Add test PyPi action

Author: dcherian

.github/workflows/test-pypi-release.yaml

@@ -0,0 +1,90 @@
+name: Test PyPI build and upload
+on:
+  pull_request:
+    types: [opened, reopened, synchronize, labeled]
+  workflow_dispatch:
+
+jobs:
+  build-artifacts:
+    runs-on: ubuntu-latest
+    if: ${{ contains( github.event.pull_request.labels.*.name, 'Release') && github.event_name == 'pull_request' || github.event_name == 'workflow_dispatch'}}
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+      - uses: actions/setup-python@v5
+        name: Install Python
+        with:
+          python-version: "3.12"
+
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          python -m pip install build twine
+
+      - name: Build tarball and wheels
+        run: |
+          git clean -xdf
+          git restore -SW .
+          python -m build
+
+      - name: Check built artifacts
+        run: |
+          python -m twine check --strict dist/*
+          pwd
+          if [ -f dist/xarray-0.0.0.tar.gz ]; then
+            echo "❌ INVALID VERSION NUMBER"
+            exit 1
+          else
+            echo "✅ Looks good"
+          fi
+      - uses: actions/upload-artifact@v4
+        with:
+          name: releases
+          path: dist
+
+  test-built-dist:
+    needs: build-artifacts
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/setup-python@v5
+        name: Install Python
+        with:
+          python-version: "3.12"
+      - uses: actions/download-artifact@v4
+        with:
+          name: releases
+          path: dist
+      - name: List contents of built dist
+        run: |
+          ls -ltrh
+          ls -ltrh dist
+
+      - name: Verify the built dist/wheel is valid
+        if: github.event_name == 'push'
+        run: |
+          python -m pip install --upgrade pip
+          python -m pip install dist/xarray*.whl
+          python -m xarray.util.print_versions
+
+  upload-to-test-pypi:
+    needs: test-built-dist
+    runs-on: ubuntu-latest
+
+    environment:
+      name: pypi
+      url: https://test.pypi.org/p/xarray
+    permissions:
+      id-token: write
+
+    steps:
+      - uses: actions/download-artifact@v4
+        with:
+          name: releases
+          path: dist
+      - name: Publish package to TestPyPI
+        if: github.event_name == 'push'
+        uses: pypa/[email protected]
+        with:
+          repository_url: https://test.pypi.org/legacy/
+          verbose: true