use rhai::{Engine, EvalAltResult}; #[test] fn test_decrement() -> Result<(), EvalAltResult> { let mut engine = Engine::new(); assert_eq!(engine.eval::("let x = 10; x -= 7; x")?, 3); let r = engine.eval::("let s = \"test\"; s -= \"ing\"; s"); match r { Err(EvalAltResult::ErrorFunctionNotFound(err, _)) if err.starts_with("- ") => (), _ => panic!(), } Ok(()) }