diff --git a/src/js.rs b/src/js.rs index 08143ad93..24789b66b 100644 --- a/src/js.rs +++ b/src/js.rs @@ -216,6 +216,16 @@ extern "C" { #[wasm_bindgen(method, getter, structural)] pub fn length(this: &Array) -> u32; + /// map calls a provided callback function once for each element in an array, + /// in order, and constructs a new array from the results. callback is invoked + /// only for indexes of the array which have assigned values, including undefined. + /// It is not called for missing elements of the array (that is, indexes that have + /// never been set, which have been deleted or which have never been assigned a value). + /// + /// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/map + #[wasm_bindgen(method)] + pub fn map(this: &Array, predicate: &mut FnMut(JsValue, u32, Array) -> JsValue) -> Array; + /// The pop() method removes the last element from an array and returns that /// element. This method changes the length of the array. /// diff --git a/tests/all/js_globals/Array.rs b/tests/all/js_globals/Array.rs index 33b01723a..a8ab5477a 100644 --- a/tests/all/js_globals/Array.rs +++ b/tests/all/js_globals/Array.rs @@ -796,3 +796,37 @@ fn find() { ) .test() } + +#[test] +fn map() { + project() + .file( + "src/lib.rs", + r#" + #![feature(proc_macro, wasm_custom_section)] + + extern crate wasm_bindgen; + use wasm_bindgen::prelude::*; + use wasm_bindgen::js; + use JsValue; + + #[wasm_bindgen] + pub fn array_map(array: &js::Array) -> js::Array { + array.map(&mut |el, _, _| JsValue::from_f64(el.as_f64().unwrap().sqrt())) + } + "#, + ) + .file( + "test.js", + r#" + import * as assert from "assert"; + import * as wasm from "./out"; + + export function test() { + const numbers = [1, 4, 9]; + assert.deepStrictEqual(wasm.array_map(numbers), [1, 2, 3]); + } + "#, + ) + .test() +}