Update hugo.toml

.github/workflows/build-and-preview-docs.yml

@@ -22,12 +22,16 @@ defaults:
   run:
     shell: bash
 
+env:
+  PREVIEW_RETENTION_LIMIT: 6
+
 jobs:
   build-and-deploy-preview:
     runs-on: ubuntu-24.04
+    outputs:
+      removed_prs_json: ${{ steps.prune-previews.outputs.removed_prs_json }}
     env:
       HUGO_VERSION: 0.157.0
-      PREVIEW_RETENTION_LIMIT: 6
 
     steps:
       - name: Checkout PR code
@@ -103,10 +107,12 @@ jobs:
           path: gh-pages-maintenance
 
       - name: Prune old PR previews
+        id: prune-previews
         if: github.event.action != 'closed'
         run: |
           cd gh-pages-maintenance
           mkdir -p pr-preview
+          removed_prs=()
 
           mapfile -t previews < <(
             while IFS= read -r preview; do
@@ -118,14 +124,18 @@ jobs:
           )
 
           if (( ${#previews[@]} <= PREVIEW_RETENTION_LIMIT )); then
+            echo "removed_prs_json=[]" >> "$GITHUB_OUTPUT"
             exit 0
           fi
 
           for preview in "${previews[@]:PREVIEW_RETENTION_LIMIT}"; do
             rm -rf "pr-preview/$preview"
+            removed_prs+=("${preview#pr-}")
           done
 
           if git diff --quiet -- pr-preview; then
+            echo "removed_prs=" >> "$GITHUB_OUTPUT"
+            echo "removed_prs_json=[]" >> "$GITHUB_OUTPUT"
             exit 0
           fi
 
@@ -135,6 +145,9 @@ jobs:
           git commit -m "Prune old PR previews"
           git push
 
+          echo "removed_prs=$(IFS=,; echo "${removed_prs[*]}")" >> "$GITHUB_OUTPUT"
+          echo "removed_prs_json=$(printf '%s\n' "${removed_prs[@]}" | jq -R . | jq -sc .)" >> "$GITHUB_OUTPUT"
+
       - name: Comment PR with Preview URL
         if: github.event.action != 'closed'
         uses: marocchino/sticky-pull-request-comment@v2
@@ -146,6 +159,57 @@ jobs:
             🌐 **Preview URL**: https://${{ github.repository_owner }}.github.io/${{ github.event.repository.name }}/pr-preview/pr-${{ github.event.pull_request.number }}/
 
             _This preview will be updated automatically when you push new commits to this PR._
+
+      - name: Comment on pruned previews
+        if: github.event.action != 'closed' && steps.prune-previews.outputs.removed_prs_json != '[]'
+        uses: actions/github-script@v7
+        env:
+          REMOVED_PRS_JSON: ${{ steps.prune-previews.outputs.removed_prs_json }}
+          PREVIEW_RETENTION_LIMIT: ${{ env.PREVIEW_RETENTION_LIMIT }}
+        with:
+          script: |
+            const removedPrs = JSON.parse(process.env.REMOVED_PRS_JSON);
+            const retentionLimit = process.env.PREVIEW_RETENTION_LIMIT;
+            const header = "pr-preview";
+            const marker = `<!-- Sticky Pull Request Comment${header} -->`;
+
+            for (const prNumber of removedPrs) {
+              const body =
+                `Preview deployment for PR #${prNumber} removed.\n\n` +
+                `This PR preview was automatically pruned because we keep only the ${retentionLimit} most recently updated previews on GitHub Pages to stay within deployment size limits.\n\n` +
+                `If needed, push a new commit to this PR to generate a fresh preview.\n` +
+                `${marker}`;
+
+              const { data: comments } = await github.rest.issues.listComments({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                issue_number: Number(prNumber),
+                per_page: 100,
+              });
+
+              const existingComment = [...comments].reverse().find((comment) =>
+                comment.user?.login === "github-actions[bot]" &&
+                comment.body?.includes(marker)
+              );
+
+              if (existingComment) {
+                await github.rest.issues.updateComment({
+                  owner: context.repo.owner,
+                  repo: context.repo.repo,
+                  comment_id: existingComment.id,
+                  body,
+                });
+                continue;
+              }
+
+              await github.rest.issues.createComment({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                issue_number: Number(prNumber),
+                body,
+              });
+            }
+
       - name: Cleanup PR preview on close
         if: github.event.action == 'closed'
         uses: rossjrw/pr-preview-action@v1.6.3

docs/hugo.toml

@@ -55,7 +55,7 @@ pygmentsStyle = "tango"
 [permalinks]
 blog = "/:section/:year/:month/:day/:slug/"
 
-# Image processing configuration.
+
 [imaging]
 resampleFilter = "CatmullRom"
 quality = 75