feat: add relative timestamps to preview deploy comments

.github/scripts/post-preview-comment.cjs

@@ -1,34 +1,57 @@
+const MARKER = '<!-- cf-preview -->';
+const MAX_PREVIOUS_ENTRIES = 10;
+
+const rtf = new Intl.RelativeTimeFormat('en', { numeric: 'auto' });
+
+const formatRelativeTime = (nowMs, thenMs) => {
+  const seconds = Math.max(0, Math.floor((nowMs - thenMs) / 1000));
+  if (seconds < 60) return rtf.format(0, 'second');
+  if (seconds < 3600) return rtf.format(-Math.floor(seconds / 60), 'minute');
+  if (seconds < 86400) return rtf.format(-Math.floor(seconds / 3600), 'hour');
+  return rtf.format(-Math.floor(seconds / 86400), 'day');
+};
+
+const formatEntry = ({ url, sha, iso }, repo, nowMs) => {
+  const commitLink = `[\`${sha.slice(0, 7)}\`](https://github.com/${repo}/commit/${sha})`;
+  const relative = formatRelativeTime(nowMs, new Date(iso).getTime());
+  return `${url} (${commitLink}) · ${relative} <!-- sha:${sha} ts:${iso} -->`;
+};
+
+const entryPattern = /(https:\/\/\S+\.pages\.dev).*?<!-- sha:([a-f0-9]+) ts:(\S+?) -->/g;
+
 module.exports = async ({ github, context, deploymentUrl, sha }) => {
   const { data: comments } = await github.rest.issues.listComments({
     issue_number: context.issue.number,
     owner: context.repo.owner,
     repo: context.repo.repo,
+    per_page: 100,
   });
-  const marker = '<!-- cf-preview -->';
-  const existing = comments.find((c) => c.body.includes(marker));
+  const existing = comments.find((c) => c.body.includes(MARKER));
   const repo = `${context.repo.owner}/${context.repo.repo}`;
-  const shortSha = sha.slice(0, 7);
-  const commitLink = `[\`${shortSha}\`](https://github.com/${repo}/commit/${sha})`;
+  const nowMs = Date.now();
 
-  let previous = '';
+  const priorEntries = [];
   if (existing) {
-    const entryPattern = /- (https:\/\/\S+\.pages\.dev)\s+\(.*?\)/g;
-    const currentLine = existing.body
-      .split('\n')
-      .find((l) => l.includes('.pages.dev') && !l.startsWith('-'));
-    const previousEntries = [];
-    if (currentLine) previousEntries.push(currentLine.trim());
-    for (const match of existing.body.matchAll(entryPattern)) {
-      previousEntries.push(match[0].slice(2));
-    }
-    const deduplicated = [...new Set(previousEntries)].filter((e) => !e.startsWith(deploymentUrl));
-    if (deduplicated.length > 0) {
-      const list = deduplicated.map((e) => `- ${e}`).join('\n');
-      previous = `\n\n<details>\n<summary>Previous previews</summary>\n\n${list}\n</details>`;
+    for (const [, url, prevSha, iso] of existing.body.matchAll(entryPattern)) {
+      if (url !== deploymentUrl) priorEntries.push({ url, sha: prevSha, iso });
     }
   }
+  const kept = priorEntries.slice(0, MAX_PREVIOUS_ENTRIES);
+
+  const previousSection =
+    kept.length > 0
+      ? `\n\n<details>\n<summary>Previous previews</summary>\n\n${kept
+          .map((e) => `- ${formatEntry(e, repo, nowMs)}`)
+          .join('\n')}\n</details>`
+      : '';
+
+  const current = formatEntry(
+    { url: deploymentUrl, sha, iso: new Date(nowMs).toISOString() },
+    repo,
+    nowMs,
+  );
+  const body = `${MARKER}\n### Preview deployment\n\n${current}${previousSection}`;
 
-  const body = `${marker}\n### Preview deployment\n\n${deploymentUrl} (${commitLink})${previous}`;
   if (existing) {
     await github.rest.issues.updateComment({
       owner: context.repo.owner,