Local development

Prerequisites

Tool	Install
Rust	rustup — the toolchain itself comes from rust-toolchain.toml
cargo tools	cargo install --locked cargo-nextest cargo-deny cargo-machete wasm-pack (or cargo binstall …)
Python	uv — it fetches the Python it needs
JavaScript	bun
Hooks	prek or pre-commit (uv tool install pre-commit)

Install the JS dependencies for the whole repository once, from the root:

bun install

Core crate (Rust)

cargo check --all-targets --all-features    # type check
cargo clippy --all-targets --all-features -- -D warnings
cargo fmt --all --check
cargo nextest run --workspace --all-features
cargo test --doc --workspace --all-features
# The core must stay runtime-free for the browser:
cargo check --target wasm32-unknown-unknown -p rusty_harness --no-default-features --features rt-wasm
# Supply chain:
cargo deny check
cargo machete

Python bindings

From crates/rusty-harness-py/:

uv sync                    # creates .venv with maturin, pytest, ruff, pyright
uv run maturin develop     # builds the extension into .venv; rerun after Rust changes
uv run pytest
uv run ruff check . && uv run ruff format --check .
uv run pyright

The type stub rusty_harness.pyi is generated from the Rust annotations. After changing an exported function, regenerate it and commit the result — CI fails on a stale stub:

cargo run -p rusty-harness-py --bin stub_gen

WASM and TypeScript bindings

From crates/rusty-harness-wasm/:

bun run build              # wasm-pack build for bundler, web and nodejs into dist/
bun run test               # vitest against the built package
bun run typecheck          # tsc --noEmit
wasm-pack test --node      # Rust-side wasm-bindgen tests
wasm-pack test --headless --chrome

From the root, bun run lint (oxlint, type-aware) and bun run format (oxfmt) cover every TypeScript, JSON, TOML and YAML file; bun run format:fix rewrites them.

Docs

bun run --cwd docs dev     # live preview at http://localhost:5173/rusty-harness/
bun run --cwd docs build
bun run lint:md
cargo doc --no-deps --all-features -p rusty_harness   # API reference