[builtins - object] Object.create

boa/src/builtins/object/mod.rs

@@ -410,6 +410,16 @@ pub fn make_object(_: &Value, args: &[Value], ctx: &mut Interpreter) -> ResultVa
     Ok(object)
 }
 
+/// Creates a new object from the provided prototype
+///
+/// https://tc39.es/ecma262/#sec-object.create
+/// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/create
+pub fn create_builtin(_: &Value, args: &[Value], _: &mut Interpreter) -> ResultValue {
+    let __proto__ = args.get(0).cloned().unwrap_or_else(Value::undefined);
+    let new_object = Value::new_object_from_prototype(__proto__, ObjectData::Ordinary);
+    Ok(new_object.into())
+}
+
 /// Uses the SameValue algorithm to check equality of objects
 pub fn is(_: &Value, args: &[Value], _: &mut Interpreter) -> ResultValue {
     let x = args.get(0).cloned().unwrap_or_else(Value::undefined);
@@ -517,6 +527,8 @@ pub fn create(global: &Value) -> Value {
 
     let object = make_constructor_fn("Object", 1, make_object, global, prototype, true);
 
+    // static methods of the builtin Object
+    make_builtin_fn(create_builtin, "create", &object, 1);
     make_builtin_fn(set_prototype_of, "setPrototypeOf", &object, 2);
     make_builtin_fn(get_prototype_of, "getPrototypeOf", &object, 1);
     make_builtin_fn(define_property, "defineProperty", &object, 3);

boa/src/builtins/object/tests.rs

@@ -1,5 +1,21 @@
 use crate::{exec::Interpreter, forward, realm::Realm};
 
+#[test]
+fn object_create() {
+    let realm = Realm::create();
+    let mut engine = Interpreter::new(realm);
+
+    let init = r#"
+        const foo = { a: 5 };
+        const bar = Object.create(foo);
+        "#;
+
+    forward(&mut engine, init);
+
+    assert_eq!(forward(&mut engine, "bar.a"), "5");
+    assert_eq!(forward(&mut engine, "Object.create.length"), "1");
+}
+
 #[test]
 fn object_is() {
     let realm = Realm::create();