Publish branches to GH Pages

.github/workflows/ci.yml

@@ -27,15 +27,14 @@ jobs:
       - name: Debug info
         # https://docs.github.com/en/actions/reference/security/secure-use#use-an-intermediate-environment-variable
         env:
-          GH_HEAD_REF: ${{ github.head_ref }}
+          # `env:` values are printed to the log even without using them in `run:`
+          GH_CONTEXT: ${{ toJson(github) }}
         run: |
           cat <<EOF
-          Scratch environment: ${{ vars.SCRATCH_ENV || '<none>' }}
+          Working directory: $(pwd)
           Node version: $(node --version)
           NPM version: $(npm --version)
-          GitHub ref: ${{ github.ref }}
-          GitHub head ref: ${GH_HEAD_REF}
-          Working directory: $(pwd)
+          Scratch environment: ${{ vars.SCRATCH_ENV || '<none>' }}
           EOF
 
       - uses: dorny/paths-filter@de90cc6fb38fc0963ad72b210f1f284cd68cea36 # v3
@@ -87,11 +86,64 @@ jobs:
         with:
           package_name: ${{ matrix.package }}
 
+  preview:
+    runs-on: ubuntu-latest
+    needs: build
+    # We don't want to give forks free reign to publish to our GitHub Pages, so run this job only if both:
+    # - any workspace changed (otherwise there's no work to do)
+    # - and either
+    #   - this is not a PR (so it's some other event that happened in our fork, like a push or merge group)
+    #   - or it's a PR from our fork (not some other fork)
+    if: ${{
+        (needs.build.outputs.any-workspace == 'true') &&
+        (
+          (!github.event.pull_request) ||
+          (github.event.pull_request.head.repo.full_name == github.repository)
+        )
+      }}
+    name: Publish preview playgrounds to GitHub Pages
+    steps:
+      - name: Determine GitHub Pages directory name
+        id: branch_dir_name
+        run: |
+          if [ "$GITHUB_REF_NAME" == "develop" ]; then
+            echo "result=."
+          else
+            echo "result=${GITHUB_REF_NAME//[^A-Za-z0-9._-]/_}"
+          fi | tee --append "$GITHUB_OUTPUT"
+      - uses: actions/download-artifact@fa0a91b85d4f404e444e00e005971372dc801d16 # v4
+        with:
+          name: build
+          path: packages
+      - name: Prepare playgrounds for GitHub Pages
+        working-directory: ./packages
+        run: |
+          mkdir -p ../pages/
+          for pkg in *; do
+            if [ -d "${pkg}/playground" ]; then
+              # using symlinks is quick and artifact generation will dereference them
+              # if the GitHub Pages action stops dereferencing these links, we'll need to copy the files instead
+              ln -s "../packages/${pkg}/playground" "../pages/${pkg}"
+            fi
+          done
+
+          # scratch-gui doesn't follow the pattern above
+          ln -s "../packages/scratch-gui/build" "../pages/scratch-gui"
+
+          ls -l ../pages/
+      - name: Deploy playgrounds to GitHub Pages
+        uses: peaceiris/actions-gh-pages@4f9cc6602d3f66b9c108549d475ec49e8ef4d45e # v4
+        with:
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+          publish_dir: ./pages
+          destination_dir: "${{steps.branch_dir_name.outputs.result}}"
+          full_commit_message: "Build for ${{ github.sha }} ${{ github.event.head_commit.message }}"
+
   results:
-    name: Results
+    name: Test Results
     runs-on: ubuntu-latest
     needs: test
-    if: ${{ always() }}
+    if: ${{ !cancelled() }}
     steps:
       - run: |
           case "${{ needs.test.result }}" in

.github/workflows/ghpages-cleanup.yml

@@ -0,0 +1,29 @@
+name: GitHub Pages Cleanup
+
+on:
+  schedule:
+    - cron: 0 0 * * 6 # midnight on Saturdays
+  workflow_dispatch:
+
+jobs:
+  cleanup:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out GitHub Pages branch
+        uses: actions/checkout@v4
+        with:
+          # replace `fetch-depth` with `shallow-since` if and when actions/checkout#619 (or an equivalent) gets merged
+          fetch-depth: 0
+          ref: gh-pages
+      - name: Mark stale directories for removal
+        run: |
+          for dir in */; do
+            if [ -z "$(git log -n 1 --since "1 month ago" -- "$dir")" ]; then
+              git rm -r "$dir"
+            fi
+          done
+          git status
+      - name: Commit
+        run: "git commit -m 'chore: remove stale GitHub Pages branches'"
+      - name: Push
+        run: "git push"

.github/workflows/publish.yml

@@ -145,35 +145,3 @@ jobs:
         run: |
           git tag -f "${{github.event.release.tag_name}}" HEAD
           git push -f origin "refs/tags/${{github.event.release.tag_name}}"
-
-      - name: Deploy scratch-svg-renderer to GitHub Pages
-        uses: peaceiris/actions-gh-pages@4f9cc6602d3f66b9c108549d475ec49e8ef4d45e # v4
-        with:
-          github_token: ${{ secrets.GITHUB_TOKEN }}
-          publish_dir: ./packages/scratch-svg-renderer/playground
-          destination_dir: scratch-svg-renderer
-          full_commit_message: "Build for ${{ github.sha }} ${{ github.event.head_commit.message }}"
-
-      - name: Deploy scratch-render to GitHub Pages
-        uses: peaceiris/actions-gh-pages@4f9cc6602d3f66b9c108549d475ec49e8ef4d45e # v4
-        with:
-          github_token: ${{ secrets.GITHUB_TOKEN }}
-          publish_dir: ./packages/scratch-render/playground
-          destination_dir: scratch-render
-          full_commit_message: "Build for ${{ github.sha }} ${{ github.event.head_commit.message }}"
-
-      - name: Deploy scratch-vm to GitHub Pages
-        uses: peaceiris/actions-gh-pages@4f9cc6602d3f66b9c108549d475ec49e8ef4d45e # v4
-        with:
-          github_token: ${{ secrets.GITHUB_TOKEN }}
-          publish_dir: ./packages/scratch-vm/playground
-          destination_dir: scratch-vm
-          full_commit_message: "Build for ${{ github.sha }} ${{ github.event.head_commit.message }}"
-
-      - name: Deploy scratch-gui to GitHub Pages
-        uses: peaceiris/actions-gh-pages@4f9cc6602d3f66b9c108549d475ec49e8ef4d45e # v4
-        with:
-          github_token: ${{ secrets.GITHUB_TOKEN }}
-          publish_dir: ./packages/scratch-gui/build
-          destination_dir: scratch-gui
-          full_commit_message: "Build for ${{ github.sha }} ${{ github.event.head_commit.message }}"