add succeeding test and failing test relevant to feature

Author: wyattscarpenter

mypy/test/meta/test_parse_data.py

@@ -67,3 +67,26 @@ def test_bad_eq_version_check(self) -> None:
         assert (
             "version==3.7 always false since minimum runtime version is (3, 10)" in actual.stdout
         )
+
+    def test_typical_error_comment(self) -> None:
+        # Act
+        actual = _run_pytest("""
+            [case abc]
+            a # E: typical-looking error comment
+            """)
+
+        # Assert
+        assert (
+            "typical-looking error comment" in actual.stderr
+        )
+    def test_lineleading_error_comment(self) -> None:
+        # Act
+        actual = _run_pytest("""
+            [case abc]
+            # E: line-leading error comment
+            """)
+
+        # Assert
+        assert (
+            "line-leading error comment" in actual.stderr
+        )