Automatically sync backport changelog to issue (WordPress#62973)

Author: ellatrix

.github/workflows/check-backport-changelog.yml

@@ -18,22 +18,15 @@ on:
             - '!packages/e2e-tests/**'
 jobs:
     check:
-        name: Check CHANGELOG diff
+        name: Check for a Core backport changelog entry
         runs-on: ubuntu-latest
+        if: ${{ !contains(github.event.pull_request.labels.*.name, 'No Core Sync Required') && !contains(github.event.pull_request.labels.*.name, 'Backport from WordPress Core') }}
         steps:
-            - name: 'Get PR commit count'
-              run: echo "PR_COMMIT_COUNT=$(( ${{ github.event.pull_request.commits }} + 1 ))" >> "${GITHUB_ENV}"
-            - name: Checkout code
-              uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
+            - uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
               with:
                   ref: ${{ github.event.pull_request.head.ref }}
                   repository: ${{ github.event.pull_request.head.repo.full_name }}
-                  fetch-depth: ${{ env.PR_COMMIT_COUNT }}
-                  show-progress: ${{ runner.debug == '1' && 'true' || 'false' }}
-            - name: 'Fetch relevant history from origin'
-              run: git fetch origin ${{ github.event.pull_request.base.ref }}
-            - name: Check CHANGELOG status
-              if: ${{ !contains(github.event.pull_request.labels.*.name, 'No Core Sync Required') && !contains(github.event.pull_request.labels.*.name, 'Backport from WordPress Core') }}
+            - name: Check the changelog folder
               env:
                   PR_NUMBER: ${{ github.event.number }}
               run: |

.github/workflows/sync-backport-changelog.yml

@@ -0,0 +1,76 @@
+name: Sync Core Backport Issue
+
+on:
+    push:
+        branches:
+            - trunk
+
+jobs:
+    sync-backport-changelog:
+        name: Sync Core Backport Issue
+        runs-on: ubuntu-latest
+        steps:
+            - uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
+              with:
+                  fetch-depth: 2 # Fetch the last two commits to compare changes
+            - name: Check for changes in backport-changelog
+              run: |
+                  git diff --quiet HEAD^ HEAD -- backport-changelog || echo "changes=true" >> $GITHUB_OUTPUT
+            - name: Sync Issue
+              if: env.changes == 'true'
+              uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7.0.1
+              with:
+                  script: |
+                      const labelName = '🤖 Sync Backport Changelog';
+                      const issues = await github.paginate(github.rest.issues.listForRepo, {
+                        owner: context.repo.owner,
+                        repo: context.repo.repo,
+                        labels: [labelName],
+                        state: 'open',
+                        per_page: 1,
+                      });
+
+                      if (issues.length === 0) {
+                        console.log(`No issues found with the "${labelName}" label.`);
+                        return;
+                      }
+
+                      const [latestIssue] = issues;
+                      const versionMatch = latestIssue.title.match(/(\d+\.\d+)/);
+                      if (!versionMatch) {
+                        console.log('Could not find a version number in the latest issue title.');
+                        return;
+                      }
+
+                      const version = versionMatch[1];
+                      console.log(`Latest version: ${version}`);
+
+                      const { execSync } = require('child_process');
+                      const processedChangelog = execSync(`awk '/./ {print ($0 ~ /^[-*]/ ? "  " : "- ") $0}' backport-changelog/${version}/*.md`).toString().trim();
+
+                      const startDelimiter = '<!-- START TRUNK BACKPORT CHANGELOG -->';
+                      const endDelimiter = '<!-- END TRUNK BACKPORT CHANGELOG -->';
+                      const autoGeneratedContent = `${startDelimiter}\n${processedChangelog}\n${endDelimiter}`;
+
+                      const regex = new RegExp(`${startDelimiter}[\\s\\S]*${endDelimiter}`);
+                      let newBody;
+
+                      if (regex.test(latestIssue.body)) {
+                        // If delimiters exist, replace the content between them
+                        newBody = latestIssue.body.replace(regex, autoGeneratedContent);
+                      } else {
+                        // If delimiters don't exist, append the new content at the end
+                        newBody = `${latestIssue.body}\n\n${autoGeneratedContent}`;
+                      }
+
+                      if (newBody.trim() !== latestIssue.body.trim()) {
+                        await github.rest.issues.update({
+                          owner: context.repo.owner,
+                          repo: context.repo.repo,
+                          issue_number: latestIssue.number,
+                          body: newBody
+                        });
+                        console.log('Issue description updated successfully.');
+                      } else {
+                        console.log('Issue description is already up to date.');
+                      }