---
phase: 03
slug: spec-10-smoke-verification-dom-event-log-verification
plan: 04
type: execute
wave: 4
depends_on:
  - 01
  - 02
  - 03
files_modified:
  - tests/uat/lib/harness-page-driver.ts
  - tests/uat/harness.test.ts
autonomous: true
requirements: []
tags:
  - uat-harness
  - a32
  - ram-ceiling
  - spec-10-9-best-effort
  - approach-b
  - page-metrics
  - charter-d-p3-04
user_setup: []
must_haves:
  truths:
    - "puppeteer.Page.metrics() returns a JSHeapUsedSize value (>= 0) for the harness page realm"
    - "JSHeapUsedSize for the harness page realm is below 50 MB (page-realm only; SW context excluded per RESEARCH Pitfall 2)"
    - "Driver emits an explicit diagnostic line: 'NOTE: page-realm only; SW context excluded' (prevents operator misinterpretation)"
    - "UAT harness exits 0 with 32 + 1 = 33/33 assertions GREEN (A31 baseline preserved + new A32)"
  artifacts:
    - path: "tests/uat/lib/harness-page-driver.ts"
      provides: "driveA32 host-side Page.metrics scaffolding (best-effort; explicit page-realm-only diagnostic)"
      contains: "driveA32"
    - path: "tests/uat/harness.test.ts"
      provides: "driveA32 import + drivers-array push entry (no wrapped driver — Page.metrics needs only page, not downloadsDir)"
      contains: "driveA32"
  key_links:
    - from: "tests/uat/harness.test.ts"
      to: "tests/uat/lib/harness-page-driver.ts driveA32"
      via: "import + drivers-array push"
      pattern: "driveA32"
    - from: "tests/uat/lib/harness-page-driver.ts driveA32"
      to: "puppeteer.Page.metrics() CDP Performance.getMetrics"
      via: "await page.metrics()"
      pattern: "page.metrics\\(\\)"
---

<objective>
Extend the UAT harness with A32 — best-effort scaffolding for SPEC §10 #9
(extension background RAM ≤ 50 MB). Per D-P3-04 locked decision: this is
best-effort + operator-driven. The harness DOES NOT measure the MV3
service worker heap (RESEARCH Pitfall 2: Page.metrics is page-realm
only). The genuine binding §10 #9 gate is the operator's
`chrome://memory-internals` observation, recorded in Plan 03-05
VERIFICATION.md `human_verification` block.

A32 SHIPS the optional Page.metrics scaffolding per RESEARCH Open
Question 3 recommendation (~30 lines; cost-cheap; informational value).
Diagnostic output explicitly states the page-realm scope so the
operator never confuses an automation GREEN with full §10 #9 closure.

Purpose: Provides a low-cost informational floor for page-realm heap
usage and exercises the puppeteer.Page.metrics API end-to-end so Phase
4 (programmatic RAM measurement upgrade) inherits a working scaffold.

Output: A32 assertion with 2 host-side checks (Page.metrics returned
JSHeapUsedSize >= 0 + JSHeapUsedSize < 50 MB) + an explicit diagnostic
line about page-realm scope; UAT count 32 → 33 GREEN.
</objective>

<execution_context>
@$HOME/.claude/get-shit-done/workflows/execute-plan.md
@$HOME/.claude/get-shit-done/templates/summary.md
</execution_context>

<context>
@.planning/PROJECT.md
@.planning/ROADMAP.md
@.planning/STATE.md
@.planning/REQUIREMENTS.md
@.planning/phases/03-spec-10-smoke-verification-dom-event-log-verification/03-CONTEXT.md
@.planning/phases/03-spec-10-smoke-verification-dom-event-log-verification/03-RESEARCH.md
@.planning/phases/03-spec-10-smoke-verification-dom-event-log-verification/03-PATTERNS.md
@.planning/phases/03-spec-10-smoke-verification-dom-event-log-verification/03-01-PLAN.md
@.planning/phases/03-spec-10-smoke-verification-dom-event-log-verification/03-02-PLAN.md
@.planning/phases/03-spec-10-smoke-verification-dom-event-log-verification/03-03-PLAN.md

<interfaces>
<!-- Key contracts the executor needs. -->

From puppeteer ^25.0.2 (Page.metrics):

  interface Metrics {
    Timestamp?: number;
    Documents?: number;
    Frames?: number;
    JSEventListeners?: number;
    Nodes?: number;
    LayoutCount?: number;
    RecalcStyleCount?: number;
    LayoutDuration?: number;
    RecalcStyleDuration?: number;
    ScriptDuration?: number;
    TaskDuration?: number;
    JSHeapUsedSize?: number;   // <- bytes; the field A32 reads
    JSHeapTotalSize?: number;
  }
  page.metrics(): Promise<Metrics>;

From RESEARCH.md §"Code Example A3X":

  - Page.metrics is page-realm only — JSHeapUsedSize covers V8 isolate
    of THIS Page, NOT the MV3 service worker (separate target).
  - 50 MB threshold per SPEC §10 #9; treat as best-effort floor for the
    page realm alone.
  - Diagnostic copy gate: emit
    'NOTE: page-realm only; SW context measurement requires
    chrome://memory-internals operator verification per D-P3-04.'

From src/shared/types.ts: no UserEvent / type changes for A32.
</interfaces>

# Plan Anchors

- **Sequential wave assignment (per RESEARCH Pitfall 6 + file-overlap rule):** Plan 03-04 lives in wave 4
  modifies tests/uat/lib/harness-page-driver.ts + tests/uat/harness.test.ts
  (SAME files as Plans 03-01..03; depends_on enforces sequential).
- **NO page-side assertion needed.** Page.metrics is a host-side
  puppeteer API. Unlike A24..A31, A32 does NOT call assertA32 inside
  page.evaluate — there's no need for a window.__mokoshHarness method.
  This is consistent with how the host-side latency portion of A25 is
  computed; A32 is similar but skips the page-side entirely.
- **No setupFreshRecording, no SAVE, no zip read.** A32 measures the
  current heap state of the harness page; no archive is produced.
- **RESEARCH Pitfall 2 mitigation (HARD):** the diagnostic line about
  page-realm scope MUST be emitted regardless of pass/fail. This
  prevents an operator from glancing at "A32 GREEN" and concluding §10
  #9 is closed.
- **50 MB threshold:** SPEC §10 #9 + CON-ram-ceiling. Page-realm typical
  values: a few MB (Plan 02-04 harness measurements show ~2-8 MB
  page-realm heap during recording). Far below the 50 MB ceiling on
  any reasonable run.
- **FORBIDDEN_HOOK_STRINGS lockstep:** A32 is host-side only; Page.metrics
  is not bundled to the page. Tier-1 inventory stays at 12 entries.
- **A6 in RESEARCH Assumptions Log MEDIUM-risk noted:** "if Plan 03-04
  scaffolding requires a new bridge op (e.g., `get-page-metrics` from
  offscreen → harness), that would add 1-2 entries." This plan AVOIDS
  that: Page.metrics is read from the host puppeteer object directly;
  no new bridge ops added; no new __MOKOSH_UAT__ symbols.
</context>

<tasks>

<task type="auto" tdd="false">
  <name>Task 1: Add driveA32 host-side (puppeteer.Page.metrics scaffolding) + orchestrator wiring</name>
  <files>tests/uat/lib/harness-page-driver.ts, tests/uat/harness.test.ts</files>
  <read_first>
    - tests/uat/lib/harness-page-driver.ts (full sense of the file; in particular how driveA1 is a 1-line page.evaluate wrapper, contrasting with A32 which is pure host-side)
    - tests/uat/harness.test.ts where Plan 03-03 added driveA31 + driveA31Wrapped + drivers-array entry (study shape)
    - .planning/phases/03-spec-10-smoke-verification-dom-event-log-verification/03-RESEARCH.md §"Code Example A3X" (canonical scaffolding shape; verbatim copy)
    - .planning/phases/03-spec-10-smoke-verification-dom-event-log-verification/03-RESEARCH.md §"Pitfall 2" (diagnostic-copy gate)
  </read_first>
  <behavior>
    Host-side (`tests/uat/lib/harness-page-driver.ts`):
    - Adds `export async function driveA32(page: Page): Promise<AssertionRecord>`:
      - Calls `const metrics = await page.metrics();`
      - Computes `const jsHeapBytes = metrics.JSHeapUsedSize ?? -1;`
      - Computes `const jsHeapMB = jsHeapBytes >= 0 ? jsHeapBytes / (1024 * 1024) : -1;`
      - Pushes A32.1 (Page.metrics returned JSHeapUsedSize): expected '>= 0', actual `jsHeapBytes`, passed `jsHeapBytes >= 0`
      - Pushes A32.2 (page-realm JS heap < 50 MB): expected '< 50 MB', actual `${jsHeapMB.toFixed(2)} MB`, passed `jsHeapMB >= 0 && jsHeapMB < 50`
      - Pushes the mandatory diagnostic: `'NOTE: page-realm only; SW context measurement requires chrome://memory-internals operator verification per D-P3-04.'`
      - Also pushes informational diagnostics: `JSHeapUsedSize=${jsHeapBytes} bytes` and `JSHeapTotalSize=${metrics.JSHeapTotalSize ?? -1} bytes`
      - Returns AssertionRecord computed `passed = checks.every(c => c.passed)`
    - The new constant `A32_RAM_CEILING_BYTES = 50 * 1024 * 1024` makes the threshold readable.

    Orchestrator (`tests/uat/harness.test.ts`):
    - Adds `driveA32,` to import block (after `driveA31,`).
    - NO `driveA32Wrapped` const needed (driveA32 takes only `page`).
    - Adds `{ name: 'A32', drive: driveA32 },` to drivers array AFTER the A31 entry, with banner comment citing D-P3-04 + Pitfall 2.
    - Updates orchestrator banner line to append `, A32`.
  </behavior>
  <action>
1. Open `tests/uat/lib/harness-page-driver.ts`. At the end of the file (AFTER driveA31 added by Plan 03-03), append:

```typescript

/* ─── Plan 03-04 — driveA32 (RAM scaffolding best-effort) ──────────── */

/** RAM ceiling per SPEC §10 #9 + CON-ram-ceiling. */
const A32_RAM_CEILING_BYTES = 50 * 1024 * 1024;
/** Bytes-per-MB factor for diagnostic copy. */
const A32_BYTES_PER_MB = 1024 * 1024;

/**
 * Drive A32 (Plan 03-04 — SPEC §10 #9 RAM best-effort per D-P3-04).
 *
 * Reads puppeteer.Page.metrics() against the harness page and asserts
 * JSHeapUsedSize is below the 50 MB ceiling. This is informational
 * scaffolding ONLY:
 *
 *   - RESEARCH Pitfall 2: Page.metrics is page-realm only. The MV3
 *     service worker is a separate Puppeteer target with its own V8
 *     isolate; page.metrics() does not aggregate across workers/iframes.
 *   - The page-realm value reported here is NOT the operator-facing
 *     "extension background RAM" measurement that SPEC §10 #9 requires.
 *   - The binding §10 #9 gate lives in Plan 03-05 VERIFICATION.md
 *     `human_verification` block (operator runs chrome://memory-internals
 *     OR chrome://extensions service-worker memory display).
 *
 * Why ship this anyway (per RESEARCH Open Question 3):
 *   - Low cost (~30 lines; single API call; no new bundle surface).
 *   - Exercises the Page.metrics API end-to-end so Phase 4 (programmatic
 *     RAM measurement upgrade) inherits a working scaffold.
 *   - Provides a sanity floor — if the harness page-realm heap ever
 *     blows past 50 MB, something has gone catastrophically wrong in
 *     the test infrastructure itself (not necessarily a §10 #9 regression
 *     in production).
 *
 * The diagnostic line about page-realm scope MUST be emitted regardless
 * of pass/fail per Pitfall 2.
 *
 * @param page - The harness page from `launchHarnessBrowser`.
 * @returns AssertionRecord with 2 checks (heap returned + heap < 50 MB)
 *          + explicit page-realm-only diagnostic.
 */
export async function driveA32(page: Page): Promise<AssertionRecord> {
  const checks: CheckRecord[] = [];
  const diagnostics: string[] = [];

  // Pitfall 2 gate: emit the page-realm caveat BEFORE any other diagnostic
  // so it leads in the structured output (the operator sees it first).
  diagnostics.push(
    'NOTE: page-realm only; SW context measurement requires chrome://memory-internals operator verification per D-P3-04.',
  );

  let metricsErr: string | null = null;
  let jsHeapBytes = -1;
  let jsHeapTotal = -1;
  try {
    const metrics = await page.metrics();
    jsHeapBytes = metrics.JSHeapUsedSize ?? -1;
    jsHeapTotal = metrics.JSHeapTotalSize ?? -1;
  } catch (err) {
    metricsErr = err instanceof Error ? err.message : String(err);
  }

  const jsHeapMB = jsHeapBytes >= 0 ? jsHeapBytes / A32_BYTES_PER_MB : -1;
  diagnostics.push(`A32 JSHeapUsedSize=${jsHeapBytes} bytes (${jsHeapMB.toFixed(2)} MB)`);
  diagnostics.push(`A32 JSHeapTotalSize=${jsHeapTotal} bytes`);
  if (metricsErr !== null) {
    diagnostics.push(`A32 Page.metrics threw: ${metricsErr}`);
  }

  checks.push({
    name: 'A32.1: Page.metrics returned a JSHeapUsedSize value >= 0',
    expected: '>= 0',
    actual: jsHeapBytes,
    passed: jsHeapBytes >= 0,
  });
  checks.push({
    name: `A32.2: Page-realm JS heap < ${A32_RAM_CEILING_BYTES / A32_BYTES_PER_MB} MB (NOTE: scaffolding only; SW context excluded per D-P3-04)`,
    expected: `< ${A32_RAM_CEILING_BYTES / A32_BYTES_PER_MB} MB`,
    actual: jsHeapMB >= 0 ? `${jsHeapMB.toFixed(2)} MB` : 'unavailable',
    passed: jsHeapBytes >= 0 && jsHeapBytes < A32_RAM_CEILING_BYTES,
  });

  const passed = checks.every((c) => c.passed);
  return {
    passed,
    name: 'A32 — RAM scaffolding (best-effort; page-realm only per D-P3-04 / SPEC §10 #9)',
    checks,
    diagnostics,
    error: metricsErr ?? undefined,
  };
}
```

2. Open `tests/uat/harness.test.ts`. In the import block from `./lib/harness-page-driver`, AFTER `driveA31,` and BEFORE `getManifestVersion,` add:

```typescript
  // Plan 03-04 — RAM scaffolding best-effort (SPEC §10 #9 per D-P3-04)
  driveA32,
```

3. In the drivers array, AFTER the `{ name: 'A31', ... }` entry from Plan 03-03, add:

```typescript
    // Plan 03-04 A32: RAM scaffolding (SPEC §10 #9 best-effort per D-P3-04).
    // NOTE — Page.metrics is page-realm only; SW context is a separate
    // Puppeteer target (RESEARCH Pitfall 2). A32 is informational
    // scaffolding; the binding §10 #9 gate lives in Plan 03-05
    // VERIFICATION.md `human_verification` block. No wrapped const
    // needed — driveA32 takes only `page`.
    { name: 'A32', drive: driveA32 },
```

4. Update the orchestrator banner line (line 268) to append `, A32`:

```typescript
  process.stdout.write('Architecture: A0 pre-flight + extension-internal page driver (A1..A14, A15..A17, A18..A22, A23, A24, A25, A26, A27, A28, A29, A30, A31, A32)\n');
```

5. Run `npx tsc --noEmit`. Expected: clean.
6. Run `HEADLESS=1 SKIP_PROD_REBUILD=0 npm run test:uat`. Expected: `33/33 GREEN`.
  </action>
  <verify>
    <automated>npx tsc --noEmit; D=$(grep -c "driveA32" tests/uat/lib/harness-page-driver.ts); test "$D" -ge 2 &amp;&amp; H=$(grep -c "driveA32" tests/uat/harness.test.ts); test "$H" -ge 2 &amp;&amp; grep -q "NOTE: page-realm only" tests/uat/lib/harness-page-driver.ts &amp;&amp; HEADLESS=1 SKIP_PROD_REBUILD=0 npm run test:uat</automated>
  </verify>
  <acceptance_criteria>
    - `npx tsc --noEmit` exits 0.
    - `grep -c 'driveA32' tests/uat/lib/harness-page-driver.ts` returns >=2.
    - `grep -c 'driveA32' tests/uat/harness.test.ts` returns >=2 (import line + drivers-array push; no wrapped const).
    - `grep -c 'NOTE: page-realm only' tests/uat/lib/harness-page-driver.ts` returns exactly 1.
    - `grep -c 'page.metrics()' tests/uat/lib/harness-page-driver.ts` returns exactly 1.
    - `grep -c 'A32_RAM_CEILING_BYTES' tests/uat/lib/harness-page-driver.ts` returns >=2 (declaration + usage).
    - `HEADLESS=1 SKIP_PROD_REBUILD=0 npm run test:uat` exits 0 with stdout containing `UAT harness: 33/33 assertions passed` AND the diagnostic line `NOTE: page-realm only; SW context measurement requires chrome://memory-internals operator verification per D-P3-04.` (printed by printAssertionResult on A32).
    - `npm test -- --run tests/background/no-test-hooks-in-prod-bundle.test.ts` exits 0 (Tier-1 inventory stays at 12).
  </acceptance_criteria>
  <done>
    UAT harness runs 33/33 GREEN. A32 emits the page-realm-only diagnostic
    on EVERY run (pass or fail). FORBIDDEN_HOOK_STRINGS unchanged at 12.
    Page.metrics scaffolding lives in the harness for Phase 4 to upgrade.
    The binding §10 #9 gate remains operator-driven and is recorded as
    human_verification in Plan 03-05.
  </done>
</task>

</tasks>

<threat_model>
## Trust Boundaries

| Boundary | Description |
|----------|-------------|
| Puppeteer host ↔ CDP | Page.metrics is a thin wrapper over CDP Performance.getMetrics; runs in the puppeteer host process, no extension code path |
| Page realm ↔ host realm | A32 does NOT use page.evaluate; no new contract between page and host |
| dist-test/ ↔ dist/ | Two-bundle separation: Plan 03-04 adds NO test-only symbols; production bundle invariant unchanged |

## STRIDE Threat Register

| Threat ID | Category | Component | Disposition | Mitigation Plan |
|-----------|----------|-----------|-------------|-----------------|
| T-03-04-01 | Repudiation | Operator interprets A32 GREEN as full §10 #9 closure, skips chrome://memory-internals check | mitigate | Mandatory diagnostic line `'NOTE: page-realm only; SW context measurement requires chrome://memory-internals operator verification per D-P3-04.'` emitted on EVERY run; check name itself includes the caveat; Plan 03-05 VERIFICATION.md explicitly lists §10 #9 in `human_verification` block. Three layers of operator-visible signal. |
| T-03-04-02 | Information Disclosure | Test-only hook surface leaking to production bundle | mitigate | A32 is host-side only; Page.metrics is not bundled to the page realm. FORBIDDEN_HOOK_STRINGS unchanged at 12 entries. |
| T-03-04-03 | Denial of Service | Page.metrics returns 0 or throws on first call after browser launch | mitigate | A32 wraps the call in try/catch + falls through gracefully (jsHeapBytes stays -1; A32.1 RED with clear diagnostic). Per A3 in RESEARCH Assumptions Log, Page.metrics has been stable since Puppeteer 1.x; failure is extremely unlikely on 25.0.2. |
| T-03-04-04 | Elevation of Privilege | New chrome.* permission grant for measurement | accept | A32 uses zero chrome.* APIs. Page.metrics is a CDP call, not an extension API. No manifest delta. |

No new production surface; threat surface unchanged from Plan 03-03.
UAT harness extension is test-only and adds no bundle surface (Page.metrics
is host-side only).
</threat_model>

<verification>
- `npx tsc --noEmit` exits 0.
- `HEADLESS=1 SKIP_PROD_REBUILD=0 npm run test:uat` exits 0 with 33/33 GREEN.
- The diagnostic line `NOTE: page-realm only; SW context measurement requires chrome://memory-internals operator verification per D-P3-04.` appears in stdout from A32.
- `npm test -- --run tests/background/no-test-hooks-in-prod-bundle.test.ts` exits 0 (12 FORBIDDEN_HOOK_STRINGS × 0 hits each).
</verification>

<success_criteria>
- A32 GREEN with 2 checks (heap returned + heap < 50 MB).
- Pitfall 2 diagnostic emitted on every run.
- Page.metrics scaffolding in place for Phase 4 to upgrade.
- FORBIDDEN_HOOK_STRINGS unchanged at 12 entries.
- vitest baseline preserved (171/171 GREEN).
- Plan 03-05 will record §10 #9 as `human_verification` regardless of A32
  status — A32 is informational scaffolding, NOT the binding gate.
</success_criteria>

<output>
After completion, create
`.planning/phases/03-spec-10-smoke-verification-dom-event-log-verification/03-04-SUMMARY.md`
documenting:
- A32 host-side-only scaffolding rationale (no page-side; Page.metrics is host)
- D-P3-04 + Pitfall 2 compliance (mandatory page-realm-only diagnostic)
- Phase 4 inheritance: programmatic RAM measurement upgrade path
- UAT 32 → 33 GREEN; Tier-1 inventory unchanged at 12
- Plan 03-05 wave dependency: VERIFICATION.md aggregator; depends on Plans 03-01..04 GREEN
</output>
