feat(Map): add Map.set

src/js.rs

@@ -338,6 +338,13 @@ extern {
     /// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map
     #[wasm_bindgen(constructor)]
     pub fn new() -> Map;
+
+    /// The set() method adds or updates an element with a specified key 
+    /// and value to a Map object.
+    /// 
+    /// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map/set
+    #[wasm_bindgen(method)]
+    pub fn set(this: &Map, key: &JsValue, value: &JsValue) -> Map;
 }
 
 // Math

tests/all/js_globals/Map.rs

@@ -153,3 +153,32 @@ fn new() {
         "#)
         .test()
 }
+
+#[test]
+fn set() {
+    project()
+        .file("src/lib.rs", r#"
+            #![feature(proc_macro, wasm_custom_section)]
+
+            extern crate wasm_bindgen;
+            use wasm_bindgen::prelude::*;
+            use wasm_bindgen::js;
+
+            #[wasm_bindgen]
+            pub fn set(this: &js::Map, key: &JsValue, value: &JsValue) -> js::Map {
+                this.set(key, value)
+            }
+        "#)
+        .file("test.ts", r#"
+            import * as assert from "assert";
+            import * as wasm from "./out";
+
+            export function test() {
+                const map = new Map();
+                const newMap = wasm.set(map, 'foo', 'bar');
+                assert.equal(map.has('foo'), true);
+                assert.equal(newMap.has('foo'), true);
+            }
+        "#)
+        .test()
+}