# Post-Implementation Audit: Phase 4 (Persistent Architectural Test Suite)

## 1. Test Suite & Verification

- **`deno fmt`**: Passed (All 6 architectural test suites formatted).
- **`deno task lint`**: Passed (`deno lint` and `scripts/lint_arch.ts` passed
  with 0 errors; all files $\le 72$ lines, zero banned DOM API violations).
- **`deno task check`**: Passed across all workspace modules (`server/`, `sdk/`,
  `ui/`, `infra/`, `src/`).
- **`deno test -A --no-check`**: Passed (90 tests across 30 steps with 0
  failures).

## 2. Scope Implemented & Verified

1. **Transport Efficiency & Latency
   (`src/tests/arch/transport_efficiency.test.ts`):**
   - Asserts non-streaming point-to-point actions (`/join`, `/login`) execute
     rapidly without SSE overhead.
   - Asserts the 16KB payload ceiling guard rejects oversized bodies with
     413/400.
2. **SSE Stream Lifecycle & Leak Teardown
   (`src/tests/arch/sse_lifecycle.test.ts`):**
   - Asserts `streamDatastar` handles client `AbortSignal` disconnects
     gracefully and executes clean teardown logic.
3. **Proxy Buffering Invariant (`src/tests/arch/proxy_buffering.test.ts`):**
   - Validates that streaming endpoints emit `X-Accel-Buffering: no` and
     `Cache-Control: no-cache` headers to bypass reverse-proxy buffering.
4. **Error Fragment Morph Invariant (`src/tests/arch/error_fragment.test.ts`):**
   - Validates that validation and route errors return HTML fragments targeting
     `#status-banner` or `.field-error`.
5. **XSS & Escape Fuzzing Harness (`src/tests/arch/xss_fuzzing.test.tsx`):**
   - Fuzzes event names, user labels, and usernames with `<script>`, `onerror=`,
     and attribute breakout payloads to ensure Hono SSR JSX strictly escapes all
     dynamic entities into safe HTML entities.
6. **Dual-Mode Content Negotiation
   (`src/tests/arch/content_negotiation.test.ts`):**
   - Tests `determineClientType()` across `datastar`, `browser`, `shell` (curl),
     and `cli` (JSON) request profiles.
7. **Core Decoupling & Self-Containment:**
   - 100% of all imports in `src/` are internal to `src/core/` and
     `src/shared/ui/`.
   - Zero legacy `server/` imports remain.

## 3. Decision

**Decision: APPROVED & GREEN.** 🟢 Phase 4 is complete, robust, and verified.