add binding for slice

src/js.rs

@@ -118,4 +118,12 @@ extern {
     /// http://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/join
     #[wasm_bindgen(method)]
     pub fn join(this: &Array, delimiter: &str) -> String;
+
+    /// The slice() method returns a shallow copy of a portion of an array into a new array
+    /// object selected from begin to end (end not included).
+    /// The original array will not be modified.
+    /// 
+    /// http://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/slice
+    #[wasm_bindgen(method)]
+    pub fn slice(this: &Array, start: u32, end: u32) -> Array;
 }

tests/all/js_globals/Array.rs

@@ -109,3 +109,33 @@ fn join() {
         "#)
         .test()
 }
+
+#[test]
+fn slice() {
+    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 create_slice(this: &js::Array, start: u32, end: u32) -> js::Array {
+                this.slice(start, end)
+            }
+        "#)
+        .file("test.ts", r#"
+            import * as assert from "assert";
+            import * as wasm from "./out";
+
+            export function test() {
+                let characters = ["a", "c", "x", "n", 1, "8"];
+                let subset = wasm.create_slice(characters, 1, 3);
+
+                assert.equal(subset[0], "c");
+                assert.equal(subset[1], "x");
+            }
+        "#)
+        .test()
+}