type hints: Make the mypy cache more permanent, amended

It turned out that mypy is not loaded by COIN tests when
requirements_coin.txt is used. Also enforce mypy existence
in COIN to prevent further configuration errors.

As a drive-by, a new cache is used that is > 10% faster.

Task-number: PYSIDE-2846
Change-Id: I75a27cfd0cb0fb0d7cd44c2a121291af052b0d8f
Pick-to: 6.8 6.8.0
Reviewed-by: Cristian Maureira-Fredes <[email protected]>

Author: ctismer

requirements-coin.txt

@@ -10,4 +10,3 @@ importlib_metadata>=6
 tomli>=2.0.1
 wheel>=0.43.0
 platformdirs >= 2.6.2
-mypy>=1.11.2

requirements.txt

@@ -8,3 +8,4 @@ patchelf==0.17.2; sys_platform == 'linux'
 # 1.24.4 is the last version that supports Python 3.8
 numpy<1.25; python_version < '3.9'
 numpy==1.26.3; python_version >= '3.9'
+mypy[faster-cache]>=1.13.0

sources/pyside6/tests/pysidetest/mypy_correctness_test.py

@@ -22,8 +22,13 @@
 import PySide6
 from PySide6 import SKIP_MYPY_TEST
 
+qtest_env = os.environ.get("QTEST_ENVIRONMENT", "")
+is_ci = qtest_env == "ci"
+# When we are in COIN, we enforce mypy existence, to prevent misconfigurations.
+USE_MYPY = True if is_ci else HAVE_MYPY
 
-@unittest.skipIf(not HAVE_MYPY, "The mypy test was skipped because mypy is not installed")
+
+@unittest.skipIf(not USE_MYPY, "The mypy test was skipped because mypy is not installed")
 @unittest.skipIf(SKIP_MYPY_TEST, "The mypy test was disabled")
 class MypyCorrectnessTest(unittest.TestCase):
 
@@ -32,6 +37,8 @@ def setUp(self):
         self.build_dir = self.pyside_dir.parent.parent
         os.chdir(self.build_dir)
         self.project_dir = Path(__file__).resolve().parents[4]
+        # For safety about future changes, check that we are sitting above the sources dir.
+        self.assertTrue((self.project_dir / "sources").exists())
         # Check if the project dir can be written. If so, put the mypy cache there.
         test_fname = self.project_dir / ".tmp test writable"
         try:
@@ -44,6 +51,7 @@ def setUp(self):
             self.cache_dir = ".mypy_cache"  # This is the mypy default.
 
     def testMypy(self):
+        self.assertTrue(HAVE_MYPY)
         cmd = [sys.executable, "-m", "mypy", "--cache-dir", self.cache_dir, self.pyside_dir]
         time_pre = time.time()
         ret = subprocess.run(cmd, capture_output=True)