test: require typeddict-item on both invalid MessageDict fixture lines

Author: clean6378-max-it

tests/test_message_dict_mypy.py

@@ -2,6 +2,7 @@
 
 from __future__ import annotations
 
+import re
 import subprocess
 import sys
 from pathlib import Path
@@ -11,6 +12,9 @@
 REPO_ROOT = Path(__file__).resolve().parent.parent
 MYPY_TYPES_DIR = REPO_ROOT / "tests" / "mypy_types"
 
+_INVALID_FIXTURE = "message_dict_invalid.py"
+_INVALID_ERROR_LINES = (6, 9)
+
 
 def _run_mypy_on(path: Path) -> subprocess.CompletedProcess[str]:
     return subprocess.run(
@@ -30,10 +34,15 @@ def _run_mypy_on(path: Path) -> subprocess.CompletedProcess[str]:
     )
 
 
+def _typeddict_item_error_lines(output: str, fixture_name: str) -> set[int]:
+    pattern = rf"{re.escape(fixture_name)}:(\d+): error:.*\[typeddict-item\]"
+    return {int(match.group(1)) for match in re.finditer(pattern, output)}
+
+
 @pytest.mark.parametrize(
     ("fixture_name", "should_pass"),
     [
-        ("message_dict_invalid.py", False),
+        (_INVALID_FIXTURE, False),
         ("message_dict_valid.py", True),
     ],
 )
@@ -44,4 +53,8 @@ def test_message_dict_mypy_fixtures(fixture_name: str, should_pass: bool) -> Non
         assert result.returncode == 0, output
     else:
         assert result.returncode != 0
-        assert "typeddict-item" in output
+        error_lines = _typeddict_item_error_lines(output, fixture_name)
+        assert error_lines >= set(_INVALID_ERROR_LINES), (
+            f"expected typeddict-item on lines {_INVALID_ERROR_LINES}, "
+            f"got {sorted(error_lines)}: {output}"
+        )