boa/boa_examples/src/bin/jsset.rs

// This example shows how to manipulate a Javascript Set using Rust code.
#![allow(clippy::bool_assert_comparison)]
use boa_engine::{object::builtins::JsSet, Context, JsValue};

fn main() -> Result<(), JsValue> {
    // New `Context` for a new Javascript executor.
    let context = &mut Context::default();

    // Create an empty set.
    let set = JsSet::new(context);

    assert_eq!(set.size(context)?, 0);
    set.add(5, context)?;
    assert_eq!(set.size(context)?, 1);
    set.add(10, context)?;
    assert_eq!(set.size(context)?, 2);
    set.clear(context)?;
    assert_eq!(set.size(context)?, 0);

    set.add("one", context)?;
    set.add("two", context)?;
    set.add("three", context)?;

    assert!(set.has("one", context)?);
    assert_eq!(set.has("One", context)?, false);

    set.delete("two", context)?;

    assert_eq!(set.has("two", context)?, false);

    set.clear(context)?;

    assert_eq!(set.has("one", context)?, false);
    assert_eq!(set.has("three", context)?, false);
    assert_eq!(set.size(context)?, 0);

    // Add a slice into a set;
    set.add_items(
        &[JsValue::new(1), JsValue::new(2), JsValue::new(3)],
        context,
    )?;
    // Will return 1, as one slice was added.
    assert_eq!(set.size(context)?, 1);

    // Make a new set from a slice
    let slice_set = JsSet::from_iter([JsValue::new(1), JsValue::new(2), JsValue::new(3)], context);
    // Will return 3, as each element of slice was added into the set.
    assert_eq!(slice_set.size(context)?, 3);

    set.clear(context)?;

    Ok(())
}