Break out test and generated lines in branch line total (#13057)

* rm comments

* reduce comment

src/shared/generated-code-path.ts

@@ -0,0 +1,50 @@
+/**
+ * Path-only heuristic for "was this file written by a tool?", used to carve
+ * machine-authored lines out of the branch total. A regenerated lockfile or
+ * protobuf stub can dwarf every hand-written line in a branch, which is what
+ * makes a bare `+8,259` misleading.
+ *
+ * Conservative on purpose: a false positive understates the real work, so only
+ * names that are unambiguous across ecosystems are listed. Matched against the
+ * raw path with anchored regexes, for the reasons in `test-code-path.ts`.
+ */
+
+// Deliberately excludes `build`, `target`, `out` and `bin` — all common as
+// hand-written source directories.
+const GENERATED_DIRECTORY =
+  /(?:^|[/\\])(?:__generated__|__pycache__|\.next|\.nuxt|coverage|dist|generated|node_modules|vendor)[/\\]/i
+
+// Every dependency lockfile is regenerated wholesale, so its diff is churn
+// rather than authored change. Kept separate from the suffix alternation below
+// rather than merged into it: measured over 12.5k paths, two narrow anchored
+// regexes reject a non-match faster than one wide alternation.
+const LOCKFILE =
+  /(?:^|[/\\])(?:bun\.lockb?|cargo\.lock|composer\.lock|flake\.lock|gemfile\.lock|go\.sum|gradle\.lockfile|mix\.lock|npm-shrinkwrap\.json|package-lock\.json|packages\.lock\.json|pipfile\.lock|pnpm-lock\.yaml|poetry\.lock|pubspec\.lock|uv\.lock|yarn\.lock)$/i
+
+// The suffixes tools stamp onto their own output.
+const GENERATED_BASENAME = new RegExp(
+  `(?:${[
+    /\.(?:generated|designer)\.[^./\\]+/, // Foo.generated.ts, Form.Designer.cs
+    // Trailing segments are optional so plugin output keeps matching:
+    // service.pb.go, service_pb2.py, service.pb.gw.go, service.pb.validate.go.
+    /[._](?:pb|pb2|pb2_grpc)\.(?:[^./\\]+\.)*[^./\\]+/,
+    /[._]gen\.[^./\\]+/, // schema.gen.ts, mock_gen.go
+    /_generated\.[^./\\]+/, // bindings_generated.go
+    /\.(?:g|freezed)\.dart/, // model.g.dart
+    /\.min\.(?:js|css|mjs)/,
+    /\.(?:js|css|mjs)\.map/, // source maps
+    /\.snap/ // vitest/jest snapshots, rewritten by `-u`
+  ]
+    .map((pattern) => pattern.source)
+    .join('|')})$`,
+  'i'
+)
+
+/** Accepts POSIX and Windows separators — git reports `/`, callers may not. */
+export function isGeneratedCodePath(filePath: string): boolean {
+  return (
+    GENERATED_BASENAME.test(filePath) ||
+    LOCKFILE.test(filePath) ||
+    GENERATED_DIRECTORY.test(filePath)
+  )
+}