suaveplan/openspec/archive/2026-05-26-api-sse-bun/tasks.md

Tasks — @suaveplan/api-sse-bun

Every checkbox MUST reflect work actually done in this change.

0. Pre-flight (non-negotiable)

• 0.1 Confirm clean working tree (git status reports nothing) and no in-flight worktrees with uncommitted work (git worktree list then git status in each)
• 0.2 If any worktrees exist under .claude/worktrees/, account for each one: still-active agent, work-pending-merge, or stale-and-prune. Stale worktrees MUST be removed (git worktree remove) before opening a new one — code that has been lost twice on main is the failure mode this guards against.
• 0.3 Confirm the package set in MANIFEST.md matches find packages -maxdepth 3 -name package.json count. Drift here means a prior change archived without regenerating the manifest.

1. Spec authoring

• 1.1 Read design doc §11.5, §11.6, §11.7
• 1.2 Read umbrella Stage 7 acceptance
• 1.3 Read sibling openspec/changes/api-ws-bun/ and openspec/changes/api-ws-broker-redis/ for broker integration
• 1.4 Read openspec/AGENTS.md Sections 13 and 14
• 1.5 Draft proposal.md
• 1.6 Draft specs/api-sse-bun/spec.md
• 1.7 Every requirement carries a **Verified by:** line

2. Implementation

• 2.1 Scaffold packages/api-stack/api/api-sse-bun/
• 2.2 src/options/options.ts — BunSseEngineOptions Zod schema
• 2.3 src/engine/bun-sse-engine.ts — createBunSseEngine(opts)
• 2.4 src/stream/sse-stream.ts — SSE framing (id:, event:, data:, retry:, :keepalive comments)
• 2.5 src/handshake/handshake.ts — pipeline steps 1–7 wiring; principal freeze
• 2.6 src/last-event-id/last-event-id.ts — parse Last-Event-Id header; consult event buffer
• 2.7 src/event-buffer/event-buffer.ts — in-memory ring buffer; delegate to broker when wired
• 2.8 src/keep-alive/keep-alive.ts — keepAliveCommentMs scheduler
• 2.9 src/limits/tenant-cap.ts — maxConnectionsPerTenant enforcement
• 2.10 src/compression/compression.ts — gzip stream when client accepts; emit Content-Encoding: gzip
• 2.11 src/subscription/subscription-bus.ts — registers against the shared subscription bus
• 2.12 src/instruments/instruments.ts — sse.* OTel instruments per §11.7 + this package's extensions
• 2.13 src/error-codes/error-codes.ts — 10 SSE_BUN_* codes
• 2.14 ./testing subpath — re-export runSseEngineConformance bound to factory
• 2.15 src/index.ts — explicit named re-exports

3. Tests

• 3.1 Unit tests, every it(...) { timeout: 5000 }
• 3.2 Conformance test runs runSseEngineConformance
• 3.3 Keep-alive test uses injectable schedule (FakeClock-style) and asserts cadence
• 3.4 Last-Event-Id replay test pins replay-before-live ordering
• 3.5 End-to-end test against real Bun.serve ({ timeout: 30000 }) — gracefully skips under non-Bun runtimes (vitest+node) since Bun.serve is the only transport; the in-process handshake suite drives the same ReadableStream path.
• 3.6 Multi-host fan-out test against real Redis broker — deferred to api-ws-broker-redis keystone (the broker package is the natural owner of the integration); the engine's broker-backed event buffer is unit-tested with a real SseBroker implementation in this package.
• 3.7 All tests import from @suaveplan/testing/runner

4. Documentation

• 4.1 Sibling .md per implementation file (13/13 = 100%)
• 4.2 README.md with ## Modules; document defaults table and explain SSE's "no client→server channel, no acks" boundary vs WS

5. Pre-archive verification

• 5.1 bun run check — 0/0/0
• 5.2 bunx turbo lint typecheck test --filter=@suaveplan/api-sse-bun — green
• 5.3 bunx turbo test:coverage --filter=@suaveplan/api-sse-bun — 100/100/100/100 (306 stmts, 102 branches, 73 funcs, 304 lines)
• 5.4 bun scripts/openspec-conformance.ts packages/api-stack/api/api-sse-bun — exit 0
• 5.5 bunx turbo build --filter=@suaveplan/api-sse-bun — green

6. Pre-archive 7-row checklist

• 6.1 Generics on engine surface (BunSseEngine.activeConnections is ReadonlyMap<string, ActiveConnection>); literal-type claims pinned via as const on SSE_BUN_CODES.
• 6.2 Zod schemas on options (resolveOptions strict-parses every primitive knob); subscription payloads carry the typed SseEvent schema from @suaveplan/api-sse.
• 6.3 Every SSE_BUN_* code thrown by a production path (HANDSHAKE_REJECTED, TENANT_CAP_EXCEEDED, BUFFER_MISS, EVENT_TOO_LARGE, LAST_EVENT_ID_INVALID, COMPRESSION_FAILED, STREAM_INTERRUPTED, PRINCIPAL_EXPIRED, BROKER_UNAVAILABLE, INVALID_TOPIC) — the registry-name-vs-throw audit is part of the conformance run.
• 6.4 Strict-mode tested (compression on vs off; broker wired vs in-memory event buffer)
• 6.5 OTel instruments asserted against fake MeterProvider (src/instruments/instruments.test.ts)
• 6.6 Lifecycle dedup: reconnect with same Last-Event-Id does not re-deliver already-delivered events — partially verified (replay test pins replay-before-live ordering); explicit "no double-delivery on reconnect" race is deferred to a later integration suite that owns the multi-host fan-out path.
• 6.7 No retroactive tick

7. Archive

• 7.1 Fold spec delta into openspec/specs/api-sse-bun/spec.md
• 7.2 Move to openspec/archive/<yyyy-mm-dd>-api-sse-bun/
• 7.3 Tick Stage-7 row in umbrella tasks
• 7.4 Refresh MANIFEST.md