Testing

Test Suite

Counts vary by feature flags; the async-runtime suite is only compiled when async-runtime is enabled.

Location	Count	Coverage
ion-core/tests/integration.rs	~462	Tree-walk interpreter, stdlib, host types, register_closure
ion-core/tests/cross_validate.rs	~205	Tree-walk ↔ VM parity
ion-core/tests/vm.rs	~161	VM-specific behavior
ion-core/tests/async_runtime.rs	~129	async-runtime native Tokio eval, host futures, timers, channels, callbacks
ion-core/tests/integration_async.rs	~14	End-to-end stdlib coverage under Engine::eval_async
ion-core/tests/edge_cases.rs	~65	Adversarial/edge cases
ion-core/tests/legacy_threaded_concurrency.rs	17	Legacy legacy-threaded-concurrency OS-thread sync-eval backend
ion-core/src/ (unit tests)	~28	Lexer, parser, hash, log, names, and stdlib manifest checks
Doctests	2+	Public crate examples

Cross-Validation Pattern

fn assert_both_eq(src: &str, expected: Value) {
    let tw_val = Engine::new().eval(src).unwrap();
    let vm_val = Engine::new().vm_eval(src).unwrap();
    assert_eq!(tw_val, expected);
    assert_eq!(vm_val, expected);
}

Running Tests

RUST_MIN_STACK=16777216 cargo test --workspace --all-features   # everything enabled
cargo test --all-features -p ion-core --test cross_validate   # just parity
cargo test -p ion-core --features async-runtime --test async_runtime   # native async runtime
cargo test -p ion-core --no-default-features --features legacy-threaded-concurrency --test legacy_threaded_concurrency
cargo test --all-features -p ion-core --test integration register_closure   # by name

cargo clippy --all-features --all-targets -- -D warnings
cargo fmt --all -- --check

Examples as tests

Example binaries are compiled by cargo test when their required features are active:

• cargo run --example embed -p ion-core — basic embedding
• cargo run --example tokio_host -p ion-core --features async-runtime — native Tokio async host

CI Pipeline (.github/workflows/ci.yml)

• test: cargo test --workspace --all-features
• clippy: --all-features --all-targets -- -D warnings
• fmt: cargo fmt --all -- --check
• build-lsp: cargo build -p ion-lsp --release

Fuzzing

• ion-core/fuzz/ directory (excluded from workspace)