[clang-tools-extra] [clang-tidy] Implement alphabetical order test (PR #166072)

[Baranov Victor via cfe-commits]

================
@@ -0,0 +1,283 @@
+# 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
+
+# To run these tests:
+# python3 check-alphabetical-order_test.py -v
+
+import io
+import os
+import tempfile
+import unittest
+from contextlib import redirect_stderr
+import importlib.util
+import importlib.machinery
+from typing import Any, cast
+
+
+def _load_script_module():
+    here = os.path.dirname(cast(str, __file__))
+    script_path = os.path.normpath(os.path.join(here, "check-alphabetical-order.py"))
+    loader = importlib.machinery.SourceFileLoader(
+        "check_alphabetical_order", cast(str, script_path)
+    )
+    spec = importlib.util.spec_from_loader(loader.name, loader)
+    if spec is None or spec.loader is None:
+        raise ImportError(f"Failed to load spec for {script_path}")
+    mod = importlib.util.module_from_spec(spec)
+    spec.loader.exec_module(mod)
+    return mod
+
+
+_mod = cast(Any, _load_script_module())
+
+
+class TestAlphabeticalOrderCheck(unittest.TestCase):
+    def test_normalize_list_rst_sorts_rows(self):
+        lines = [
+            "Header\n",
+            "------" "\n",
+            ".. csv-table:: Clang-Tidy checks\n",
+            '   :header: "Name", "Offers fixes"\n',
+            "\n",
+            '   :doc:`bugprone-virtual-near-miss <bugprone/virtual-near-miss>`, "Yes"\n',
+            "   :doc:`cert-flp30-c <cert/flp30-c>`,\n",
+            '   :doc:`abseil-cleanup-ctad <abseil/cleanup-ctad>`, "Yes"\n',
+            "   A non-doc row that should stay after docs\n",
+            "\n",
+            "Footer\n",
+        ]
+
+        out = _mod.normalize_list_rst(lines)
+        pos_abseil = out.find("abseil-cleanup-ctad")
+        pos_bugprone = out.find("bugprone-virtual-near-miss")
+        pos_cert = out.find("cert-flp30-c")
+        self.assertTrue(all(p != -1 for p in [pos_abseil, pos_bugprone, pos_cert]))
+        self.assertLess(pos_abseil, pos_bugprone)
+        self.assertLess(pos_bugprone, pos_cert)
+        # Non-doc row should remain after doc rows within the table region.
+        self.assertGreater(out.find("A non-doc row"), out.find("cert-flp30-c"))
+
+    def test_find_heading(self):
+        lines = [
+            "- Deprecated the :program:`clang-tidy` ``zircon`` module. All checks have been\n",
+            "  moved to the ``fuchsia`` module instead. The ``zircon`` module will be removed\n",
+            "  in the 24th release.\n",
+            "\n",
+            "New checks\n",
+            "^^^^^^^^^^\n",
+            "- New :doc:`bugprone-derived-method-shadowing-base-method\n",
+            "  <clang-tidy/checks/bugprone/derived-method-shadowing-base-method>` check.\n",
+        ]
+        idx = _mod.find_heading(lines, "New checks")
+        self.assertEqual(idx, 4)
+
+    def test_duplicate_detection_and_report(self):
+        # Ensure duplicate detection works properly when sorting is incorrect.
+        lines = [
+            "Changes in existing checks\n",
+            "^^^^^^^^^^^^^^^^^^^^^^^^^^\n",
+            "\n",
+            "- Improved :doc:`bugprone-easily-swappable-parameters\n",
+            "  <clang-tidy/checks/bugprone/easily-swappable-parameters>` check by\n",
+            "  correcting a spelling mistake on its option\n",
+            "  ``NamePrefixSuffixSilenceDissimilarityTreshold``.\n",
+            "\n",
+            "- Improved :doc:`bugprone-exception-escape\n",
+            "  <clang-tidy/checks/bugprone/exception-escape>` check's handling of lambdas:\n",
+            "  exceptions from captures are now diagnosed, exceptions in the bodies of\n",
+            "  lambdas that aren't actually invoked are not.\n",
+            "\n",
+            "- Improved :doc:`bugprone-easily-swappable-parameters\n",
+            "  <clang-tidy/checks/bugprone/easily-swappable-parameters>` check by\n",
+            "  correcting a spelling mistake on its option\n",
+            "  ``NamePrefixSuffixSilenceDissimilarityTreshold``.\n",
+            "\n",
+        ]
+        dups = _mod.find_duplicate_entries(lines, "Changes in existing checks")
+        # Expect one duplicate group for 'bugprone-easily-swappable-parameters' with two occurrences.
+        self.assertEqual(len(dups), 1)
+        key, occs = dups[0]
+        self.assertEqual(
+            key.strip(), "- Improved :doc:`bugprone-easily-swappable-parameters"
+        )
+        self.assertEqual(len(occs), 2)
+
+        report = _mod._emit_duplicate_report(lines, "Changes in existing checks")
+        self.assertIsInstance(report, str)
+        self.assertIn("Duplicate entries in 'Changes in existing checks':", report)
+        self.assertIn(
+            "-- Duplicate: - Improved :doc:`bugprone-easily-swappable-parameters",
+            report,
+        )
+        self.assertEqual(report.count("- At line "), 2)
+        self.assertIn("- At line 4:", report)
+        self.assertIn("- At line 14:", report)
----------------
vbvictor wrote:

Here also, match report as a whole chunk of text

https://github.com/llvm/llvm-project/pull/166072