Drop mypy self test (#5344)

Closes: #5303

.github/workflows/tests.yml

@@ -72,14 +72,6 @@ jobs:
       - run: pip install -U git+git://github.com/python/mypy
       - run: ./tests/mypy_test.py --platform=${{ matrix.platform }}
 
-  mypy-self-check:
-    name: Check mypy source with itself
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v2
-      - uses: actions/setup-python@v2
-      - run: ./tests/mypy_self_check.py
-
   mypy-test-suite:
     name: Run the mypy test suite
     # Ubuntu 20.04 doesn't have the Python 2 venv module.

README.md

@@ -110,8 +110,6 @@ tests typeshed with [mypy](https://github.com/python/mypy/)
 [pytype](https://github.com/google/pytype/).
 - `tests/pyright_test.py` tests typeshed with
 [pyright](https://github.com/microsoft/pyright).
-- `tests/mypy_self_check.py` checks mypy's code base using this version of
-typeshed.
 - `tests/mypy_test_suite.py` runs a subset of mypy's test suite using this version of
 typeshed.
 - `tests/check_consistent.py` checks certain files in typeshed remain
@@ -175,17 +173,7 @@ This test works similarly to `mypy_test.py`, except it uses `pytype`.
 
 This test requires Node.js to be installed.
 
-### mypy_self_check.py
-
-This test requires Python 3.6 or higher; Python 3.6.1 or higher is recommended.
-Run using:
-```
-(.venv3)$ python3 tests/mypy_self_check.py
-```
-
-This test checks mypy's code base using mypy and typeshed code in this repo.
-
-### mypy_test_suite.py
+### mypy\_test\_suite.py
 
 This test requires Python 3.5 or higher; Python 3.6.1 or higher is recommended.
 Run using:

tests/mypy_self_check.py

@@ -1,55 +0,0 @@
-#!/usr/bin/env python3
-"""Script to run mypy against its own code base."""
-
-import os
-import re
-import subprocess
-import sys
-import tempfile
-from pathlib import Path
-
-REQUIREMENTS_FILE = "requirements-tests-py3.txt"
-MYPY_REQUIREMENTS_REGEXPS = [r"^mypy[ =>]", r"^git\+.*/mypy.git\W"]
-
-
-def determine_mypy_version() -> str:
-    with open(REQUIREMENTS_FILE) as f:
-        for line in f:
-            for regexp in MYPY_REQUIREMENTS_REGEXPS:
-                m = re.match(regexp, line)
-                if m:
-                    return line.strip()
-    raise RuntimeError(f"no mypy version found in {REQUIREMENTS_FILE}")
-
-
-if __name__ == "__main__":
-    mypy_version = determine_mypy_version()
-
-    with tempfile.TemporaryDirectory() as tempdir:
-        dirpath = Path(tempdir)
-        subprocess.run(
-            ["git", "clone", "--depth", "1", "git://github.com/python/mypy", dirpath],
-            check=True,
-        )
-        os.environ["MYPYPATH"] = str(dirpath)
-        try:
-            subprocess.run([sys.executable, "-m", "pip", "install", "-U", mypy_version], check=True)
-            subprocess.run([sys.executable, "-m", "pip", "install", "-r", dirpath / "test-requirements.txt"], check=True)
-            subprocess.run(
-                [
-                    "mypy",
-                    "--config-file",
-                    dirpath / "mypy_self_check.ini",
-                    "--custom-typeshed-dir",
-                    ".",
-                    "-p", "mypy",
-                    "-p", "mypyc",
-                ],
-                check=True,
-            )
-        except subprocess.CalledProcessError as e:
-            print("mypy self test failed", file=sys.stderr)
-            sys.exit(e.returncode)
-        else:
-            print("mypy self test succeeded", file=sys.stderr)
-            sys.exit(0)