Instruction file imported from mkhomutov/Persatrix (.github/instructions/rust-cli.instructions.md). Copyright stays with the author.

Rust CLI

• Argument parsing: clap v4 derive macros. See existing Command enum in cli/src/main.rs.
• Exhaustive match: No catch-all _ on command enums. Adding a command must cause a compile error until all match arms are implemented.
• Async runtime: tokio with #[tokio::main].
• Thin client: CLI is a REST client to the orchestrator at --server (default http://localhost:8080). All business logic lives server-side.
• Output: tabled for tables, indicatif for progress bars, colored for terminal colors.
• YAML: serde_yml (maintained successor to serde_yaml).
• Comments in plain English. Write comments a non-programmer could follow — say what the code does and why it matters, briefly. Full rules: Documentation Guide § Writing Style.

TDD (from v0.3.0 onward)

• Red-Green-Refactor: Write a failing #[test] (or #[tokio::test]) before implementing the function. Confirm the red state with cargo test -p persatrix (the package name in cli/Cargo.toml) or simply cargo test from cli/.
• Unit test placement: Inline #[cfg(test)] mod tests { ... } at the bottom of the source file being tested.
• Integration tests: Place in cli/tests/ (create the directory on first use) as separate .rs files. These test CLI argument parsing and output formatting end-to-end without a live server (use a mock HTTP server or mockito).
• HTTP calls: Mock the orchestrator REST API in unit tests — do not make real network calls. Inject the base URL via the --server flag or a test helper that binds mockito. mockito is not currently declared in cli/Cargo.toml; add mockito = "1" to [dev-dependencies] on first use (matches the lazy-add pattern called out in that file's comments).
• New commands: Before adding a Command variant, write at least one test that asserts the expected output format; implement until it passes.