support PEP517

.github/test_files/setup.cfg

@@ -0,0 +1,6 @@
+# THIS IS A TEST FILE
+
+[metadata]
+name = test-project
+version = attr: .__version__
+description = This is a test project

.github/workflows/test.yml

@@ -35,6 +35,9 @@ jobs:
   test-stage-1:
     runs-on: ubuntu-latest
     timeout-minutes: 5
+    strategy:
+      matrix:
+        pep517: [true, false]
     steps:
     - name: Checkout repo
       uses: actions/checkout@v2
@@ -64,11 +67,15 @@ jobs:
         assert_equal "$HEAD_REF" 'prepare-9.2.3'
         assert_equal "$( git branch --show-current )" 'prepare-9.2.3'
 
-    - name: Setup mock __init__.py, setup.py & changelog files
+    - name: Setup mock project files
       run: |
         cp .github/test_files/__init__.py ./__init__.py
-        cp .github/test_files/setup.py ./setup.py
         cp .github/test_files/CHANGES.md ./CHANGES.md
+        if ${{ matrix.pep517 }}; then
+          cp .github/test_files/setup.cfg ./setup.cfg
+        else
+          cp .github/test_files/setup.py ./setup.py
+        fi
 
         echo "[command]git add ."; git add .
         echo "[command]git commit"
@@ -88,8 +95,15 @@ jobs:
         from __init__ import __version__
         assert __version__ == '9.2.3', f'::error:: assert version {__version__} == 9.2.3'
         "
-        setup_py_version='${{ steps.set-package-version.outputs.setup-py-version }}'
-        assert_equal "$setup_py_version" '1!9.2.3'
+        package_version='${{ steps.set-package-version.outputs.package-version }}'
+        # In setup.py projects, the __init__.py __version__ may be different to the setup.py version
+        # but in PEP 517 projects, the setup.cfg version will be the same as __init__.py __version__
+        if ${{ matrix.pep517 }}; then
+          expected_version="9.2.3"
+        else
+          expected_version="1!9.2.3"
+        fi
+        assert_equal "$package_version" "$expected_version"
         # Check changes to init file are staged
         exact_grep "M  __init__.py" <(git status -s)
 

build-python-package/action.yml

@@ -8,10 +8,19 @@ inputs:
 runs:
   using: composite
   steps:
-    - name: Install dependencies
-      shell: bash
-      run: python3 -m pip install wheel
-
     - name: Build
       shell: bash
-      run: python3 setup.py bdist_wheel sdist
+      run: |
+        if [[ -f setup.py ]]; then
+          # old style setup.py project
+          # (must manually install build dependencies)
+          echo "setup.py detected"
+          python3 -m pip install wheel
+          python3 setup.py bdist_wheel sdist
+        else
+          # PEP517 project
+          # (must install a builder, this installs build deps for us)
+          echo "PEP 517 project detected"
+          python3 -m pip install build
+          python3 -m build
+        fi

stage-1/set-python-package-version/action.yml

@@ -15,9 +15,9 @@ inputs:
     required: false
     default: true
 outputs:
-  setup-py-version:
+  package-version:
     description: Version number as outputted by setup.py (might be different from __init__.py, e.g. if epoch prefixed)
-    value: ${{ steps.get-setup-py-version.outputs.version }}
+    value: ${{ steps.get-package-version.outputs.version }}
 runs:
   using: composite
   steps:
@@ -53,21 +53,31 @@ runs:
           git add "$INIT_FILE"
         fi
 
-    - name: Get setup.py version
+    - name: Get package version
       # Might differ slightly from __init__.py, e.g. if epoch prefixed
-      id: get-setup-py-version
+      id: get-package-version
       shell: bash
       run: |
-        setup_py_version=$( python setup.py --version )
+        if [[ -f setup.py ]]; then
+          # get version from the setup.py for pre PEP517 projects
+          echo "setup.py detected"
+          package_version=$( python setup.py --version )
+        else
+          # shim to get the project version from a PEP517 project
+          echo "PEP 517 project detected"
+          echo 'from setuptools import setup; setup()' > setup.py
+          package_version=$( python setup.py --version )
+          rm setup.py
+        fi
         # Check version number is valid:
-        cmp_py_versions "$setup_py_version" "$setup_py_version"
-        echo "setup.py version: ${setup_py_version}"
-        echo "::set-output name=version::$setup_py_version"
+        cmp_py_versions "$package_version" "$package_version"
+        echo "package version: ${package_version}"
+        echo "::set-output name=version::$package_version"
 
     - name: Check version doesn't already exist on PyPI.org
       shell: bash
       working-directory: ${{ github.action_path }}
       env:
         PYPI_PACKAGE_NAME: ${{ inputs.pypi-package-name }}
-        SETUP_PY_VERSION: ${{ steps.get-setup-py-version.outputs.version }}
+        SETUP_PY_VERSION: ${{ steps.get-package-version.outputs.version }}
       run: node check-pypi.js

stage-2/comment-on-pr/comment-on-pr.js

@@ -41,8 +41,12 @@ You can still publish the dist to PyPI manually:
 
 (Make sure you have commit \`${pr_event.merge_commit_sha}\` checked out)
 \`\`\`shell
-# Create the build
+# Create the build (old style for setup.py projects)
 python3 setup.py bdist_wheel sdist
+
+# Create the build (PEP517)
+python -m build
+
 # Upload your build to PyPI
 twine upload dist/*
 \`\`\`