSuite.status` might be
None.

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Tested-by: Brendan Higgins <brendanhiggins@google.com>
Acked-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: allow generating test results in JSON

Add a --json flag, which when specified generates JSON formatted test
results conforming to the KernelCI API test_group spec[1]. The user can
use the new flag to specify a filename to print the json formatted
results to.

Link[1]: https://api.kernelci.org/schema-test-group.html#post
Signed-off-by: Heidi Fahim <heidifahim@google.com>
Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>