Add test

infra/cifuzz/affected_fuzz_targets.py

@@ -79,7 +79,7 @@ def remove_unaffected_fuzz_targets(project_name, out_dir, files_changed,
 
 
 def is_fuzz_target_affected(coverage_getter, fuzz_target_path, files_changed):
-  """Returns True if a fuzz target (|fuzz_target_path| is affected by
+  """Returns True if a fuzz target (|fuzz_target_path|) is affected by
   |files_changed|."""
   fuzz_target = os.path.basename(fuzz_target_path)
   covered_files = coverage_getter.get_files_covered_by_target(fuzz_target)

infra/cifuzz/affected_fuzz_targets_test.py

@@ -0,0 +1,74 @@
+# Copyright 2021 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""Tests for affected_fuzz_targets.py"""
+import os
+import shutil
+import tempfile
+import unittest
+from unittest import mock
+
+import parameterized
+
+import affected_fuzz_targets
+
+# pylint: disable=protected-access
+
+# NOTE: This integration test relies on
+# https://github.com/google/oss-fuzz/tree/master/projects/example project.
+EXAMPLE_PROJECT = 'example'
+
+EXAMPLE_FILE_CHANGED = 'test.txt'
+
+TEST_FILES_PATH = os.path.join(os.path.dirname(os.path.abspath(__file__)),
+                               'test_files')
+
+class RemoveUnaffectedFuzzTargets(unittest.TestCase):
+  """Tests remove_unaffected_fuzzers."""
+
+  TEST_FUZZER_1 = os.path.join(TEST_FILES_PATH, 'out', 'example_crash_fuzzer')
+  TEST_FUZZER_2 = os.path.join(TEST_FILES_PATH, 'out', 'example_nocrash_fuzzer')
+
+  # yapf: disable
+  @parameterized.parameterized.expand([
+      # Tests a specific affected fuzzers is kept.
+      ([[EXAMPLE_FILE_CHANGED], None], 2,),
+
+      # Tests specific affected fuzzer is kept.
+      ([[EXAMPLE_FILE_CHANGED], ['not/a/real/file']], 1),
+
+      # Tests all fuzzers are kept if none are deemed affected.
+      ([None, None], 2),
+
+      # Tests that multiple fuzzers are kept if multiple fuzzers are affected.
+      ([[EXAMPLE_FILE_CHANGED], [EXAMPLE_FILE_CHANGED]], 2),
+      ])
+  # yapf: enable
+  def test_remove_unaffected_fuzz_targets(self, side_effect, expected_dir_len):
+    """Tests that remove_unaffected_fuzzers has the intended effect."""
+    with tempfile.TemporaryDirectory() as tmp_dir, mock.patch(
+        'coverage._get_fuzzer_stats_dir_url', return_value=1):
+      with mock.patch(
+          'coverage.OssFuzzCoverageGetter.get_files_covered_by_target'
+      ) as mocked_get_files:
+        mocked_get_files.side_effect = side_effect
+        shutil.copy(self.TEST_FUZZER_1, tmp_dir)
+        shutil.copy(self.TEST_FUZZER_2, tmp_dir)
+        affected_fuzz_targets.remove_unaffected_fuzz_targets(
+            EXAMPLE_PROJECT, tmp_dir,
+            [EXAMPLE_FILE_CHANGED], '')
+        self.assertEqual(expected_dir_len, len(os.listdir(tmp_dir)))
+
+
+if __name__ == '__main__':
+  unittest.main()