Add GitHub Actions workflow for PyPI publishing

.github/workflows/publish.yml

@@ -0,0 +1,104 @@
+# Build and publish jsonpointer to PyPI when a GitHub release is published.
+#
+# Uses PyPI Trusted Publishing (OIDC), so no API token is stored in GitHub.
+#
+# One-time setup:
+#
+# 1. On PyPI, open https://pypi.org/manage/project/jsonpointer/settings/publishing/
+#    and add a GitHub trusted publisher with:
+#      Owner:             stefankoegl
+#      Repository name:   python-json-pointer
+#      Workflow name:     publish.yml
+#      Environment name:  pypi
+#
+# 2. In GitHub, go to Settings -> Environments -> New environment and create
+#    an environment named "pypi". Optionally add yourself as a required
+#    reviewer so every upload needs a manual approval, and restrict
+#    deployments to tags (e.g. "v*").
+#
+# 3. (Optional) Repeat steps 1 and 2 on https://test.pypi.org with the
+#    environment name "testpypi" to enable test uploads via manual runs.
+#
+# Releasing:
+#
+#   Bump __version__ in jsonpointer.py, commit, tag, push the tag, and publish
+#   a GitHub release for that tag. The workflow builds the sdist and wheel and
+#   uploads them to PyPI. Running the workflow manually ("Run workflow") uploads
+#   to TestPyPI instead.
+
+name: Publish to PyPI
+
+on:
+  release:
+    types: [published]
+  workflow_dispatch:
+
+jobs:
+  build:
+    name: Build distributions
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.13"
+
+      - name: Install build tools
+        run: |
+          python -m pip install --upgrade pip
+          pip install build twine
+
+      - name: Build sdist and wheel
+        run: python -m build
+
+      - name: Check distributions
+        run: twine check --strict dist/*
+
+      - uses: actions/upload-artifact@v4
+        with:
+          name: dist
+          path: dist/
+
+  publish-pypi:
+    name: Publish to PyPI
+    if: github.event_name == 'release'
+    needs: [build]
+    runs-on: ubuntu-latest
+    environment:
+      name: pypi
+      url: https://pypi.org/project/jsonpointer/
+    permissions:
+      id-token: write
+    steps:
+      - uses: actions/download-artifact@v4
+        with:
+          name: dist
+          path: dist/
+
+      - name: Publish to PyPI
+        uses: pypa/gh-action-pypi-publish@dc37677b2e1c63e2034f94d8a5b11f265b73ba33 # release/v1
+
+  publish-testpypi:
+    name: Publish to TestPyPI
+    if: github.event_name == 'workflow_dispatch'
+    needs: [build]
+    runs-on: ubuntu-latest
+    environment:
+      name: testpypi
+      url: https://test.pypi.org/project/jsonpointer/
+    permissions:
+      id-token: write
+    steps:
+      - uses: actions/download-artifact@v4
+        with:
+          name: dist
+          path: dist/
+
+      - name: Publish to TestPyPI
+        uses: pypa/gh-action-pypi-publish@release/v1
+        with:
+          repository-url: https://test.pypi.org/legacy/