rhai/tests/closures.rs

#![cfg(not(feature = "no_function"))]
use rhai::{Dynamic, Engine, EvalAltResult, FnPtr, ParseErrorType, Scope, INT};
use std::any::TypeId;
use std::cell::RefCell;
use std::mem::take;
use std::rc::Rc;

#[cfg(not(feature = "no_object"))]
use rhai::Map;

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

    engine.register_raw_fn(
        "call_with_arg",
        [TypeId::of::<FnPtr>(), TypeId::of::<INT>()],
        |context, args| {
            let fn_ptr = args[0].take().cast::<FnPtr>();
            fn_ptr.call_raw(&context, None, [args[1].take()])
        },
    );

    #[cfg(not(feature = "no_object"))]
    assert_eq!(
        engine.eval::<INT>(
            "
                let addition = |x, y| { x + y };
                let curried = addition.curry(2);

                call_with_arg(curried, 40)
            "
        )?,
        42
    );

    Ok(())
}

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

    scope.push("x", 42 as INT);

    assert!(matches!(
        engine.compile_expression("|x| {}").unwrap_err().err_type(),
        ParseErrorType::BadInput(..)
    ));

    assert_eq!(
        engine.eval_with_scope::<INT>(
            &mut scope,
            "
                let f = || { x };
                f.call()
            ",
        )?,
        42
    );

    assert_eq!(
        engine.eval::<INT>(
            "
                let foo = #{ x: 42 };
                let f = || { this.x };
                foo.call(f)
            ",
        )?,
        42
    );

    assert_eq!(
        engine.eval::<INT>(
            "
                let x = 8;

                let res = |y, z| {
                    let w = 12;

                    return (|| x + y + z + w).call();
                }.curry(15).call(2);

                res + (|| x - 3).call()
            "
        )?,
        42
    );

    assert_eq!(
        engine.eval::<INT>(
            "
                let a = 41;
                let foo = |x| { a += x };
                foo.call(1);
                a
            "
        )?,
        42
    );

    assert!(engine.eval::<bool>(
        "
            let a = 41;
            let foo = |x| { a += x };
            a.is_shared()
        "
    )?);

    assert!(engine.eval::<bool>(
        "
            let a = 41;
            let foo = |x| { a += x };
            is_shared(a)
        "
    )?);

    engine.register_fn("plus_one", |x: INT| x + 1);

    assert_eq!(
        engine.eval::<INT>(
            "
                let a = 41;
                let f = || plus_one(a);
                f.call()
            "
        )?,
        42
    );

    assert_eq!(
        engine.eval::<INT>(
            "
                let a = 40;
                let f = |x| {
                    let f = |x| {
                        let f = |x| plus_one(a) + x;
                        f.call(x)
                    };
                    f.call(x)
                };
                f.call(1)
            "
        )?,
        42
    );

    assert_eq!(
        engine.eval::<INT>(
            "
                let a = 21;
                let f = |x| a += x;
                f.call(a);
                a
            "
        )?,
        42
    );

    engine.register_raw_fn(
        "custom_call",
        [TypeId::of::<INT>(), TypeId::of::<FnPtr>()],
        |context, args| {
            let func = take(args[1]).cast::<FnPtr>();

            func.call_raw(&context, None, [])
        },
    );

    assert_eq!(
        engine.eval::<INT>(
            "
                let a = 41;
                let b = 0;
                let f = || b.custom_call(|| a + 1);
                
                f.call()
            "
        )?,
        42
    );

    Ok(())
}

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

    engine.register_fn("foo", |x: INT, s: &str| s.len() as INT + x);
    engine.register_fn("bar", |x: INT, s: String| s.len() as INT + x);

    assert_eq!(
        engine.eval::<INT>(
            r#"
                let s = "hello";
                let f = || s;
                foo(1, s)
            "#
        )?,
        6
    );

    assert_eq!(
        engine.eval::<String>(
            r#"
                let s = "hello";
                let f = || s;
                let n = foo(1, s);
                s
            "#
        )?,
        "hello"
    );

    assert_eq!(
        engine.eval::<INT>(
            r#"
                let s = "hello";
                let f = || s;
                bar(1, s)
            "#
        )?,
        6
    );

    #[cfg(not(feature = "no_object"))]
    {
        let mut m = Map::new();
        m.insert("hello".into(), "world".into());
        let m = Dynamic::from(m).into_shared();

        engine.register_fn("baz", move || m.clone());

        assert!(!engine.eval::<bool>(
            "
                let m = baz();
                m.is_shared()
            "
        )?);

        assert_eq!(
            engine.eval::<String>(
                "
                let m = baz();
                m.hello
            "
            )?,
            "world"
        );

        assert_eq!(engine.eval::<String>("baz().hello")?, "world");
    }

    Ok(())
}

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

    assert_eq!(
        engine.eval::<INT>(
            "
                let a = 1;
                let b = 40;
                let foo = |x| { this += a + x };
                b.call(foo, 1);
                b
            "
        )?,
        42
    );

    assert!(matches!(
        *engine
            .eval::<INT>(
                "
                    let a = 20;
                    let foo = |x| { this += a + x };
                    a.call(foo, 1);
                    a
                "
            )
            .unwrap_err(),
        EvalAltResult::ErrorDataRace(..)
    ));

    Ok(())
}

type TestStruct = Rc<RefCell<INT>>;

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

    // Register API on TestStruct
    engine
        .register_type_with_name::<TestStruct>("TestStruct")
        .register_get_set(
            "data",
            |p: &mut TestStruct| *p.borrow(),
            |p: &mut TestStruct, value: INT| *p.borrow_mut() = value,
        )
        .register_fn("+=", |p1: &mut TestStruct, p2: TestStruct| {
            *p1.borrow_mut() += *p2.borrow()
        })
        .register_fn("-=", |p1: &mut TestStruct, p2: TestStruct| {
            *p1.borrow_mut() -= *p2.borrow()
        });

    let engine = engine; // Make engine immutable

    let code = r#"
        #{
            name: "A",
            description: "B",
            cost: 1,
            health_added: 0,
            action: |p1, p2| { p1 += p2 }
        }
    "#;

    let ast = engine.compile(code)?;
    let res = engine.eval_ast::<Map>(&ast)?;

    // Make closure
    let f = move |p1: TestStruct, p2: TestStruct| {
        let action_ptr = res["action"].clone_cast::<FnPtr>();
        let name = action_ptr.fn_name();
        engine.call_fn(&mut Scope::new(), &ast, name, (p1, p2))
    };

    // Test closure
    let p1 = Rc::new(RefCell::new(41));
    let p2 = Rc::new(RefCell::new(1));

    f(p1.clone(), p2)?;

    assert_eq!(*p1.borrow(), 42);

    Ok(())
}

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

    let ast = engine.compile(
        r#"
            let test = "hello";
            |x| test + x
        "#,
    )?;

    let fn_ptr = engine.eval_ast::<FnPtr>(&ast)?;

    let f = move |x: INT| fn_ptr.call::<String>(&engine, &ast, (x,));

    assert_eq!(f(42)?, "hello42");

    Ok(())
}

#[test]
#[cfg(not(feature = "no_closure"))]
#[cfg(not(feature = "sync"))]
fn test_closures_callback() -> Result<(), Box<EvalAltResult>> {
    type SingleNode = Rc<dyn Node>;

    trait Node {
        fn run(&self, x: INT) -> Result<INT, Box<EvalAltResult>>;
    }

    struct PhaserNode {
        func: Box<dyn Fn(INT) -> Result<INT, Box<EvalAltResult>>>,
    }

    impl Node for PhaserNode {
        fn run(&self, x: INT) -> Result<INT, Box<EvalAltResult>> {
            (self.func)(x)
        }
    }

    fn phaser(callback: impl Fn(INT) -> Result<INT, Box<EvalAltResult>> + 'static) -> impl Node {
        PhaserNode {
            func: Box::new(callback),
        }
    }

    let mut engine = Engine::new();

    let ast = Rc::new(engine.compile(
        "
            const FACTOR = 2;
            phaser(|x| x * FACTOR)
        ",
    )?);

    let shared_engine = Rc::new(RefCell::new(Engine::new_raw()));
    let engine2 = shared_engine.clone();
    let ast2 = ast.clone();

    engine.register_fn("phaser", move |fp: FnPtr| {
        let engine = engine2.clone();
        let ast = ast2.clone();

        let callback = Box::new(move |x: INT| fp.call(&engine.borrow(), &ast, (x,)));

        Rc::new(phaser(callback)) as SingleNode
    });

    *shared_engine.borrow_mut() = engine;

    let cb = shared_engine.borrow().eval_ast::<SingleNode>(&ast)?;

    assert_eq!(cb.run(21)?, 42);

    Ok(())
}