fix(ms-ai-architect): Enhet 4 — Last updated på datoløs advisor decision-trees.md (git content-commit 2026-06-23) [skip-docs]

tests/kb-update/test-backfill-last-updated.test.mjs

@@ -0,0 +1,98 @@
+// tests/kb-update/test-backfill-last-updated.test.mjs
+// TDD for the Last-updated backfill mechanism (Enhet 4, ⊥ R7). The applier
+// (backfill-last-updated.mjs) is a manifest-driven driver over the already-tested
+// insertMetaField primitive — the same shape as backfill-status.mjs. The ONLY new production
+// data is the frozen single-entry MANIFEST whose value is a git "content-commit" date.
+//
+// Scope: decision-trees.md is the corpus's ONE dateless file — the only skills/**/*.md whose
+// header lacks an English **Last updated:** (ground truth 2026-07-16). Its date is the authored
+// date of the last commit that changed the BODY (03d596e, 2026-06-23 — a Foundry namesweep),
+// EXCLUDING the R20/R21 metadata passes (a583599/5a0e8d7, which inserted only a header meta line
+// and changed no body). The "never today" rule is enforced against MEASURED_TODAY so a naive
+// last-commit date can never leak in.
+//
+// This suite pins:
+//   - MANIFEST self-consistency: one distinct entry, the known dateless path, a YYYY-MM-DD value
+//     that is not MEASURED_TODAY.
+//   - insertMetaField placement/idempotency on an advisor-shaped header fixture.
+//   - Corpus-state guard (the gap-discipline lock): the committed decision-trees.md carries
+//     **Last updated:** 2026-06-23 in its 500-byte header window, with title + Category + Status
+//     and body intact.
+
+import { test } from 'node:test';
+import assert from 'node:assert/strict';
+import { readFileSync } from 'node:fs';
+import { join, dirname } from 'node:path';
+import { fileURLToPath } from 'node:url';
+import { MANIFEST, MEASURED_TODAY } from '../../scripts/kb-update/backfill-last-updated.mjs';
+import { insertMetaField } from '../../scripts/kb-update/lib/transform.mjs';
+
+const __dirname = dirname(fileURLToPath(import.meta.url));
+const PLUGIN_ROOT = join(__dirname, '..', '..');
+
+const RE_ISO_DATE = /^\d{4}-\d{2}-\d{2}$/;
+const DECISION_TREES = 'skills/ms-ai-advisor/references/architecture/decision-trees.md';
+
+test('MANIFEST: exactly one distinct entry, the known dateless advisor file', () => {
+  assert.equal(MANIFEST.length, 1);
+  const paths = new Set(MANIFEST.map((m) => m.path));
+  assert.equal(paths.size, 1, 'duplicate path in MANIFEST');
+  assert.equal(MANIFEST[0].path, DECISION_TREES);
+});
+
+test('MANIFEST: value is a YYYY-MM-DD date and NOT MEASURED_TODAY (never-today guard)', () => {
+  for (const { path, lastUpdated } of MANIFEST) {
+    assert.ok(RE_ISO_DATE.test(lastUpdated), `${path}: '${lastUpdated}' is not YYYY-MM-DD`);
+    assert.notEqual(lastUpdated, MEASURED_TODAY, `${path}: date must never equal 'today'`);
+  }
+});
+
+test('MANIFEST: the frozen date is the measured content-commit date 2026-06-23', () => {
+  assert.equal(MANIFEST[0].lastUpdated, '2026-06-23');
+});
+
+test('insertMetaField: Last updated lands after the meta run, one line, body byte-identical', () => {
+  const fixture = [
+    '# Decision Trees for Microsoft AI',
+    '**Category:** Solution Architecture & Advisory',
+    '**Status:** Established Practice',
+    '',
+    'Akkumulerte beslutningstrær.',
+    '',
+    '## 1. Section',
+    'body',
+  ].join('\n');
+  const out = insertMetaField(fixture, 'Last updated', '2026-06-23');
+  const o = fixture.split('\n');
+  const n = out.split('\n');
+  // Exactly one line added.
+  assert.equal(n.length, o.length + 1);
+  // It lands immediately after the last meta line (Status), before the blank line.
+  assert.equal(n[3], '**Last updated:** 2026-06-23');
+  assert.equal(n[1], '**Category:** Solution Architecture & Advisory');
+  assert.equal(n[2], '**Status:** Established Practice');
+  // Everything from the insertion point down is byte-identical to the original tail.
+  assert.equal(o.slice(3).join('\n'), n.slice(4).join('\n'));
+});
+
+test('insertMetaField: idempotent — a file already carrying Last updated is unchanged', () => {
+  const withField = [
+    '# Title',
+    '**Last updated:** 2026-06-23',
+    '**Status:** Established Practice',
+    '',
+    '## S',
+  ].join('\n');
+  assert.equal(insertMetaField(withField, 'Last updated', '2026-01-01'), withField);
+});
+
+test('corpus guard: committed decision-trees.md carries Last updated 2026-06-23 in header window', () => {
+  const content = readFileSync(join(PLUGIN_ROOT, DECISION_TREES), 'utf8');
+  const head = content.slice(0, 500);
+  assert.match(head, /\*\*Last updated:\*\* 2026-06-23/, 'missing frozen Last updated in header window');
+  // Title + the R20/R21 base fields survive, body intact (regression lock).
+  assert.match(head, /^# Decision Trees for Microsoft AI/);
+  assert.match(head, /\*\*Category:\*\*/);
+  assert.match(head, /\*\*Status:\*\*/);
+  assert.match(content, /## 1\. Plattformvalg/);
+});