Add type check results parsing unit tests

Author: Otto-AA

tests/test_type_checking.py

@@ -0,0 +1,113 @@
+from inline_snapshot import snapshot
+from mutmut.type_checking import parse_mypy_report, parse_pyrefly_report
+
+from pathlib import Path
+from mutmut.type_checking import TypeCheckingError
+
+
+def test_mypy_parsing():
+    mypy_output = [
+        {
+            "file": "src/type_checking/__init__.py",
+            "line": 40,
+            "column": 20,
+            "message": 'Incompatible types in assignment (expression has type "None", variable has type "str")',
+            "hint": None,
+            "code": "assignment",
+            "severity": "error",
+        },
+        {
+            "file": "src/type_checking/__init__.py",
+            "line": 73,
+            "column": 11,
+            "message": 'Unsupported left operand type for - ("str")',
+            "hint": None,
+            "code": "operator",
+            "severity": "error",
+        },
+        {
+            "file": "src/type_checking/__init__.py",
+            "line": 114,
+            "column": 4,
+            "message": "By default the bodies of untyped functions are not checked, consider using --check-untyped-defs",
+            "hint": None,
+            "code": "annotation-unchecked",
+            "severity": "note",
+        },
+    ]
+
+    result = parse_mypy_report(mypy_output)
+    _make_pahts_relative(result)
+
+    assert result == snapshot(
+        [
+            TypeCheckingError(
+                file_path=Path("src/type_checking/__init__.py"),
+                line_number=40,
+                error_description='Incompatible types in assignment (expression has type "None", variable has type "str")',
+            ),
+            TypeCheckingError(
+                file_path=Path("src/type_checking/__init__.py"),
+                line_number=73,
+                error_description='Unsupported left operand type for - ("str")',
+            ),
+        ]
+    )
+
+
+def test_pyrefly_parsing():
+    pyrefly_output = {
+        "errors": [
+            {
+                "line": 40,
+                "column": 21,
+                "stop_line": 40,
+                "stop_column": 25,
+                "path": "src/type_checking/__init__.py",
+                "code": -2,
+                "name": "bad-assignment",
+                "description": "`None` is not assignable to `str`",
+                "concise_description": "`None` is not assignable to `str`",
+                "severity": "error",
+            },
+            {
+                "line": 73,
+                "column": 12,
+                "stop_line": 73,
+                "stop_column": 25,
+                "path": "src/type_checking/__init__.py",
+                "code": -2,
+                "name": "unsupported-operation",
+                "description": "`-` is not supported between `str` and `Literal['2']`\n  Cannot find `__sub__` or `__rsub__`",
+                "concise_description": "`-` is not supported between `str` and `Literal['2']`",
+                "severity": "error",
+            },
+        ]
+    }
+
+    result = parse_pyrefly_report(pyrefly_output)
+    _make_pahts_relative(result)
+
+    assert result == snapshot(
+        [
+            TypeCheckingError(
+                file_path=Path("src/type_checking/__init__.py"),
+                line_number=40,
+                error_description="`None` is not assignable to `str`",
+            ),
+            TypeCheckingError(
+                file_path=Path("src/type_checking/__init__.py"),
+                line_number=73,
+                error_description="`-` is not supported between `str` and `Literal['2']`",
+            ),
+        ]
+    )
+
+
+def _make_pahts_relative(errors: list[TypeCheckingError]):
+    cwd = Path(".").resolve()
+    for error in errors:
+        # make sure that we mapped the relative paths to absolute paths
+        assert cwd in error.file_path.parents
+        # then convert it to relative path, so it's easy to use snapshot(...)
+        error.file_path = error.file_path.relative_to(cwd)