Visual Test Workflow

Iterating on visual UI changes requires a tight feedback loop: change code, build, capture screenshots, read the PNGs to verify, adjust, repeat. This skill documents the proven pattern using named pipes and stdin JSON commands.

Core Loop

1. Edit the Rust UI code
2. cargo build
3. Run a shell test script that drives the app via stdin JSON
4. Read the resulting PNG screenshots to visually verify
5. Adjust and repeat from step 1

Named Pipe Pattern

The app reads JSON commands from stdin. To send multiple commands over time, use a named pipe with a persistent file descriptor. This is the critical technique — without it the pipe closes after the first write and the app exits.