Systemic Design Course: Rust workspace
Your engine lives in src/engine/ (generic rules machinery) and src/content/ (card definitions; only this directory may name specific cards). src/harness.rs is the thin adapter the course tests call; wire its todo!() stubs to your engine.
Tests live in tests/ and use use engine::harness::*;. Get a module's tests with node tools/start-module.mjs NN <this-dir> from the course repo.
cargo test
The crate has no dependencies yet. serde (with the derive feature) and serde_json are added at Module 5, when cards become JSON files in cards/.