boa_engine/value/conversions/
either.rs

1//! Implementation of [`TryFromJs`] for [`Either`].
2//!
3//! This will try to deserialize for the [`Either::Left`] type
4//! first, and if it fails will try the [`Either::Right`] type.
5//!
6//! Upon failure of both, the second failure will be returned.
7#![cfg(feature = "either")]
8
9use crate::value::TryFromJs;
10use boa_engine::{Context, JsResult, JsValue};
11use either::Either;
12
13impl<L, R> TryFromJs for Either<L, R>
14where
15    L: TryFromJs,
16    R: TryFromJs,
17{
18    #[inline]
19    fn try_from_js(value: &JsValue, context: &mut Context) -> JsResult<Self> {
20        L::try_from_js(value, context)
21            .map(Self::Left)
22            .or_else(|_| R::try_from_js(value, context).map(Self::Right))
23    }
24}
25
26#[test]
27fn either() {
28    let v = JsValue::new(123);
29    let mut context = Context::default();
30
31    assert_eq!(
32        Either::<i32, i32>::try_from_js(&v, &mut context),
33        Ok(Either::Left(123))
34    );
35    assert_eq!(
36        Either::<i32, String>::try_from_js(&v, &mut context),
37        Ok(Either::Left(123))
38    );
39    assert_eq!(
40        Either::<String, i32>::try_from_js(&v, &mut context),
41        Ok(Either::Right(123))
42    );
43    assert!(Either::<String, String>::try_from_js(&v, &mut context).is_err());
44}
boa_engine/value/conversions/either.rs

boa_engine/value/conversions/
either.rs
