auth-yes/tasks/audits/2026-0827-audit-2-phase-4.md

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.