rust-app-worker

name	rust-app-worker
description	Implements features in the ESP32 app/ crate and cross-cutting changes (app + workspace crates, CI, gitignore, xtask). Uses TDD where possible; cargo +esp check for app/ verification.

Rust App Worker

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

When to Use This Skill

Features that involve the app/ crate (ESP32 firmware binary), cross-cutting changes spanning app/ and workspace crates, CI pipeline setup, .gitignore changes, and xtask modifications.

Required Skills

None.

Work Procedure

1. Read context: Read the feature description, mission.md, AGENTS.md, and .factory/library/architecture.md. Understand what needs to change.

2. Investigate the codebase: Use Grep/Glob/Read to understand:

   • Exact file paths in app/src/ that need changes
   • How app/ integrates with workspace crates
   • ESP32-specific patterns (esp-hal, embassy, no_std with alloc)
   • Existing patterns in the affected files

3. Write tests where possible (RED):

   • For workspace crate changes: write failing tests first, then implement
   • For app/-only changes that can't be tested on desktop (esp-hal dependencies): write the implementation and verify with cargo +esp check
   • For CI/gitignore changes: verify the file exists and has correct content

4. Implement the fix (GREEN):

   • Follow existing patterns in the app/ crate
   • ESP32 heap is 32 KiB — avoid unbounded allocations
   • Use esp_println! or logging macros for output
   • For unsafe code: always add // SAFETY: comments
   • For CI: create .github/workflows/ci.yml

5. Verify:

   • For workspace changes: cargo test -p <crate> and cargo test --workspace
   • For app/ changes: cd C:\dev\launa\app && cargo +esp check
   • Full workspace: cargo check --workspace
   • Format: cargo fmt
   • Verify no new warnings from app/: cd C:\dev\launa\app && cargo +esp check 2>&1 — review for new warnings

6. Update TASKS.md: Change - [ ] to - [x] for completed tasks.

7. Commit: Stage and commit with descriptive message.

Example Handoff

{
  "salientSummary": "Added SAFETY comments to all UnsafeCell socket buffer dereferences in mqtt_client.rs. Added http:// scheme validation to parse_ota_url(). Both verified with cargo +esp check.",
  "whatWasImplemented": "Documented safety invariants for socket_rx_buf and socket_tx_buf UnsafeCell usage in app/src/mqtt_client.rs. Added URL scheme validation rejecting non-http:// URLs. Added warn! log on rejection.",
  "whatWasLeftUndone": "",
  "verification": {
    "commandsRun": [
      { "command": "cargo +esp check", "exitCode": 0, "observation": "app compiles with no new errors" },
      { "command": "cargo check --workspace", "exitCode": 0, "observation": "workspace typechecks" },
      { "command": "cargo fmt"     
    
     
  
   
     
  
   

When to Return to Orchestrator

• Feature depends on changes not yet made in a workspace crate
• cargo +esp check fails and the issue is in an esp-hal dependency (not fixable)
• Requirements need clarification about ESP32-specific behavior
• Changes needed are beyond the feature scope