stack-assembly 1.0.1

use crate::{Effect, Eval, Script, Value};

#[test]
fn read() {
    // `read` reads a word from memory at the given address, pushing it to the
    // stack. It does not modify the memory.

    let script = Script::compile("1 read 1 read");

    let mut eval = Eval::new();
    eval.memory.values[1] = Value::from(3);
    let (effect, _) = eval.run(&script);

    assert_eq!(effect, Effect::OutOfOperators);
    assert_eq!(eval.operand_stack.to_u32_slice(), &[3, 3]);
}

#[test]
fn read_triggers_effect_on_out_of_bounds_access() {
    // If the address passed to `read` is out of bounds, that triggers the
    // respective effect.

    let script = Script::compile("1025 read");

    let mut eval = Eval::new();
    assert!(
        eval.memory.values.len() < 1025,
        "Test can't work, because it makes wrong assumption about memory size.",
    );

    let (effect, _) = eval.run(&script);
    assert_eq!(effect, Effect::InvalidAddress);
    assert_eq!(eval.operand_stack.to_u32_slice(), &[]);
}

#[test]
fn write() {
    // `write` writes a word to memory at the given address.

    let script = Script::compile("1 3 write");

    let mut eval = Eval::new();
    let (effect, _) = eval.run(&script);

    assert_eq!(effect, Effect::OutOfOperators);
    assert_eq!(eval.operand_stack.to_u32_slice(), &[]);
    assert_eq!(eval.memory.values[1], Value::from(3));
}

#[test]
fn write_triggers_effect_on_out_of_bounds_access() {
    // If the address passed to `write` is out of bounds, that triggers the
    // respective effect.

    let script = Script::compile("1025 3 write");

    let mut eval = Eval::new();
    assert!(
        eval.memory.values.len() < 1025,
        "Test can't work, because it makes wrong assumption about memory size.",
    );

    let (effect, _) = eval.run(&script);
    assert_eq!(effect, Effect::InvalidAddress);
    assert_eq!(eval.operand_stack.to_u32_slice(), &[]);
}