Test source distributions outside the checkout

AI use: OpenAI Codex based on GPT-5 was used to investigate the artifact layout, draft the workflow and packaging changes, and plan validation. Automated validation included the full test suite. Personal human review and responsibility attestation are pending.

Author: ryux1

.github/workflows/tests.yml

@@ -92,23 +92,58 @@ jobs:
 
   test-distribution:
     name: Check built packages
+    permissions:
+      contents: read
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
+      with:
+        persist-credentials: false
     - name: Install uv and Python
       uses: astral-sh/setup-uv@20cfd1bf945f4377ade1205e4dbc17946fc9a30d # v10.0.1
       with:
         enable-cache: false
         version: "0.11.6"
     - name: Check the release files
       run: make test-dist
+    - name: Upload built packages
+      uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
+      with:
+        name: built-packages
+        path: dist/*
+
+  test-source-distribution:
+    name: Test source distribution
+    needs: test-distribution
+    permissions: {}
+    runs-on: ubuntu-latest
+    steps:
+    - name: Download built packages
+      uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8.0.1
+      with:
+        name: built-packages
+        path: dist
+    - name: Install uv and Python 3.14
+      uses: astral-sh/setup-uv@20cfd1bf945f4377ade1205e4dbc17946fc9a30d # v10.0.1
+      with:
+        enable-cache: false
+        version: "0.11.6"
+        python-version: "3.14"
+    - name: Unpack source distribution
+      run: |
+        mkdir source-distribution
+        tar --extract --gzip --file dist/*.tar.gz --directory source-distribution --strip-components=1
+    - name: Test source distribution
+      working-directory: source-distribution
+      run: uv run --group test pytest
 
   deploy-tag-to-pypi:
     # only deploy on tags, see https://stackoverflow.com/a/58478262/1320237
     if: startsWith(github.ref, 'refs/tags/v')
     needs:
     - run-tests
     - test-distribution
+    - test-source-distribution
     runs-on: ubuntu-latest
     # This environment stores the TWINE_USERNAME and TWINE_PASSWORD
     # see https://docs.github.com/en/actions/deployment/targeting-different-environments/using-environments-for-deployment
@@ -157,6 +192,7 @@ jobs:
     needs:
     - run-tests
     - test-distribution
+    - test-source-distribution
     runs-on: ubuntu-latest
     environment:
       name: github-release

news/1708.bugfix

@@ -0,0 +1 @@
+Source distributions now include all files required to run their test suite, and CI verifies them outside the repository checkout. I used OpenAI Codex based on GPT-5 to assist with this change. @ryux1

pyproject.toml

@@ -153,6 +153,7 @@ exclude = [
 # Tests for files included in the distribution reside here:
 # src/icalendar/tests/test_create_release.sh
 "funding.json" = "funding.json"
+"generate_windows_to_olson_mapping.py" = "generate_windows_to_olson_mapping.py"
 
 [tool.hatch.build.targets.wheel]
 packages = ["src/icalendar"]