rhai/tests/eval.rs

use rhai::{Engine, EvalAltResult, LexError, ParseErrorType, RegisterFn, Scope, INT};

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

    assert_eq!(engine.eval::<INT>(r#"eval("40 + 2")"#)?, 42);

    Ok(())
}

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

    assert_eq!(
        engine.eval::<INT>(
            r#"
                let x = 999;

                eval("let x = x + 123");

                let y = if x > 0 {
                    eval("let x = 42");
                    x
                } else {
                    0
                };

                x + y
            "#
        )?,
        1164
    );

    Ok(())
}

#[test]
#[cfg(not(feature = "no_function"))]
fn test_eval_function() -> Result<(), Box<EvalAltResult>> {
    let engine = Engine::new();
    let mut scope = Scope::new();

    assert_eq!(
        engine.eval_with_scope::<INT>(
            &mut scope,
            r#"
                let x = 10;

                fn foo(x) { x += 12; x }

                let script = "let y = x;";      // build a script
                script +=    "y += foo(y);";
                script +=    "x + y";

                eval(script) + x + y
            "#
        )?,
        84
    );

    assert_eq!(
        scope
            .get_value::<INT>("x")
            .expect("variable x should exist"),
        10
    );

    assert_eq!(
        scope
            .get_value::<INT>("y")
            .expect("variable y should exist"),
        32
    );

    assert!(scope.contains("script"));
    assert_eq!(scope.len(), 3);

    Ok(())
}

#[test]
#[cfg(not(feature = "no_function"))]
fn test_eval_override() -> Result<(), Box<EvalAltResult>> {
    let engine = Engine::new();

    assert_eq!(
        engine.eval::<String>(
            r#"
                fn eval(x) { x }    // reflect the script back

                eval("40 + 2")
            "#
        )?,
        "40 + 2"
    );

    let mut engine = Engine::new();

    // Reflect the script back
    engine.register_fn("eval", |script: &str| script.to_string());

    assert_eq!(engine.eval::<String>(r#"eval("40 + 2")"#)?, "40 + 2");

    Ok(())
}

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

    engine.disable_symbol("eval");

    assert!(matches!(
        *engine
            .compile(r#"eval("40 + 2")"#)
            .expect_err("should error")
            .0,
        ParseErrorType::BadInput(LexError::ImproperSymbol(err, _)) if err == "eval"
    ));

    Ok(())
}