test cibuildwheel wheels in Docker on Windows

.github/workflows/wheels.yml

@@ -140,12 +140,23 @@ jobs:
         env:
           CIBW_ARCHS: ${{ matrix.cibw_arch }}
           CIBW_BEFORE_ALL: "{package}\\winbuild\\build\\build_dep_all.cmd"
+          CIBW_CACHE_PATH: "C:\\cibw"
           CIBW_TEST_SKIP: "*-win_arm64"
           CIBW_TEST_COMMAND: >-
-            reg.exe add "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\python.exe" /v "GlobalFlag" /t REG_SZ /d "0x02000000" /f &&
-            cd /d {project} &&
-            python.exe selftest.py &&
-            python.exe -m pytest -vx -W always Tests
+            docker run -it --rm
+            -v {project}:C:\pillow
+            -v C:\cibw:C:\cibw
+            -v %CD%\..\venv-test:%CD%\..\venv-test
+            -e CI -e GITHUB_ACTIONS
+            mcr.microsoft.com/windows/servercore:ltsc2022
+            cmd /v:on /c
+            call %CD%\..\venv-test\Scripts\activate.bat ^&^&
+            reg add "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\python.exe" /v "GlobalFlag" /t REG_SZ /d "0x02000000" /f ^&^&
+            python --version ^&^&
+            cd /d C:\pillow ^&^&
+            path C:\pillow\winbuild\build\bin;!path! ^&^&
+            python selftest.py ^&^&
+            python -m pytest -vx -W always Tests Tests\check_wheel.py
         shell: cmd
       - uses: actions/upload-artifact@v3
         with:

Tests/check_wheel.py

@@ -0,0 +1,34 @@
+import sys
+
+import pytest
+
+from PIL import features
+
+
+@pytest.mark.skipif(sys.platform != "win32", reason="requires Windows")
+def test_windows_wheel_modules():
+    expected_modules = ["pil", "freetype2", "littlecms2", "webp"]
+
+    assert features.get_supported_modules() == expected_modules
+
+
+@pytest.mark.skipif(sys.platform != "win32", reason="requires Windows")
+def test_windows_wheel_codecs():
+    expected_codecs = ["jpg", "jpg_2000", "zlib", "libtiff"]
+
+    assert features.get_supported_codecs() == expected_codecs
+
+
+@pytest.mark.skipif(sys.platform != "win32", reason="requires Windows")
+def test_windows_wheel_features():
+    expected_features = [
+        "webp_anim",
+        "webp_mux",
+        "transp_webp",
+        "raqm",
+        "fribidi",
+        "harfbuzz",
+        "libjpeg_turbo",
+    ]
+
+    assert features.get_supported_features() == expected_features

Tests/helper.py

@@ -5,6 +5,7 @@
 import logging
 import os
 import shutil
+import subprocess
 import sys
 import sysconfig
 import tempfile
@@ -258,11 +259,19 @@ def hopper(mode=None, cache={}):
 
 
 def djpeg_available():
-    return bool(shutil.which("djpeg"))
+    try:
+        subprocess.check_call(["djpeg", "-version"])
+        return True
+    except subprocess.CalledProcessError:
+        return False
 
 
 def cjpeg_available():
-    return bool(shutil.which("cjpeg"))
+    try:
+        subprocess.check_call(["cjpeg", "-version"])
+        return True
+    except subprocess.CalledProcessError:
+        return False
 
 
 def netpbm_available():

Tests/test_imagegrab.py

@@ -15,6 +15,8 @@ class TestImageGrab:
         sys.platform not in ("win32", "darwin"), reason="requires Windows or macOS"
     )
     def test_grab(self):
+        if os.environ.get("USERNAME") == "ContainerAdministrator":
+            pytest.skip("can't grab screen when running in Docker")
         ImageGrab.grab()
         ImageGrab.grab(include_layered_windows=True)
         ImageGrab.grab(all_screens=True)

pyproject.toml

@@ -79,7 +79,7 @@ version = {attr = "PIL.__version__"}
 
 [tool.cibuildwheel]
 before-all = ".github/workflows/wheels-dependencies.sh"
-config-settings = "raqm=enable raqm=vendor fribidi=vendor"
+config-settings = "raqm=enable raqm=vendor fribidi=vendor imagequant=disable"
 test-command = "cd {project} && .github/workflows/wheels-test.sh"
 test-extras = "tests"