[clang-tidy][NFC] Add a unittest for checking list.rst (#193134)

Follow up of #192228

clang-tools-extra/clang-tidy/tool/check_update_docs.py

@@ -0,0 +1,93 @@
+#!/usr/bin/env python3
+#
+# ===-----------------------------------------------------------------------===#
+#
+# Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+# See https://llvm.org/LICENSE.txt for license information.
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+#
+# ===-----------------------------------------------------------------------===#
+
+"""
+
+Clang-Tidy Check List Checker
+=============================
+
+This wrapper script runs `add_new_check.py --update-docs` on
+a temporary copy of clang-tools-extra/{clang-tidy,docs} and
+writes the generated docs/clang-tidy/checks/list.rst to the
+requested output path.
+"""
+
+import argparse
+import io
+import os
+import shutil
+import subprocess
+import sys
+import tempfile
+from typing import Final, Sequence
+
+
+EXTRA_DIR: Final = os.path.join(os.path.dirname(__file__), "../..")
+CLANG_TIDY_DIR: Final = os.path.join(EXTRA_DIR, "clang-tidy")
+DOCS_DIR: Final = os.path.join(EXTRA_DIR, "docs")
+LIST_DOC: Final = os.path.join(DOCS_DIR, "clang-tidy", "checks", "list.rst")
+
+
+def read_text(path: str) -> str:
+    with io.open(path, "r", encoding="utf-8") as f:
+        return f.read()
+
+
+def write_text(path: str, content: str) -> None:
+    with io.open(path, "w", encoding="utf-8", newline="") as f:
+        f.write(content)
+
+
+def generate_updated_list() -> str:
+    with tempfile.TemporaryDirectory() as td:
+        temp_root = os.path.join(td, "clang-tools-extra")
+        temp_clang_tidy_dir = os.path.join(temp_root, "clang-tidy")
+        temp_docs_dir = os.path.join(temp_root, "docs")
+
+        shutil.copytree(CLANG_TIDY_DIR, temp_clang_tidy_dir)
+        shutil.copytree(DOCS_DIR, temp_docs_dir)
+
+        subprocess.run(
+            [
+                sys.executable,
+                os.path.join(temp_clang_tidy_dir, "add_new_check.py"),
+                "--update-docs",
+            ],
+            cwd=temp_clang_tidy_dir,
+            check=True,
+            stdout=subprocess.PIPE,
+            stderr=subprocess.STDOUT,
+            text=True,
+        )
+
+        return read_text(
+            os.path.join(temp_docs_dir, "clang-tidy", "checks", "list.rst")
+        )
+
+
+def main(argv: Sequence[str]) -> int:
+    ap = argparse.ArgumentParser()
+    ap.add_argument("-o", "--output", dest="out", required=True)
+    args = ap.parse_args(argv)
+
+    generated = generate_updated_list()
+    write_text(args.out, generated)
+
+    if read_text(LIST_DOC) != generated:
+        sys.stderr.write(
+            "\n'clang-tools-extra/docs/clang-tidy/checks/list.rst' is out of date.\n"
+            "Fix it by running 'clang-tools-extra/clang-tidy/add_new_check.py --update-docs'.\n\n"
+        )
+
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main(sys.argv[1:]))

clang-tools-extra/test/clang-tidy/infrastructure/update-checks-list.test

@@ -0,0 +1,2 @@
+// RUN: %python %S/../../../clang-tidy/tool/check_update_docs.py -o %t.clang-tidy-checks-list.rst
+// RUN: diff --strip-trailing-cr %S/../../../docs/clang-tidy/checks/list.rst %t.clang-tidy-checks-list.rst