Delete stale PR link-checker comment when links are clean (#61993)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

Author: 3 people

src/links/scripts/check-links-pr.ts

@@ -177,21 +177,35 @@ async function commentOnPR(brokenLinks: BrokenLink[], actionUrl?: string) {
   const octokit = github()
   const comment = generatePRComment(brokenLinks, { actionUrl })
 
-  if (!comment) {
-    console.log('No broken links to report')
-    return
-  }
-
-  // Find existing comment
+  // Find any existing comment we previously posted (identified by the hidden marker)
+  const marker = '<!-- link-checker-pr-comment -->'
   const { data: comments } = await octokit.rest.issues.listComments({
     owner,
     repo,
     issue_number: pullNumber,
   })
-
-  const marker = '<!-- link-checker-pr-comment -->'
   const existingComment = comments.find((c) => c.body?.includes(marker))
 
+  if (!comment) {
+    console.log('No broken links to report')
+    // Links are now clean: remove any stale comment from an earlier commit.
+    // Best-effort: a concurrent run may have already deleted it (404), and
+    // cleanup should never turn an otherwise-passing run into a failure.
+    if (existingComment) {
+      try {
+        await octokit.rest.issues.deleteComment({
+          owner,
+          repo,
+          comment_id: existingComment.id,
+        })
+        console.log(`Deleted stale PR comment: ${existingComment.id}`)
+      } catch (err) {
+        console.warn(`Could not delete stale PR comment ${existingComment.id}:`, err)
+      }
+    }
+    return
+  }
+
   if (existingComment) {
     await octokit.rest.issues.updateComment({
       owner,
@@ -287,6 +301,14 @@ async function main() {
 
   if (allBrokenLinks.length === 0 && allRedirectLinks.length === 0) {
     console.log(chalk.green('✅ All links valid!'))
+    // Remove any stale comment posted on an earlier commit, now that links are clean
+    if (process.env.SHOULD_COMMENT === 'true') {
+      try {
+        await commentOnPR([], process.env.ACTION_RUN_URL)
+      } catch (err) {
+        console.warn('Could not clean up stale PR comment:', err)
+      }
+    }
     process.exit(0)
   }