Add branch previews of the website with cleanup on merge/close

.github/workflows/ci.yml

@@ -2,9 +2,9 @@ name: Continuous Integration
 
 on:
   pull_request:
-    branches: ['**']
+    branches: ["**"]
   push:
-    branches: ['main']
+    branches: ["main"]
 
 jobs:
   build:
@@ -22,7 +22,27 @@ jobs:
           scala-cli-version: 1.12.2
       - run: scala-cli fmt --check .
       - run: scala-cli --server=false build.scala
-      - if: github.event_name != 'pull_request'
+      - name: Save PR number
+        if: github.event_name == 'pull_request'
+        run: echo "${{ github.event.pull_request.number }}" > pr_number.txt
+      - name: Upload site artifact
+        if: github.event_name == 'pull_request'
+        uses: actions/upload-artifact@v4
+        with:
+          name: site
+          path: target
+          if-no-files-found: error
+          retention-days: 30
+      - name: Upload PR number artifact
+        if: github.event_name == 'pull_request'
+        uses: actions/upload-artifact@v4
+        with:
+          name: pr-number
+          path: pr_number.txt
+          if-no-files-found: error
+          retention-days: 30
+      - name: Publish to GitHub Pages
+        if: github.event_name == 'push'
         uses: peaceiris/actions-gh-pages@v4.0.0
         with:
           github_token: ${{ secrets.GITHUB_TOKEN }}

.github/workflows/pr-preview-cleanup.yml

@@ -0,0 +1,50 @@
+name: Cleanup PR Preview
+
+on:
+  pull_request_target:
+    types: [closed]
+
+permissions:
+  contents: read
+
+env:
+  CLOUDFLARE_PAGES_PROJECT_NAME: typelevel-website
+  BRANCH_NAME: pr-${{ github.event.pull_request.number }}
+
+jobs:
+  cleanup-preview:
+    name: Delete Cloudflare Pages preview deployments
+    runs-on: ubuntu-latest
+    steps:
+      - name: Delete deployments for this PR's branch
+        env:
+          CLOUDFLARE_API_TOKEN: ${{ secrets.CLOUDFLARE_API_TOKEN }}
+          CLOUDFLARE_ACCOUNT_ID: ${{ secrets.CLOUDFLARE_ACCOUNT_ID }}
+        run: |
+          set -euo pipefail
+
+          API="https://api.cloudflare.com/client/v4/accounts/$CLOUDFLARE_ACCOUNT_ID/pages/projects/$CLOUDFLARE_PAGES_PROJECT_NAME/deployments"
+          AUTH_HEADER="Authorization: Bearer $CLOUDFLARE_API_TOKEN"
+
+          page=1
+          ids=()
+          while :; do
+            response=$(curl -sf -H "$AUTH_HEADER" "$API?page=$page&per_page=25")
+            count=$(echo "$response" | jq '.result | length')
+            [ "$count" -eq 0 ] && break
+            while IFS= read -r id; do
+              ids+=("$id")
+            done < <(echo "$response" | jq -r --arg branch "$BRANCH_NAME" \
+              '.result[] | select(.deployment_trigger.metadata.branch == $branch) | .id')
+            page=$((page + 1))
+          done
+
+          if [ ${#ids[@]} -eq 0 ]; then
+            echo "No preview deployments found for branch $BRANCH_NAME"
+            exit 0
+          fi
+
+          for id in "${ids[@]}"; do
+            echo "Deleting deployment $id"
+            curl -sf -X DELETE -H "$AUTH_HEADER" "$API/$id?force=true"
+          done

.github/workflows/pr-preview-deploy.yml

@@ -0,0 +1,46 @@
+name: Deploy PR Preview
+
+on:
+  workflow_run:
+    workflows: ["Continuous Integration"]
+    types: [completed]
+
+permissions:
+  actions: read
+  contents: read
+
+env:
+  CLOUDFLARE_PAGES_PROJECT_NAME: typelevel-website
+
+jobs:
+  deploy:
+    name: Publish to Cloudflare Pages
+    runs-on: ubuntu-latest
+    if: >
+      github.event.workflow_run.event == 'pull_request' &&
+      github.event.workflow_run.conclusion == 'success'
+    steps:
+      - name: Download site artifact
+        uses: actions/download-artifact@v4
+        with:
+          name: site
+          path: site
+          run-id: ${{ github.event.workflow_run.id }}
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+      - name: Download PR number artifact
+        uses: actions/download-artifact@v4
+        with:
+          name: pr-number
+          path: .
+          run-id: ${{ github.event.workflow_run.id }}
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+      - name: Read PR number
+        id: pr
+        run: echo "branch=pr-$(cat pr_number.txt)" >> "$GITHUB_OUTPUT"
+      - name: Deploy
+        uses: cloudflare/wrangler-action@v4
+        with:
+          apiToken: ${{ secrets.CLOUDFLARE_API_TOKEN }}
+          accountId: ${{ secrets.CLOUDFLARE_ACCOUNT_ID }}
+          gitHubToken: ${{ secrets.GITHUB_TOKEN }}
+          command: pages deploy ./site --project-name=${{ env.CLOUDFLARE_PAGES_PROJECT_NAME }} --branch=${{ steps.pr.outputs.branch }}