| #!/usr/bin/env vpython3 |
| # Copyright 2026 The Chromium Authors |
| # Use of this source code is governed by a BSD-style license that can be |
| # found in the LICENSE file. |
| |
| import os |
| import sys |
| import unittest |
| from unittest import mock |
| |
| # Add the directory containing the script to the path so we can import it |
| sys.path.append(os.path.dirname(os.path.realpath(__file__))) |
| import find_affected_coverage_guided_fuzzers |
| |
| |
| class FindAffectedCoverageGuidedFuzzersTest(unittest.TestCase): |
| |
| def setUp(self): |
| patcher = mock.patch('find_affected_coverage_guided_fuzzers.subprocess.run') |
| self.mock_subprocess_run = patcher.start() |
| self.addCleanup(patcher.stop) |
| |
| def get_calls_args(self, mock_obj): |
| return [' '.join(call.args[0]) for call in mock_obj.call_args_list] |
| |
| def _set_subprocess_run_side_effect(self, |
| git_diff_stdout='', |
| gn_refs_mapping=None): |
| |
| def fake_subprocess_run(command, **kwargs): |
| mock_result = mock.MagicMock() |
| mock_result.stdout = '' |
| if command[0] == 'git': |
| mock_result.stdout = git_diff_stdout |
| elif command[:2] == ['gn', 'refs']: |
| if gn_refs_mapping: |
| for k, v in gn_refs_mapping.items(): |
| if k in command: |
| mock_result.stdout = v |
| break |
| return mock_result |
| |
| self.mock_subprocess_run.side_effect = fake_subprocess_run |
| |
| def test_generate_gn_build_dir_default(self): |
| find_affected_coverage_guided_fuzzers.generate_gn_build_dir('out/test') |
| |
| expected_args_str = ( |
| find_affected_coverage_guided_fuzzers.gn_args_libfuzzer.replace( |
| '\n', ' ')) |
| self.assertEqual(self.get_calls_args(self.mock_subprocess_run), |
| [f'gn gen out/test --args={expected_args_str}']) |
| |
| def test_get_modified_files(self): |
| self.mock_subprocess_run.return_value.stdout = ( |
| 'file1.cc\nfile2.h\nfile3.txt\n') |
| files = find_affected_coverage_guided_fuzzers.get_modified_files() |
| self.assertEqual(files, ['file1.cc', 'file2.h']) |
| |
| def test_get_affected_fuzzers(self): |
| self._set_subprocess_run_side_effect( |
| gn_refs_mapping={ |
| '//file1.cc': '//fuzzer1:fuzzer1\n//fuzzer2:fuzzer2\n', |
| '//file2.cc': '//fuzzer2:fuzzer2\n' |
| }) |
| |
| modified_files = ['file1.cc', 'file2.cc', 'file3.cc'] |
| all_fuzzers = [ |
| '//fuzzer1:fuzzer1', '//fuzzer2:fuzzer2', '//fuzzer3:fuzzer3' |
| ] |
| |
| affected = find_affected_coverage_guided_fuzzers.get_affected_fuzzers( |
| modified_files, 'out/test', all_fuzzers) |
| |
| self.assertEqual(len(affected), 3) |
| self.assertEqual(affected['//file1.cc'], |
| ['//fuzzer1:fuzzer1', '//fuzzer2:fuzzer2']) |
| self.assertEqual(affected['//file2.cc'], ['//fuzzer2:fuzzer2']) |
| self.assertEqual(affected['//file3.cc'], []) |
| |
| # We expect 3 calls to gn refs, one for each modified file. |
| self.assertEqual(self.mock_subprocess_run.call_count, 3) |
| # The order is non-deterministic because it uses a ThreadPoolExecutor, |
| # so we just check that the calls happened with the right arguments. |
| call_args_files = { |
| call.split()[-1] |
| for call in self.get_calls_args(self.mock_subprocess_run) |
| } |
| self.assertEqual(call_args_files, |
| {'//file1.cc', '//file2.cc', '//file3.cc'}) |
| |
| def test_get_affected_fuzzers_with_exception(self): |
| |
| def fake_subprocess_run(command, **kwargs): |
| mock_result = mock.MagicMock() |
| mock_result.stdout = '' |
| if command[:2] == ['gn', 'refs']: |
| if '//file1.cc' in command: |
| mock_result.stdout = '//fuzzer1:fuzzer1\n' |
| elif '//file2.cc' in command: |
| subprocess_mod = find_affected_coverage_guided_fuzzers.subprocess |
| raise subprocess_mod.CalledProcessError(returncode=1, |
| cmd=command, |
| output='out', |
| stderr='err') |
| return mock_result |
| |
| self.mock_subprocess_run.side_effect = fake_subprocess_run |
| |
| modified_files = ['file1.cc', 'file2.cc'] |
| all_fuzzers = ['//fuzzer1:fuzzer1'] |
| |
| with self.assertLogs(level='WARNING') as cm: |
| affected = find_affected_coverage_guided_fuzzers.get_affected_fuzzers( |
| modified_files, 'out/test', all_fuzzers) |
| |
| self.assertEqual(len(affected), 2) |
| self.assertEqual(affected['//file1.cc'], ['//fuzzer1:fuzzer1']) |
| self.assertEqual(affected['//file2.cc'], []) |
| self.assertTrue( |
| any('Failed to find reverse deps for //file2.cc' in log |
| for log in cm.output)) |
| |
| def test_run_gn_command_success(self): |
| self.mock_subprocess_run.return_value.stdout = ( |
| 'target1\ntarget2\n\ntarget1\n') |
| result = find_affected_coverage_guided_fuzzers.run_gn_command( |
| ['refs', 'out/test']) |
| self.assertEqual(result, ['target1', 'target2', 'target1']) |
| self.assertEqual(self.get_calls_args(self.mock_subprocess_run), |
| ['gn refs out/test']) |
| |
| def test_run_gn_command_called_process_error(self): |
| self.mock_subprocess_run.side_effect = ( |
| find_affected_coverage_guided_fuzzers.subprocess.CalledProcessError( |
| returncode=1, cmd=['gn'], output='out', stderr='err')) |
| with self.assertLogs(level='ERROR') as cm: |
| with self.assertRaises( |
| find_affected_coverage_guided_fuzzers.subprocess.CalledProcessError): |
| find_affected_coverage_guided_fuzzers.run_gn_command( |
| ['refs', 'out/test']) |
| self.assertIn('Error running gn command', cm.output[0]) |
| |
| def test_run_gn_command_file_not_found_error(self): |
| self.mock_subprocess_run.side_effect = FileNotFoundError() |
| with self.assertLogs(level='ERROR') as cm: |
| with self.assertRaises(FileNotFoundError): |
| find_affected_coverage_guided_fuzzers.run_gn_command( |
| ['refs', 'out/test']) |
| self.assertIn("'gn' command not found", cm.output[0]) |
| |
| def test_find_all_fuzzer_targets(self): |
| self.mock_subprocess_run.return_value.stdout = '//fuzzer1:fuzzer1\n' |
| result = find_affected_coverage_guided_fuzzers.find_all_fuzzer_targets( |
| 'out/test') |
| self.assertEqual(result, ['//fuzzer1:fuzzer1']) |
| self.assertEqual(self.get_calls_args(self.mock_subprocess_run), [ |
| 'gn refs out/test //testing/libfuzzer:fuzzing_engine ' |
| '--all --type=executable --as=label -q' |
| ]) |
| |
| def test_find_reverse_deps(self): |
| self.mock_subprocess_run.return_value.stdout = '//target1:target1\n' |
| result = find_affected_coverage_guided_fuzzers.find_reverse_deps( |
| 'out/test', '//file1.cc') |
| self.assertEqual(result, ['//target1:target1']) |
| self.assertEqual(self.get_calls_args(self.mock_subprocess_run), |
| ['gn refs out/test --all --as=label -q //file1.cc']) |
| |
| def test_main_no_modified_files(self): |
| self.mock_subprocess_run.return_value.stdout = '' |
| with mock.patch('sys.argv', ['script.py', '--out-dir', 'out/test']): |
| self.assertEqual(find_affected_coverage_guided_fuzzers.main(), 0) |
| self.assertEqual(self.get_calls_args(self.mock_subprocess_run), |
| ['git diff --name-only --diff-filter=d HEAD~']) |
| |
| def test_main_no_fuzzers(self): |
| self._set_subprocess_run_side_effect(git_diff_stdout='file1.cc\n') |
| |
| with mock.patch('sys.argv', ['script.py', '--out-dir', 'out/test']): |
| with self.assertLogs(level='WARNING') as cm: |
| self.assertEqual(find_affected_coverage_guided_fuzzers.main(), 1) |
| self.assertIn('No fuzzer targets found', cm.output[0]) |
| |
| expected_args_str = ( |
| find_affected_coverage_guided_fuzzers.gn_args_libfuzzer.replace( |
| '\n', ' ')) |
| self.assertEqual(self.get_calls_args(self.mock_subprocess_run), [ |
| 'git diff --name-only --diff-filter=d HEAD~', |
| f'gn gen out/test --args={expected_args_str}', |
| 'gn refs out/test //testing/libfuzzer:fuzzing_engine ' |
| '--all --type=executable --as=label -q' |
| ]) |
| |
| def test_main_success(self): |
| self._set_subprocess_run_side_effect( |
| git_diff_stdout='file1.cc\n', |
| gn_refs_mapping={ |
| '//testing/libfuzzer:fuzzing_engine': '//fuzzer:fuzzer\n', |
| '//file1.cc': '//fuzzer:fuzzer\n' |
| }) |
| |
| with mock.patch('sys.argv', ['script.py', '--out-dir', 'out/test']): |
| # Redirect stdout to avoid printing during tests |
| with mock.patch('sys.stdout', new_callable=mock.MagicMock) as mock_stdout: |
| self.assertEqual(find_affected_coverage_guided_fuzzers.main(), 0) |
| |
| # Verify the printed JSON output is correct |
| import json |
| output_str = ''.join(call.args[0] |
| for call in mock_stdout.write.call_args_list) |
| output_data = json.loads(output_str) |
| self.assertEqual( |
| output_data, |
| {'affected_fuzzers': { |
| '//file1.cc': ['//fuzzer:fuzzer'] |
| }}) |
| |
| expected_args_str = ( |
| find_affected_coverage_guided_fuzzers.gn_args_libfuzzer.replace( |
| '\n', ' ')) |
| self.assertEqual(self.get_calls_args(self.mock_subprocess_run), [ |
| 'git diff --name-only --diff-filter=d HEAD~', |
| f'gn gen out/test --args={expected_args_str}', |
| 'gn refs out/test //testing/libfuzzer:fuzzing_engine ' |
| '--all --type=executable --as=label -q', |
| 'gn refs out/test --all --as=label -q //file1.cc' |
| ]) |
| |
| |
| if __name__ == '__main__': |
| unittest.main() |
