rhai/tests/unary_minus.rs

use rhai::{Engine, EvalAltResult, INT};

#[test]
fn test_unary_minus() -> Result<(), EvalAltResult> {
    let mut engine = Engine::new();

    assert_eq!(engine.eval::<INT>("let x = -5; x")?, -5);
    assert_eq!(engine.eval::<INT>("fn neg(x) { -x } neg(5)")?, -5);
    assert_eq!(engine.eval::<INT>("5 - -+++--+-5")?, 0);

    Ok(())
}