rust-worker

name	rust-worker
description	Rust workspace crate worker for launa project — implements features with TDD, runs tests, verifies no regressions.

Rust Worker

NOTE: Startup and cleanup are handled by worker-base. This skill defines the WORK PROCEDURE.

When to Use This Skill

Features involving changes to workspace crates: launa-protocol, launa-ota, launa-sim, launa-integration-tests, launa-core. These are all desktop-testable Rust crates.

Required Skills

None. All work is done with Rust tooling (cargo test, cargo check, cargo fmt).

Work Procedure

1. Read Feature Description and Understand Scope

Read the feature description carefully. Identify which crate(s) need changes. Read the relevant source files before making any changes.

2. Write Tests First (RED)

Before any implementation, write tests that will fail:

1. Read the existing test structure in the target crate
2. Add new tests following the established naming conventions
3. Run cargo test -p <crate> and verify the NEW tests FAIL (expected)
4. Verify all EXISTING tests still pass

3. Implement (GREEN)

1. Make the minimal changes needed to make the new tests pass
2. Follow existing code patterns and conventions in the crate
3. Keep changes focused — one logical change per feature
4. All workspace crates are #![no_std] — never use std::
5. Use extern crate alloc and alloc:: collections where needed

4. Verify No Regressions

1. Run cargo test -p <crate> — all tests pass (new + existing)
2. Run cargo test --workspace — no regressions in any crate
3. Run cargo fmt — clean formatting
4. If the feature touches launa-ota, run cargo check -p launa-ota --no-default-features to verify no-alloc compilation

5. Update TASKS.md

Check off the completed task items by changing - [ ] to - [x] for the items this feature covers.

6. Commit

Commit with a focused message describing the change. Use imperative mood.

Key Conventions

• TDD: Tests written BEFORE implementation, always
• no_std: All workspace crates are #![no_std]
• Backward compatible: New features default to off/disabled
• No new dependencies: Use only existing crate dependencies
• Test structure: Integration tests in launa-integration-tests/src/lib.rs (test groups), sim tests in tests/sim_tests.rs
• SpaApp helpers: make_spaapp(), make_status_frame(), make_ready_frame() in integration tests

Example Handoff

{
  "salientSummary": "Added failure injection to MockOta (fail_on_begin, fail_on_write_after, fail_on_finalize) and OtaError context fields (byte_offset, address). All 6 new tests pass, all 359 existing tests still pass.",
  "whatWasImplemented": "MockOta failure injection fields, OtaError thiserror derive with context fields, MAX_FIRMWARE_SIZE constant, in_progress guard. 8 new tests added to launa-ota.",
  "whatWasLeftUndone": "",
  "verification": {
    "commandsRun": [
      { "command": "cargo test -p launa-ota", "exitCode": 0, "observation": "All 14 tests passed" },
      { "command": "cargo test --workspace", "exitCode": 0, "observation": "All 367 tests passed" },
      { "command": "cargo check -p launa-ota --no-default-features"     
             
    
     
  
   
     
          
             
             
             
             
             
             
             
             
       
    
  
   

When to Return to Orchestrator

• Feature requires changes to app/ crate (ESP32-only, can't test on desktop)
• Need to add a new workspace dependency not already in Cargo.toml
• Existing tests fail and the fix is outside the feature's scope
• Requirements are ambiguous — check feature description and AGENTS.md first