Basically, get this command to be happy and make run_checks.py happy
 $ mypy --strict --exclude '_test.py$' --exclude qemu_configs/ ./tools/testing/kunit/

Primarily the changes are
* add `-> None` return type annotations
* add all the missing argument type annotations

Previously, we had false positives from mypy in `main()`, see commit
09641f7c7d8f ("kunit: tool: surface and address more typing issues").
But after commit 2dc9d6ca52a4 ("kunit: kunit.py extract handlers")
refactored things, the variable name reuse mypy hated is gone.

Note: mypy complains we don't annotate the types the unused args in our
signal handler. That's silly.
But to make it happy, I've copy-pasted an appropriate annotation from
https://github.com/python/typing/discussions/1042#discussioncomment-2013595.

Reported-by: Johannes Berg <johannes.berg@intel.com>
Link: https://lore.kernel.org/linux-kselftest/9a172b50457f4074af41fe1dc8e55dcaf4795d7e.camel@sipsolutions.net/
Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

E.g. for subprocess.Popen, it can be opened in `text=True` mode where it
returns strings, or `text=False` where it returns bytes.
To differentiate, you can annotate types as `Popen[str]` or
`Popen[bytes]`.

This patch should add subscripts in all the places we were missing them.

Reported-by: Johannes Berg <johannes.berg@intel.com>
Link: https://lore.kernel.org/linux-kselftest/20230315105055.9b2be0153625.I7a2cb99b95dff216c0feed4604255275e0b156a7@changeid/
Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

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>

We're missing the `f` prefix to have python do string interpolation, so
we'd never end up printing what the actual "unexpected" error is.

Fixes: ee92ed38364e ("kunit: add run_checks.py script to validate kunit changes")
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>

This formalizes the checks KUnit maintainers have been running (or in
other cases: forgetting to run).

This script also runs them all in parallel to minimize friction (pytype
can be fairly slow, but not slower than running kunit.py).

Example output:
$ ./tools/testing/kunit/run_checks.py
Waiting on 4 checks (kunit_tool_test.py, kunit smoke test, pytype, mypy)...
kunit_tool_test.py: PASSED
mypy: PASSED
pytype: PASSED
kunit smoke test: PASSED

On failure or timeout (5 minutes), it'll dump out the stdout/stderr.
E.g. adding in a type-checking error:
  mypy: FAILED
  > kunit.py:54: error: Name 'nonexistent_function' is not defined
  > Found 1 error in 1 file (checked 8 source files)

mypy and pytype are two Python type-checkers and must be installed.
This file treats them as optional and will mark them as SKIPPED if not
installed.

This tool also runs `kunit.py run --kunitconfig=lib/kunit` to run
KUnit's own KUnit tests and to verify KUnit kernel code and kunit.py
play nicely together.

It uses --build_dir=kunit_run_checks so as not to clobber the default
build_dir, which helps make it faster by reducing the need to rebuild,
esp. if you're been passing in --arch instead of using UML.

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