From f850a6fafc6cae76b57601cef891460fb3598064 Mon Sep 17 00:00:00 2001
From: Alexander Kryvomaz <akryvomaz@gmail.com>
Date: Sun, 1 Jul 2018 15:44:36 +0300
Subject: [PATCH] bindings for Function.prototype.bind()

---
 src/js.rs                        |  7 ++++++
 tests/all/js_globals/Function.rs | 40 ++++++++++++++++++++++++++++++++
 2 files changed, 47 insertions(+)

diff --git a/src/js.rs b/src/js.rs
index ced943054..e10d8d882 100644
--- a/src/js.rs
+++ b/src/js.rs
@@ -325,6 +325,13 @@ extern "C" {
     #[wasm_bindgen(method)]
     pub fn apply(this: &Function, context: &JsValue, args: &Array) -> Function;
 
+    /// The bind() method creates a new function that, when called, has its this keyword set to the provided value,
+    /// with a given sequence of arguments preceding any provided when the new function is called.
+    /// 
+    /// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function/bind
+    #[wasm_bindgen(method)]
+    pub fn bind(this: &Function, context: &JsValue) -> Function;
+
     /// The length property indicates the number of arguments expected by the function.
     ///
     /// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function/length
diff --git a/tests/all/js_globals/Function.rs b/tests/all/js_globals/Function.rs
index b54a26299..b5f32d5ba 100644
--- a/tests/all/js_globals/Function.rs
+++ b/tests/all/js_globals/Function.rs
@@ -38,6 +38,46 @@ fn apply() {
         .test()
 }
 
+#[test]
+fn bind() {
+    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 bind(this: &js::Function, context: &JsValue) -> js::Function {
+                this.bind(context)
+            }
+        "#,
+        )
+        .file(
+            "test.ts",
+            r#"
+            import * as assert from "assert";
+            import * as wasm from "./out";
+
+            export function test() {
+                const obj = {
+                    a: 0,
+                    fn: function () {
+                        return this.a + 1;
+                    }
+                }
+
+                const boundFn = wasm.bind(obj.fn, { a: 41 });
+                assert.equal(boundFn(), 42);
+            }
+        "#,
+        )
+        .test()
+}
+
 #[test]
 fn length() {
     project()