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>

tools/testing/kunit/kunit_kernel.py

@@ -11,6 +11,7 @@ import subprocess
 import os
 import shutil
 import signal
+from typing import Iterator
 
 from contextlib import ExitStack
 
@@ -39,7 +40,7 @@ class BuildError(Exception):
 class LinuxSourceTreeOperations(object):
 	"""An abstraction over command line operations performed on a source tree."""
 
-	def make_mrproper(self):
+	def make_mrproper(self) -> None:
 		try:
 			subprocess.check_output(['make', 'mrproper'], stderr=subprocess.STDOUT)
 		except OSError as e:
@@ -47,7 +48,7 @@ class LinuxSourceTreeOperations(object):
 		except subprocess.CalledProcessError as e:
 			raise ConfigError(e.output.decode())
 
-	def make_olddefconfig(self, build_dir, make_options):
+	def make_olddefconfig(self, build_dir, make_options) -> None:
 		command = ['make', 'ARCH=um', 'olddefconfig']
 		if make_options:
 			command.extend(make_options)
@@ -60,7 +61,7 @@ class LinuxSourceTreeOperations(object):
 		except subprocess.CalledProcessError as e:
 			raise ConfigError(e.output.decode())
 
-	def make_allyesconfig(self, build_dir, make_options):
+	def make_allyesconfig(self, build_dir, make_options) -> None:
 		kunit_parser.print_with_timestamp(
 			'Enabling all CONFIGs for UML...')
 		command = ['make', 'ARCH=um', 'allyesconfig']
@@ -82,7 +83,7 @@ class LinuxSourceTreeOperations(object):
 		kunit_parser.print_with_timestamp(
 			'Starting Kernel with all configs takes a few minutes...')
 
-	def make(self, jobs, build_dir, make_options):
+	def make(self, jobs, build_dir, make_options) -> None:
 		command = ['make', 'ARCH=um', '--jobs=' + str(jobs)]
 		if make_options:
 			command.extend(make_options)
@@ -100,7 +101,7 @@ class LinuxSourceTreeOperations(object):
 		if stderr:  # likely only due to build warnings
 			print(stderr.decode())
 
-	def linux_bin(self, params, timeout, build_dir):
+	def linux_bin(self, params, timeout, build_dir) -> None:
 		"""Runs the Linux UML binary. Must be named 'linux'."""
 		linux_bin = get_file_path(build_dir, 'linux')
 		outfile = get_outfile_path(build_dir)
@@ -110,23 +111,23 @@ class LinuxSourceTreeOperations(object):
 						   stderr=subprocess.STDOUT)
 			process.wait(timeout)
 
-def get_kconfig_path(build_dir):
+def get_kconfig_path(build_dir) -> str:
 	return get_file_path(build_dir, KCONFIG_PATH)
 
-def get_kunitconfig_path(build_dir):
+def get_kunitconfig_path(build_dir) -> str:
 	return get_file_path(build_dir, KUNITCONFIG_PATH)
 
-def get_outfile_path(build_dir):
+def get_outfile_path(build_dir) -> str:
 	return get_file_path(build_dir, OUTFILE_PATH)
 
 class LinuxSourceTree(object):
 	"""Represents a Linux kernel source tree with KUnit tests."""
 
-	def __init__(self):
+	def __init__(self) -> None:
 		self._ops = LinuxSourceTreeOperations()
 		signal.signal(signal.SIGINT, self.signal_handler)
 
-	def clean(self):
+	def clean(self) -> bool:
 		try:
 			self._ops.make_mrproper()
 		except ConfigError as e:
@@ -134,17 +135,17 @@ class LinuxSourceTree(object):
 			return False
 		return True
 
-	def create_kunitconfig(self, build_dir, defconfig=DEFAULT_KUNITCONFIG_PATH):
+	def create_kunitconfig(self, build_dir, defconfig=DEFAULT_KUNITCONFIG_PATH) -> None:
 		kunitconfig_path = get_kunitconfig_path(build_dir)
 		if not os.path.exists(kunitconfig_path):
 			shutil.copyfile(defconfig, kunitconfig_path)
 
-	def read_kunitconfig(self, build_dir):
+	def read_kunitconfig(self, build_dir) -> None:
 		kunitconfig_path = get_kunitconfig_path(build_dir)
 		self._kconfig = kunit_config.Kconfig()
 		self._kconfig.read_from_file(kunitconfig_path)
 
-	def validate_config(self, build_dir):
+	def validate_config(self, build_dir) -> bool:
 		kconfig_path = get_kconfig_path(build_dir)
 		validated_kconfig = kunit_config.Kconfig()
 		validated_kconfig.read_from_file(kconfig_path)
@@ -158,7 +159,7 @@ class LinuxSourceTree(object):
 			return False
 		return True
 
-	def build_config(self, build_dir, make_options):
+	def build_config(self, build_dir, make_options) -> bool:
 		kconfig_path = get_kconfig_path(build_dir)
 		if build_dir and not os.path.exists(build_dir):
 			os.mkdir(build_dir)
@@ -170,7 +171,7 @@ class LinuxSourceTree(object):
 			return False
 		return self.validate_config(build_dir)
 
-	def build_reconfig(self, build_dir, make_options):
+	def build_reconfig(self, build_dir, make_options) -> bool:
 		"""Creates a new .config if it is not a subset of the .kunitconfig."""
 		kconfig_path = get_kconfig_path(build_dir)
 		if os.path.exists(kconfig_path):
@@ -186,7 +187,7 @@ class LinuxSourceTree(object):
 			print('Generating .config ...')
 			return self.build_config(build_dir, make_options)
 
-	def build_um_kernel(self, alltests, jobs, build_dir, make_options):
+	def build_um_kernel(self, alltests, jobs, build_dir, make_options) -> bool:
 		try:
 			if alltests:
 				self._ops.make_allyesconfig(build_dir, make_options)
@@ -197,7 +198,7 @@ class LinuxSourceTree(object):
 			return False
 		return self.validate_config(build_dir)
 
-	def run_kernel(self, args=[], build_dir='', timeout=None):
+	def run_kernel(self, args=[], build_dir='', timeout=None) -> Iterator[str]:
 		args.extend(['mem=1G', 'console=tty'])
 		self._ops.linux_bin(args, timeout, build_dir)
 		outfile = get_outfile_path(build_dir)
@@ -206,6 +207,6 @@ class LinuxSourceTree(object):
 			for line in file:
 				yield line
 
-	def signal_handler(self, sig, frame):
+	def signal_handler(self, sig, frame) -> None:
 		logging.error('Build interruption occurred. Cleaning console.')
 		subprocess.call(['stty', 'sane'])