Cache Tag Invalidation Certainty

1// A cacheTag() in the cached function is not proof that CMS edits invalidate it.
2// The report must not claim "existing tags preserve instant updates" unless the
3// investigation verifies matching revalidateTag/updateTag paths.
4
5export const metadata = {
6  id: 'cache-tag-invalidation-certainty',
7  description: 'Remove unsupported certainty that existing cache tags already preserve CMS/on-demand invalidation.',
8};
9
10const STRING_FIELDS = ['what', 'why', 'fix', 'currentBehavior', 'desiredBehavior', 'verify'];
11const UNSUPPORTED_TAG_CERTAINTY =
12  /\b(?:existing|current)\s+(?:cache\s+)?tags?\b[^.!?\n]{0,160}\b(?:preserve|keep|cover|maintain|ensure)\b[^.!?\n]{0,160}\b(?:instant|on-demand|CMS|content|publish|update
13const SAFE_REPLACEMENT =
14  'Confirm a matching revalidateTag() or updateTag() path for each cacheTag() before increasing the cache lifetime.';
15
16export function apply(rec) {
17  const text = STRING_FIELDS.map((field) => rec?.[field]).filter((s) => typeof s === 'string').join('\n');
18  if (!/\bcache(?:Life|Tag)\b/.test(text)) return {};
19  const tags = [];
20  for (const field of STRING_FIELDS) {
21    if (typeof rec?.[field] !== 'string') continue;
22    const before = rec[field];
23    const after = before.replace(UNSUPPORTED_TAG_CERTAINTY, SAFE_REPLACEMENT);
24    if (after !== before) {
25      rec[field] = after;
26      tags.push(`cache-tag-invalidation-certainty:${field}`);
27    }
28  }
29  return tags.length > 0 ? { tags, needsReview: true } : {};
30}