From 48b060cfa0e1b8b869f6cd6ac030d9d4a3a6de59 Mon Sep 17 00:00:00 2001
From: Sebastian Rittau <srittau@rittau.biz>
Date: Mon, 26 Apr 2021 12:51:28 +0200
Subject: [PATCH] mypy self check: Use mypy version from requirements file
 (#5245)

---
 requirements-tests-py3.txt |  2 ++
 tests/mypy_self_check.py   | 20 ++++++++++++++++----
 2 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/requirements-tests-py3.txt b/requirements-tests-py3.txt
index 9753eac9e..6038e56f9 100644
--- a/requirements-tests-py3.txt
+++ b/requirements-tests-py3.txt
@@ -1,3 +1,5 @@
+# Use the current mypy version until a version that supports modular
+# typeshed is released on PyPI.
 git+https://github.com/python/mypy.git@master
 typed-ast>=1.0.4
 black==20.8b1
diff --git a/tests/mypy_self_check.py b/tests/mypy_self_check.py
index 963279491..a0b23b1e0 100755
--- a/tests/mypy_self_check.py
+++ b/tests/mypy_self_check.py
@@ -2,17 +2,29 @@
 """Script to run mypy against its own code base."""
 
 import os
+import re
 import subprocess
 import sys
 import tempfile
 from pathlib import Path
 
-# Use the current mypy version until a version that supports modular
-# typeshed is released on PyPI.
-MYPY_VERSION = "git+git://github.com/python/mypy"
+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(
@@ -21,7 +33,7 @@ if __name__ == "__main__":
         )
         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", "-U", mypy_version], check=True)
             subprocess.run([sys.executable, "-m", "pip", "install", "-r", dirpath / "test-requirements.txt"], check=True)
             subprocess.run(
                 [