Added tests for bind1()

Author: Samuel Warfield

crates/js-sys/src/lib.rs

@@ -1072,6 +1072,14 @@ extern "C" {
         arg3: &JsValue,
     ) -> Result<JsValue, JsValue>;
 
+    /// 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.
+    ///
+    /// [MDN documentation](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function/bind)
+    #[wasm_bindgen(method, js_name = bind)]
+    pub fn bind(this: &Function, context: &JsValue) -> 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.
     ///

crates/js-sys/tests/wasm/Function.js

@@ -5,6 +5,15 @@ exports.get_function_to_bind = function() {
 exports.get_value_to_bind_to = function() {
   return { x: 2 };
 };
+exports.list = function() {
+  return Array.prototype.slice.call(arguments);
+};
+exports.add_arguments = function() {
+    return function(arg1, arg2) {return arg1 + arg2}
+};
 exports.call_function = function(f) {
   return f();
 };
+exports.call_function_arg =  function(f, arg1) {
+  return f(arg1);
+};

crates/js-sys/tests/wasm/Function.rs

@@ -34,17 +34,42 @@ fn apply() {
 extern "C" {
     fn get_function_to_bind() -> Function;
     fn get_value_to_bind_to() -> JsValue;
+    fn list() -> Function;
+    fn add_arguments() -> Function;
     fn call_function(f: Function) -> JsValue;
+    fn call_function_arg(f: &Function, arg0: JsValue) -> JsValue;
+
 }
 
 #[wasm_bindgen_test]
 fn bind() {
+    let f = get_function_to_bind();
+    let new_f = f.bind(&get_value_to_bind_to());
+    assert_eq!(call_function(f), 1);
+    assert_eq!(call_function(new_f), 2);
+}
+
+#[wasm_bindgen_test]
+fn bind0() {
     let f = get_function_to_bind();
     let new_f = f.bind0(&get_value_to_bind_to());
     assert_eq!(call_function(f), 1);
     assert_eq!(call_function(new_f), 2);
 }
 
+#[wasm_bindgen_test]
+fn bind1() {
+    //let a_list = list();
+    //let prepended_list = a_list.bind1(&JsValue::NULL, &JsValue::from(2));
+
+    let adder = add_arguments();
+    let add_42 = adder.bind1(&JsValue::NULL, &JsValue::from(42));
+
+    assert_eq!(call_function_arg(&add_42, JsValue::from(1)), 43);
+    assert_eq!(call_function_arg(&add_42, JsValue::from(378)), 420);
+}
+
+
 #[wasm_bindgen_test]
 fn length() {
     assert_eq!(MAX.length(), 2);