use rhai::{Engine, EvalAltResult, INT}; #[test] fn test_decrement() -> Result<(), Box<EvalAltResult>> { let engine = Engine::new(); assert_eq!(engine.eval::<INT>("let x = 10; x -= 7; x")?, 3); assert!(matches!( *engine.eval::<String>(r#"let s = "test"; s -= "ing"; s"#).expect_err("expects error"), EvalAltResult::ErrorFunctionNotFound(err, _) if err == "- (&str | ImmutableString | String, &str | ImmutableString | String)" )); Ok(()) }