add binding for lastIndexOf

src/js.rs

@@ -105,4 +105,11 @@ extern {
     /// http://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/indexOf
     #[wasm_bindgen(method, js_name = indexOf)]
     pub fn index_of(this: &Array, value: JsValue, from_index: i32) -> i32;
+
+    /// The lastIndexOf() method returns the last index at which a given element can be found in the array, or -1 if it is not present.
+    /// The array is searched backwards, starting at fromIndex.
+    ///
+    /// http://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/lastIndexOf
+    #[wasm_bindgen(method, js_name = lastIndexOf)]
+    pub fn last_index_of(this: &Array, value: JsValue, from_index: i32) -> i32;
 }

tests/all/js_globals/Array.rs

@@ -39,3 +39,41 @@ fn index_of() {
         "#)
         .test()
 }
+
+#[test]
+fn last_index_of() {
+    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 get_last_index_of(this: &js::Array, value: JsValue, from_index: i32) -> i32 {
+                this.last_index_of(value, from_index)
+            }
+
+        "#)
+        .file("test.ts", r#"
+            import * as assert from "assert";
+            import * as wasm from "./out";
+
+            export function test() {
+                let characters = ["a", "x", "c", "x", "n"];
+                let index = wasm.get_last_index_of(characters, "x", 5);
+                let notFoundIndex = wasm.get_last_index_of(characters, "z", 5);
+
+                assert.equal(index, 3);
+                assert.equal(notFoundIndex, -1);
+
+                let withFromIndex = wasm.get_last_index_of(characters, "x", 2);
+                let withFromIndexNotFound = wasm.get_last_index_of(characters, "x", 0);
+
+                assert.equal(withFromIndex, 1);
+                assert.equal(withFromIndexNotFound, -1);
+            }
+        "#)
+        .test()
+}