dust/dust-lang/tests/variables.rs

use dust_lang::*;

#[test]
fn define_local() {
    let source = "let x = 42;";

    assert_eq!(
        compile(source),
        Ok(Chunk::with_data(
            None,
            FunctionType {
                type_parameters: None,
                value_parameters: None,
                return_type: Box::new(Type::None),
            },
            vec![
                (
                    Instruction::load_constant(Destination::Register(0), 0, false),
                    Span(8, 10)
                ),
                (Instruction::define_local(0, 0, false), Span(4, 5)),
                (Instruction::r#return(false), Span(11, 11))
            ],
            vec![ConcreteValue::Integer(42), ConcreteValue::string("x")],
            vec![Local::new(1, Type::Integer, false, Scope::default())]
        )),
    );

    assert_eq!(run(source), Ok(None));
}

#[test]
fn let_statement_expects_identifier() {
    let source = "let 1 = 2";

    assert_eq!(
        compile(source),
        Err(DustError::Compile {
            error: CompileError::ExpectedToken {
                expected: TokenKind::Identifier,
                found: Token::Integer("1").to_owned(),
                position: Span(4, 5)
            },
            source
        })
    );
}

#[test]
fn set_local() {
    let source = "let mut x = 41; x = 42; x";

    assert_eq!(
        compile(source),
        Ok(Chunk::with_data(
            None,
            FunctionType {
                type_parameters: None,
                value_parameters: None,
                return_type: Box::new(Type::Integer),
            },
            vec![
                (
                    Instruction::load_constant(Destination::Register(0), 0, false),
                    Span(12, 14)
                ),
                (Instruction::define_local(0, 0, true), Span(8, 9)),
                (
                    Instruction::load_constant(Destination::Register(1), 2, false),
                    Span(20, 22)
                ),
                (Instruction::set_local(1, 0), Span(16, 17)),
                (
                    Instruction::get_local(Destination::Register(2), 0),
                    Span(24, 25)
                ),
                (Instruction::r#return(true), Span(25, 25)),
            ],
            vec![
                ConcreteValue::Integer(41),
                ConcreteValue::string("x"),
                ConcreteValue::Integer(42)
            ],
            vec![Local::new(1, Type::Integer, true, Scope::default())]
        )),
    );

    assert_eq!(run(source), Ok(Some(ConcreteValue::Integer(42))));
}