Add a job to draft a Flutter application release

.github/workflows/draft-release-flutter.yml

@@ -0,0 +1,109 @@
+name: draft release / flutter
+
+on:
+  workflow_call:
+    inputs:
+      slug:
+        description: Asset slug name
+        required: true
+        type: string
+
+permissions:
+  contents: write
+
+jobs:
+  create_draft_release:
+    name: create draft release
+    runs-on: ubuntu-latest
+    outputs:
+      upload_url: ${{ steps.gh_release.outputs.upload_url }}
+      url: ${{ steps.gh_release.outputs.url }}
+    steps:
+      - name: Checkout source code
+        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8
+      - id: gh_release
+        name: Create a new GitHub draft release
+        uses: softprops/action-gh-release@a06a81a03ee405af7f2048a818ed3f03bbf83c7b
+        with:
+          draft: true
+          generate_release_notes: true
+      - name: Annotate workflow run with draft release URL
+        run: 'echo "### :shipit: Opened draft release for: [${{ inputs.slug }} ${{ github.ref_name }}](${{ steps.gh_release.outputs.url }})" >> "$GITHUB_STEP_SUMMARY"'
+
+  upload_release_assets:
+    name: upload release assets
+    needs:
+      - create_draft_release
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - command: flutter build apk
+          - command: flutter build apk --split-per-abi
+          - command: flutter build appbundle
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout source code
+        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8
+      - name: Set up Flutter
+        uses: subosito/flutter-action@fd55f4c5af5b953cc57a2be44cb082c8f6635e8e
+        with:
+          channel: stable
+          flutter-version-file: pubspec.yaml
+          cache: true
+      - name: Install dependencies
+        run: flutter pub get --enforce-lockfile
+      - name: Build release App Bundle
+        run: flutter build appbundle
+      - name: Build release APK
+        run: flutter build apk
+      - name: Stage assets + checksums
+        run: |
+          set -euo pipefail
+
+          slug='${{ inputs.slug }}'
+          if [[ -z $slug ]]; then
+            echo "ERROR: inputs.slug is required and must be non-empty." >&2
+            exit 2
+          fi
+
+          if [[ '${{ github.ref_type }}' != 'tag' ]]; then
+            echo "ERROR: This workflow must be invoked from a tag ref." >&2
+            echo "       ref_type='${{ github.ref_type }}' ref='${{ github.ref }}'" >&2
+            exit 2
+          fi
+
+          tag='${{ github.ref_name }}'
+          if [[ -z $tag ]]; then
+            echo "ERROR: github.ref_name was empty; expected a tag name." >&2
+            exit 2
+          fi
+
+          dist_dir="dist"
+          mkdir -p -- "$dist_dir"
+
+          aab_src="build/app/outputs/bundle/release/app-release.aab"
+          apk_src="build/app/outputs/flutter-apk/app-release.apk"
+          [[ -f "$aab_src" ]] || { echo "ERROR: AAB not found at $aab_src" >&2; exit 2; }
+          [[ -f "$apk_src" ]] || { echo "ERROR: APK not found at $apk_src" >&2; exit 2; }
+
+          aab_dst="${dist_dir}/${slug}-${tag}.aab"
+          apk_dst="${dist_dir}/${slug}-${tag}.apk"
+
+          cp -v -- "$aab_src" "$aab_dst"
+          cp -v -- "$apk_src" "$apk_dst"
+
+          pushd "$dist_dir" >/dev/null
+          sha256sum -- *.aab *.apk > sha256sums.txt
+          popd >/dev/null
+
+          echo "Prepared assets:"
+          printf '  %s\n' "$apk_dst" "$aab_dst" "${dist_dir}/sha256sums.txt"
+
+      - name: Uploading release assets
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          echo "Uploading assets to: ${{ needs.create_draft_release.outputs.upload_url }}"
+          gh release upload "$GITHUB_REF_NAME" dist/* --clobber
+          echo ":arrow_up: Uploaded release assets" >>"$GITHUB_STEP_SUMMARY"