kunit/kunit_tool_test: Test '--build_dir' option run

This commit adds kunit tool test for the '--build_dir' option.
Signed-off-by: SeongJae Park <sjpark@amazon.de>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Tested-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

tools/testing/kunit/kunit_tool_test.py

@@ -174,6 +174,7 @@ class KUnitMainTest(unittest.TestCase):
 		kunit.main(['run'], self.linux_source_mock)
 		assert self.linux_source_mock.build_reconfig.call_count == 1
 		assert self.linux_source_mock.run_kernel.call_count == 1
+		self.linux_source_mock.run_kernel.assert_called_once_with(build_dir='', timeout=300)
 		self.print_mock.assert_any_call(StrContains('Testing complete.'))
 
 	def test_run_passes_args_fail(self):
@@ -202,5 +203,12 @@ class KUnitMainTest(unittest.TestCase):
 		self.linux_source_mock.run_kernel.assert_called_once_with(build_dir='', timeout=timeout)
 		self.print_mock.assert_any_call(StrContains('Testing complete.'))
 
+	def test_run_builddir(self):
+		build_dir = '.kunit'
+		kunit.main(['run', '--build_dir', build_dir], self.linux_source_mock)
+		assert self.linux_source_mock.build_reconfig.call_count == 1
+		self.linux_source_mock.run_kernel.assert_called_once_with(build_dir=build_dir, timeout=300)
+		self.print_mock.assert_any_call(StrContains('Testing complete.'))
+
 if __name__ == '__main__':
 	unittest.main()