wasm-mutate 0.246.2

A WebAssembly test case mutator
Documentation
use wasm_mutate::{ErrorKind, WasmMutate};
use wasmparser::Validator;

fn validate(validator: &mut Validator, bytes: &[u8]) {
    let err = match validator.validate_all(bytes) {
        Ok(_) => return,
        Err(e) => e,
    };
    drop(std::fs::write("test.wasm", &bytes));
    if let Ok(text) = wasmprinter::print_bytes(bytes) {
        drop(std::fs::write("test.wat", &text));
    }

    panic!("Wasm failed to validate: {err:?}");
}

#[test]
fn integration_test() {
    let _ = env_logger::try_init();

    let wat = r#"
        (module
            (func (export "exported_func")
                nop
                i32.const 42
                if
                    i32.const 98
                    drop
                end
            )
        )
    "#;
    let original = &wat::parse_str(wat).unwrap();

    let mut mutator = WasmMutate::default();
    mutator.fuel(1000);
    mutator.seed(0);

    // seed is zero, which means first mutator
    let start = std::time::Instant::now();
    let mut count = 0;

    for _ in 0..100 {
        let it = match mutator.run(original) {
            Ok(it) => it,
            Err(e) => match e.kind() {
                ErrorKind::NoMutationsApplicable => continue,
                ErrorKind::OutOfFuel => break,
                _ => panic!("{}", e),
            },
        };
        for mutated in it.take(100) {
            // Down here is the validation for the correct mutation
            let mutated = mutated.unwrap();
            let text = wasmprinter::print_bytes(&mutated).unwrap();
            println!("{text}");
            let mut validator = Validator::new();
            validate(&mut validator, &mutated);
            count += 1;
        }
    }

    let elapsed = start.elapsed();
    println!(
        "Generate {} modules in {}.{:03} seconds",
        count,
        elapsed.as_secs(),
        elapsed.subsec_millis()
    );
}