fix(node): exclude test fixtures from post-processing

Excludes `core/generator/gapic-generator-typescript/test-fixtures`
from directory traversal in `node_mono_repo.py` to prevent the
post-processor from re-adding them to `release-please-config.json`.

See googleapis/google-cloud-node#8171 for
an example of the issue.

Author: codyoss

synthtool/languages/node_mono_repo.py

@@ -482,6 +482,7 @@ def walk_through_owlbot_dirs(dir: Path, search_for_changed_files: bool):
     packages_to_exclude = [
         r"packages/gapic-node-processing/templates/bootstrap-templates",
         r"node_modules",
+        r"core/generator/gapic-generator-typescript/test-fixtures",
     ]
     if search_for_changed_files:
         try:

tests/test_node_mono_repo.py

@@ -509,6 +509,33 @@ def test_walk_through_owlbot_dirs_handwritten(mock_subproc_popen):
         assert any(re.search("handwritten/dlp", d) for d in owlbot_dirs)
 
 
+@patch("subprocess.run")
+def test_walk_through_owlbot_dirs_excluded(mock_subproc_popen):
+    process_mock = Mock()
+    attrs = {"communicate.return_value": ("output", "error")}
+    process_mock.configure_mock(**attrs)
+    mock_subproc_popen.return_value = process_mock
+
+    with util.copied_fixtures_dir(
+        FIXTURES / "nodejs_mono_repo_with_staging"
+    ) as workdir:
+        excluded_dir = workdir / "core" / "generator" / "gapic-generator-typescript" / "test-fixtures" / "speech"
+        excluded_dir.mkdir(parents=True)
+        (excluded_dir / ".OwlBot.yaml").touch()
+
+        regular_dir = workdir / "core" / "generator" / "gapic-generator-typescript"
+        regular_dir.mkdir(parents=True)
+        (regular_dir / ".OwlBot.yaml").touch()
+
+        owlbot_dirs = node_mono_repo.walk_through_owlbot_dirs(
+            workdir, search_for_changed_files=False
+        )
+
+        assert not mock_subproc_popen.called
+        assert any(re.search("core/generator/gapic-generator-typescript$", d) for d in owlbot_dirs)
+        assert not any(re.search("core/generator/gapic-generator-typescript/test-fixtures/speech", d) for d in owlbot_dirs)
+
+
 @patch("subprocess.run")
 def test_walk_through_owlbot_dirs_no_staging(mock_subproc_popen):
     process_mock = Mock()