Major fixes and new features

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

@@ -0,0 +1,45 @@
+from __future__ import annotations
+
+import sys
+from io import StringIO
+
+import mypy.api
+from mypy.test.helpers import Suite
+
+
+class APISuite(Suite):
+    def setUp(self) -> None:
+        self.sys_stdout = sys.stdout
+        self.sys_stderr = sys.stderr
+        sys.stdout = self.stdout = StringIO()
+        sys.stderr = self.stderr = StringIO()
+
+    def tearDown(self) -> None:
+        sys.stdout = self.sys_stdout
+        sys.stderr = self.sys_stderr
+        assert self.stdout.getvalue() == ""
+        assert self.stderr.getvalue() == ""
+
+    def test_capture_bad_opt(self) -> None:
+        """stderr should be captured when a bad option is passed."""
+        _, stderr, _ = mypy.api.run(["--some-bad-option"])
+        assert isinstance(stderr, str)
+        assert stderr != ""
+
+    def test_capture_empty(self) -> None:
+        """stderr should be captured when a bad option is passed."""
+        _, stderr, _ = mypy.api.run([])
+        assert isinstance(stderr, str)
+        assert stderr != ""
+
+    def test_capture_help(self) -> None:
+        """stdout should be captured when --help is passed."""
+        stdout, _, _ = mypy.api.run(["--help"])
+        assert isinstance(stdout, str)
+        assert stdout != ""
+
+    def test_capture_version(self) -> None:
+        """stdout should be captured when --version is passed."""
+        stdout, _, _ = mypy.api.run(["--version"])
+        assert isinstance(stdout, str)
+        assert stdout != ""