verify-action-build: ignore IDE config dirs in vendored node_modules diff

utils/tests/verify_action_build/test_diff_node_modules.py

@@ -100,6 +100,69 @@ def test_noisy_files_ignored(self, tmp_path):
         )
         assert result is True
 
+    def test_ide_config_dirs_ignored(self, tmp_path):
+        # Some upstream npm packages ship author IDE config trees
+        # (``node_modules/tunnel/.idea/*`` was the case-in-point in
+        # benchmark-action's vendored deps).  These are not runtime code
+        # and shouldn't break verification when they leak into one side
+        # of the comparison and not the other.
+        orig = tmp_path / "original"
+        rebuilt = tmp_path / "rebuilt"
+        orig.mkdir()
+        rebuilt.mkdir()
+
+        (orig / "tunnel").mkdir()
+        (rebuilt / "tunnel").mkdir()
+        (orig / "tunnel" / "index.js").write_text("code")
+        (rebuilt / "tunnel" / "index.js").write_text("code")
+
+        # Only the rebuilt tree carries IDE files (the upstream package
+        # tarball includes them; the published vendored copy was scrubbed).
+        (rebuilt / "tunnel" / ".idea").mkdir()
+        (rebuilt / "tunnel" / ".idea" / "encodings.xml").write_text("<noise/>")
+        (rebuilt / "tunnel" / ".idea" / "modules.xml").write_text("<noise/>")
+        (rebuilt / "tunnel" / ".idea" / "node-tunnel.iml").write_text("<noise/>")
+        (rebuilt / "tunnel" / ".idea" / "workspace.xml").write_text("<noise/>")
+
+        # Mirror the same noise on the original side under a different
+        # package, just to be sure we filter symmetrically.
+        (orig / "lodash").mkdir()
+        (rebuilt / "lodash").mkdir()
+        (orig / "lodash" / "index.js").write_text("code")
+        (rebuilt / "lodash" / "index.js").write_text("code")
+        (orig / "lodash" / ".vscode").mkdir()
+        (orig / "lodash" / ".vscode" / "settings.json").write_text("{}")
+
+        result = diff_node_modules(
+            orig, rebuilt, "test", "repo", "a" * 40,
+        )
+        assert result is True
+
+    def test_other_dotdirs_in_packages_still_compared(self, tmp_path):
+        # Defensive: a non-IDE dot-directory inside a package that DOES
+        # carry meaningful content (``.bin``, ``.eslintrc``, etc.) must
+        # still be compared, not silently skipped.  Use ``.bin`` here
+        # since that's a real npm convention for package executables.
+        orig = tmp_path / "original"
+        rebuilt = tmp_path / "rebuilt"
+        orig.mkdir()
+        rebuilt.mkdir()
+
+        (orig / "pkg").mkdir()
+        (rebuilt / "pkg").mkdir()
+        (orig / "pkg" / "index.js").write_text("orig")
+        (rebuilt / "pkg" / "index.js").write_text("orig")
+        (orig / "pkg" / ".bin").mkdir()
+        (rebuilt / "pkg" / ".bin").mkdir()
+        (orig / "pkg" / ".bin" / "tool").write_text("ORIGINAL BINARY")
+        (rebuilt / "pkg" / ".bin" / "tool").write_text("DIFFERENT BINARY")
+
+        result = diff_node_modules(
+            orig, rebuilt, "test", "repo", "a" * 40,
+        )
+        # Content differs in .bin/tool — diff must still flag it.
+        assert result is False
+
     def test_package_json_install_fields_ignored(self, tmp_path):
         import json
         orig = tmp_path / "original"

utils/verify_action_build/diff_node_modules.py

@@ -32,9 +32,18 @@ def diff_node_modules(
     """Compare original vs rebuilt node_modules. Return True if they match."""
     blob_url = f"https://github.com/{org}/{repo}/blob/{commit_hash}/node_modules"
 
-    # Metadata files that legitimately differ between installs
+    # Metadata files that legitimately differ between installs.
     noisy_files = {".package-lock.json", ".yarn-integrity"}
-    noisy_dirs = {".cache", ".package-lock.json"}
+    # Directories that occasionally leak into a vendored ``node_modules`` (or
+    # into a fresh ``npm ci``) but are not meaningful for verification:
+    # npm's per-install ``.cache``/lock metadata, plus IDE config trees that
+    # some upstream npm packages ship — see
+    # ``node_modules/tunnel/.idea/*`` in benchmark-action's vendored deps —
+    # which are author tooling artifacts, not runtime code.
+    noisy_dirs = {
+        ".cache", ".package-lock.json",
+        ".idea", ".vscode", ".vs", ".fleet", ".zed",
+    }
 
     def collect_files(base: Path) -> dict[Path, str]:
         """Collect all files under base with their SHA256 hashes."""