led2/.planning/phases/03-communication-protocol/03-03-SUMMARY.md

phase, plan, subsystem, tags, dependency_graph, tech_stack, key_files, decisions, metrics

phase	plan	subsystem	tags	dependency_graph	tech_stack	key_files	decisions	metrics
03-communication-protocol	03	protocol	udp simulator e2e-testing fastapi tdd	requires provides affects 03-01 03-02 UDP simulator with packet logging UDPSender in FastAPI lifespan end-to-end protocol tests lightsync/main.py lightsync/protocol/simulator.py tests/test_e2e_protocol.py	added patterns asyncio.DatagramProtocol for UDP simulation TDD RED-GREEN asyncio.run() in tests (no pytest-asyncio) dataclass for structured packet logs	created modified lightsync/protocol/simulator.py tests/test_e2e_protocol.py lightsync/main.py	asyncio.run() test pattern chosen over pytest-asyncio — not installed, plan explicitly provided this fallback SimulatorProtocol uses port=0 in tests — OS assigns free port, read back via get_extra_info('sockname')[1] UDPSender stopped before registry.save() in shutdown — orderly teardown, no sends after socket close	duration completed_date tasks_completed files_created files_modified 2 min 2026-04-06 2 2 1

Phase 03 Plan 03: UDP Simulator and FastAPI Integration Summary

One-liner: Async UDP simulator parses all 4 WLED packet types (DRGB/DRGBW/DNRGB/ANIM_CMD) with structured packet logging; UDPSender integrated into FastAPI lifespan; 7 end-to-end tests prove full animation-to-wire pipeline.

What Was Built

Task 1: UDP Simulator with Packet Logging (TDD)

lightsync/protocol/simulator.py — a SimulatorProtocol(asyncio.DatagramProtocol) that:

• Parses DRGB (0x02): extracts led_count = (len(data)-2) // 3
• Parses DRGBW (0x03): extracts led_count = (len(data)-2) // 4
• Parses DNRGB (0x04): extracts big-endian uint16 start index at bytes 2-3, led_count = (len(data)-4) // 3
• Parses ANIM_CMD (0xAC): calls decode_animation_cmd, stores result in PacketLog.decoded
• Stores all received packets as PacketLog dataclasses for test assertions

tests/test_e2e_protocol.py — 7 end-to-end tests using asyncio.run():

• test_e2e_drgb_10_pixels — DRGB 10 pixels, led_count verified
• test_e2e_drgbw_10_pixels — DRGBW 10 pixels, led_count verified
• test_e2e_dnrgb_600_pixels — 600-LED frame splits into 2 packets, start_indices 0 and 489
• test_e2e_animation_cmd_chase — animation command round-trip, decoded animation=="chase"
• test_e2e_full_pipeline — solid_color render -> encode_drgb -> send -> 20-LED DRGB frame verified
• test_e2e_sk6812_rgbw_pipeline — solid_color -> RGBW encode -> DRGBW 15-LED frame verified
• test_simulator_standalone_import — run_simulator importable without error

TDD flow: RED commit (failing import) -> GREEN commit (simulator implemented, all 7 pass).

Task 2: UDPSender into FastAPI Lifespan

lightsync/main.py updated:

• Added from lightsync.protocol.udp_sender import UDPSender import
• Lifespan startup: UDPSender() created, await udp_sender.start(), assigned to app.state.udp_sender
• Lifespan shutdown: await app.state.udp_sender.stop() before await registry.save()
• All existing lifespan code unchanged (beats cache, registry, show_store)

Deviations from Plan

None — plan executed exactly as written.

Known Stubs

None — all implemented functionality is fully wired.

Self-Check: PASSED

See below.