Major fixes and new features

venv/lib/python3.12/site-packages/mypy/test/meta/test_parse_data.py

@@ -0,0 +1,103 @@
+"""
+A "meta test" which tests the parsing of .test files. This is not meant to become exhaustive
+but to ensure we maintain a basic level of ergonomics for mypy contributors.
+"""
+import subprocess
+import sys
+import textwrap
+import uuid
+from pathlib import Path
+
+from mypy.test.config import test_data_prefix
+from mypy.test.helpers import Suite
+
+
+class ParseTestDataSuite(Suite):
+    def _dedent(self, s: str) -> str:
+        return textwrap.dedent(s).lstrip()
+
+    def _run_pytest(self, data_suite: str) -> str:
+        p_test_data = Path(test_data_prefix)
+        p_root = p_test_data.parent.parent
+        p = p_test_data / f"check-meta-{uuid.uuid4()}.test"
+        assert not p.exists()
+        try:
+            p.write_text(data_suite)
+            test_nodeid = f"mypy/test/testcheck.py::TypeCheckSuite::{p.name}"
+            args = [sys.executable, "-m", "pytest", "-n", "0", "-s", test_nodeid]
+            proc = subprocess.run(args, cwd=p_root, capture_output=True, check=False)
+            return proc.stdout.decode()
+        finally:
+            p.unlink()
+
+    def test_parse_invalid_case(self) -> None:
+        # Arrange
+        data = self._dedent(
+            """
+            [case abc]
+            s: str
+            [case foo-XFAIL]
+            s: str
+            """
+        )
+
+        # Act
+        actual = self._run_pytest(data)
+
+        # Assert
+        assert "Invalid testcase id 'foo-XFAIL'" in actual
+
+    def test_parse_invalid_section(self) -> None:
+        # Arrange
+        data = self._dedent(
+            """
+            [case abc]
+            s: str
+            [unknownsection]
+            abc
+            """
+        )
+
+        # Act
+        actual = self._run_pytest(data)
+
+        # Assert
+        expected_lineno = data.splitlines().index("[unknownsection]") + 1
+        expected = (
+            f".test:{expected_lineno}: Invalid section header [unknownsection] in case 'abc'"
+        )
+        assert expected in actual
+
+    def test_bad_ge_version_check(self) -> None:
+        # Arrange
+        data = self._dedent(
+            """
+            [case abc]
+            s: str
+            [out version>=3.8]
+            abc
+            """
+        )
+
+        # Act
+        actual = self._run_pytest(data)
+
+        # Assert
+        assert "version>=3.8 always true since minimum runtime version is (3, 8)" in actual
+
+    def test_bad_eq_version_check(self) -> None:
+        # Arrange
+        data = self._dedent(
+            """
+            [case abc]
+            s: str
+            [out version==3.7]
+            abc
+            """
+        )
+
+        # Act
+        actual = self._run_pytest(data)
+
+        # Assert
+        assert "version==3.7 always false since minimum runtime version is (3, 8)" in actual

venv/lib/python3.12/site-packages/mypy/test/meta/test_update_data.py

@@ -0,0 +1,157 @@
+"""
+A "meta test" which tests the `--update-data` feature for updating .test files.
+Updating the expected output, especially when it's in the form of inline (comment) assertions,
+can be brittle, which is why we're "meta-testing" here.
+"""
+import shlex
+import subprocess
+import sys
+import textwrap
+import uuid
+from pathlib import Path
+
+from mypy.test.config import test_data_prefix
+from mypy.test.helpers import Suite
+
+
+class UpdateDataSuite(Suite):
+    def _run_pytest_update_data(self, data_suite: str, *, max_attempts: int) -> str:
+        """
+        Runs a suite of data test cases through 'pytest --update-data' until either tests pass
+        or until a maximum number of attempts (needed for incremental tests).
+        """
+        p_test_data = Path(test_data_prefix)
+        p_root = p_test_data.parent.parent
+        p = p_test_data / f"check-meta-{uuid.uuid4()}.test"
+        assert not p.exists()
+        try:
+            p.write_text(textwrap.dedent(data_suite).lstrip())
+
+            test_nodeid = f"mypy/test/testcheck.py::TypeCheckSuite::{p.name}"
+            args = [sys.executable, "-m", "pytest", "-n", "0", "-s", "--update-data", test_nodeid]
+            cmd = shlex.join(args)
+            for i in range(max_attempts - 1, -1, -1):
+                res = subprocess.run(args, cwd=p_root)
+                if res.returncode == 0:
+                    break
+                print(f"`{cmd}` returned {res.returncode}: {i} attempts remaining")
+
+            return p.read_text()
+        finally:
+            p.unlink()
+
+    def test_update_data(self) -> None:
+        # Note: We test multiple testcases rather than 'test case per test case'
+        #       so we could also exercise rewriting multiple testcases at once.
+        actual = self._run_pytest_update_data(
+            """
+            [case testCorrect]
+            s: str = 42  # E: Incompatible types in assignment (expression has type "int", variable has type "str")
+
+            [case testWrong]
+            s: str = 42  # E: wrong error
+
+            [case testXfail-xfail]
+            s: str = 42  # E: wrong error
+
+            [case testWrongMultiline]
+            s: str = 42  # E: foo \
+                         # N: bar
+
+            [case testMissingMultiline]
+            s: str = 42;  i: int = 'foo'
+
+            [case testExtraneous]
+            s: str = 'foo'  # E: wrong error
+
+            [case testExtraneousMultiline]
+            s: str = 'foo'  # E: foo \
+                            # E: bar
+
+            [case testExtraneousMultilineNonError]
+            s: str = 'foo'  # W: foo \
+                            # N: bar
+
+            [case testOutCorrect]
+            s: str = 42
+            [out]
+            main:1: error: Incompatible types in assignment (expression has type "int", variable has type "str")
+
+            [case testOutWrong]
+            s: str = 42
+            [out]
+            main:1: error: foobar
+
+            [case testOutWrongIncremental]
+            s: str = 42
+            [out]
+            main:1: error: foobar
+            [out2]
+            main:1: error: foobar
+
+            [case testWrongMultipleFiles]
+            import a, b
+            s: str = 42  # E: foo
+            [file a.py]
+            s1: str = 42  # E: bar
+            [file b.py]
+            s2: str = 43  # E: baz
+            [builtins fixtures/list.pyi]
+            """,
+            max_attempts=3,
+        )
+
+        # Assert
+        expected = """
+        [case testCorrect]
+        s: str = 42  # E: Incompatible types in assignment (expression has type "int", variable has type "str")
+
+        [case testWrong]
+        s: str = 42  # E: Incompatible types in assignment (expression has type "int", variable has type "str")
+
+        [case testXfail-xfail]
+        s: str = 42  # E: wrong error
+
+        [case testWrongMultiline]
+        s: str = 42  # E: Incompatible types in assignment (expression has type "int", variable has type "str")
+
+        [case testMissingMultiline]
+        s: str = 42;  i: int = 'foo'  # E: Incompatible types in assignment (expression has type "int", variable has type "str") \\
+                                      # E: Incompatible types in assignment (expression has type "str", variable has type "int")
+
+        [case testExtraneous]
+        s: str = 'foo'
+
+        [case testExtraneousMultiline]
+        s: str = 'foo'
+
+        [case testExtraneousMultilineNonError]
+        s: str = 'foo'
+
+        [case testOutCorrect]
+        s: str = 42
+        [out]
+        main:1: error: Incompatible types in assignment (expression has type "int", variable has type "str")
+
+        [case testOutWrong]
+        s: str = 42
+        [out]
+        main:1: error: Incompatible types in assignment (expression has type "int", variable has type "str")
+
+        [case testOutWrongIncremental]
+        s: str = 42
+        [out]
+        main:1: error: Incompatible types in assignment (expression has type "int", variable has type "str")
+        [out2]
+        main:1: error: Incompatible types in assignment (expression has type "int", variable has type "str")
+
+        [case testWrongMultipleFiles]
+        import a, b
+        s: str = 42  # E: Incompatible types in assignment (expression has type "int", variable has type "str")
+        [file a.py]
+        s1: str = 42  # E: Incompatible types in assignment (expression has type "int", variable has type "str")
+        [file b.py]
+        s2: str = 43  # E: Incompatible types in assignment (expression has type "int", variable has type "str")
+        [builtins fixtures/list.pyi]
+        """
+        assert actual == textwrap.dedent(expected).lstrip()