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

[via cfe-commits]

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+# 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
+from typing import cast
+
+
+import check_alphabetical_order as _mod
+
+
+class TestAlphabeticalOrderCheck(unittest.TestCase):
+    def test_normalize_list_rst_sorts_rows(self):
+        input_lines = [
+            ".. 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",
+        ]
+
+        expected_lines = [
+            ".. csv-table:: Clang-Tidy checks\n",
+            '   :header: "Name", "Offers fixes"\n',
+            "\n",
+            '   :doc:`abseil-cleanup-ctad <abseil/cleanup-ctad>`, "Yes"\n',
+            '   :doc:`bugprone-virtual-near-miss <bugprone/virtual-near-miss>`, "Yes"\n',
+            "   :doc:`cert-flp30-c <cert/flp30-c>`,\n",
+            "   A non-doc row that should stay after docs\n",
+        ]
+
+        out_str = _mod.normalize_list_rst("".join(input_lines))
+        self.assertEqual(out_str, "".join(expected_lines))
+
+        out_lines = _mod.normalize_list_rst(input_lines)
+        self.assertEqual(out_lines, expected_lines)
+
+    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",
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zeyi2 wrote:

I added a new testcase for this, but I don't think the script can reorder the inner list for now. Do we need to handle that?

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