test(BASE-04): freeze published DOM input and demo baselines

refactor/scripts/dom.test.mjs

@@ -0,0 +1,37 @@
+import assert from 'node:assert/strict'
+import test from 'node:test'
+import { domProfile, validateDomReport, verifyFrozenDom } from './dom.mjs'
+
+test('DOM baseline rejects absent interaction, fake input and wrong media', () => {
+  const frozen = verifyFrozenDom().report
+  for (const mutate of [
+    report => report.checks.pop(),
+    report => report.interactions.find(item => item.code === 'ArrowRight').trusted = false,
+    report => report.interactions.find(item => item.code === 'ArrowRight').afterTime = 0,
+    report => report.interactions.find(item => item.code === 'ArrowRight' && item.target === 'INPUT').afterHotkeys++,
+    report => report.capture.media['video.mp4'] = 'wrong',
+    report => report.unhandled.push('unexpected'),
+  ]) {
+    const changed = structuredClone(frozen)
+    mutate(changed)
+    assert.throws(() => validateDomReport(changed))
+  }
+})
+
+test('DOM comparison detects class, variable and layout changes without freezing subpixel widths', () => {
+  const frozen = verifyFrozenDom().report
+  const expected = domProfile(frozen)
+  const jitter = structuredClone(frozen)
+  jitter.observations.wide.controls[0].width += 0.01
+  assert.deepEqual(domProfile(jitter), expected)
+  for (const mutate of [
+    report => report.snapshot.tree.attributes.class = 'renamed',
+    report => report.snapshot.cssVariables.pop(),
+    report => report.snapshot.controlAttributes[0].role = 'button',
+    report => report.observations.narrow.controls[0].withinPlayer = false,
+  ]) {
+    const changed = structuredClone(frozen)
+    mutate(changed)
+    assert.notDeepEqual(domProfile(changed), expected)
+  }
+})