Merge pull request #285 from belfz/expose-bindings/object-property-is-enumerable

implements Object.prototype.propertyIsEnumerable() binding

src/js.rs

@@ -98,6 +98,13 @@ extern {
     /// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/isPrototypeOf
     #[wasm_bindgen(method, js_name = isPrototypeOf)]
     pub fn is_prototype_of(this: &Object, value: &JsValue) -> bool;
+
+    /// The propertyIsEnumerable() method returns a Boolean indicating
+    /// whether the specified property is enumerable.
+    /// 
+    /// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/propertyIsEnumerable
+    #[wasm_bindgen(method, js_name = propertyIsEnumerable)]
+    pub fn property_is_enumerable(this: &Object, property: &JsValue) -> bool;
 }
 
 // Array

tests/all/js_globals/Object.rs

@@ -118,3 +118,38 @@ fn is_prototype_of() {
         "#)
         .test()
 }
+
+#[test]
+fn property_is_enumerable() {
+    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 property_is_enumerable(obj: &js::Object, property: &JsValue) -> bool {
+                obj.property_is_enumerable(&property)
+            }
+        "#)
+        .file("test.ts", r#"
+            import * as assert from "assert";
+            import * as wasm from "./out";
+
+            export function test() {
+                assert(wasm.property_is_enumerable({ foo: 42 }, "foo"));
+                assert(wasm.property_is_enumerable({ 42: "foo" }, 42));
+                assert(!wasm.property_is_enumerable({}, 42));
+
+                const obj = {};
+                Object.defineProperty(obj, "foo", { enumerable: false });
+                assert(!wasm.property_is_enumerable(obj, "foo"));
+
+                const s = Symbol();
+                assert.ok(wasm.property_is_enumerable({ [s]: true }, s));
+            }
+        "#)
+        .test()
+}