ObjectPrototype: Implement Object.assign from ES6

[ChangeLog][QtQml] Object.assign from the ES6 specification is now
implemented.

This fixes another bunch of failures on test/built-ins/Object/, from 375
to 348 failures.

Change-Id: I815b0f3b43efcd6af8f24b26c5215ce9943b3efa
Reviewed-by: Simon Hausmann <[email protected]>

2 files changed, 48 insertions, 1 deletions

diff --git a/src/qml/jsruntime/qv4objectproto.cpp b/src/qml/jsruntime/qv4objectproto.cpp
index d9bad4eb0c..d8063c64de 100644
--- a/src/qml/jsruntime/qv4objectproto.cpp
+++ b/src/qml/jsruntime/qv4objectproto.cpp
@@ -1,5 +1,6 @@
 /****************************************************************************
 **
+** Copyright (C) 2017 Crimson AS <[email protected]>
 ** Copyright (C) 2016 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
@@ -93,6 +94,7 @@ void ObjectPrototype::init(ExecutionEngine *v4, Object *ctor)
     ctor->defineDefaultProperty(QStringLiteral("getPrototypeOf"), method_getPrototypeOf, 1);
     ctor->defineDefaultProperty(QStringLiteral("getOwnPropertyDescriptor"), method_getOwnPropertyDescriptor, 2);
     ctor->defineDefaultProperty(QStringLiteral("getOwnPropertyNames"), method_getOwnPropertyNames, 1);
+    ctor->defineDefaultProperty(QStringLiteral("assign"), method_assign, 2);
     ctor->defineDefaultProperty(QStringLiteral("create"), method_create, 2);
     ctor->defineDefaultProperty(QStringLiteral("defineProperty"), method_defineProperty, 3);
     ctor->defineDefaultProperty(QStringLiteral("defineProperties"), method_defineProperties, 2);
@@ -156,6 +158,50 @@ void ObjectPrototype::method_getOwnPropertyNames(const BuiltinFunction *, Scope
     scope.result = getOwnPropertyNames(scope.engine, callData->args[0]);
 }
 
+// 19.1.2.1
+void ObjectPrototype::method_assign(const BuiltinFunction *, Scope &scope, CallData *callData)
+{
+    ScopedObject to(scope, callData->args[0].toObject(scope.engine));
+    CHECK_EXCEPTION();
+
+    if (callData->argc == 1) {
+        scope.result = to;
+        return;
+    }
+
+    for (int i = 1; i < callData->argc; ++i) {
+        if (callData->args[i].isUndefined() || callData->args[i].isNull())
+            continue;
+
+        ScopedObject from(scope, callData->args[i].toObject(scope.engine));
+        CHECK_EXCEPTION();
+        QV4::ScopedArrayObject keys(scope, QV4::ObjectPrototype::getOwnPropertyNames(scope.engine, from));
+        quint32 length = keys->getLength();
+
+        ScopedString nextKey(scope);
+        ScopedValue propValue(scope);
+        for (quint32 i = 0; i < length; ++i) {
+            nextKey = Value::fromReturnedValue(keys->getIndexed(i)).toString(scope.engine);
+
+            PropertyAttributes attrs;
+            ScopedProperty prop(scope);
+            from->getOwnProperty(nextKey, &attrs, prop);
+
+            if (attrs == PropertyFlag::Attr_Invalid)
+                continue;
+
+            if (!attrs.isEnumerable())
+                continue;
+
+            propValue = from->get(nextKey);
+            to->put(nextKey, propValue);
+            CHECK_EXCEPTION();
+        }
+    }
+
+    scope.result = to;
+}
+
 void ObjectPrototype::method_create(const BuiltinFunction *builtin, Scope &scope, CallData *callData)
 {
     ScopedValue O(scope, callData->argument(0));
@@ -676,7 +722,7 @@ ReturnedValue ObjectPrototype::fromPropertyDescriptor(ExecutionEngine *engine, c
     return o.asReturnedValue();
 }
 
-
+// es6: GetOwnPropertyKeys
 Heap::ArrayObject *ObjectPrototype::getOwnPropertyNames(ExecutionEngine *v4, const Value &o)
 {
     Scope scope(v4);
diff --git a/src/qml/jsruntime/qv4objectproto_p.h b/src/qml/jsruntime/qv4objectproto_p.h
index 1db8615511..44b54267f3 100644
--- a/src/qml/jsruntime/qv4objectproto_p.h
+++ b/src/qml/jsruntime/qv4objectproto_p.h
@@ -81,6 +81,7 @@ struct ObjectPrototype: Object
     static void method_getPrototypeOf(const BuiltinFunction *, Scope &scope, CallData *callData);
     static void method_getOwnPropertyDescriptor(const BuiltinFunction *, Scope &scope, CallData *callData);
     static void method_getOwnPropertyNames(const BuiltinFunction *, Scope &scope, CallData *callData);
+    static void method_assign(const BuiltinFunction *, Scope &scope, CallData *callData);
     static void method_create(const BuiltinFunction *, Scope &scope, CallData *callData);
     static void method_defineProperty(const BuiltinFunction *, Scope &scope, CallData *callData);
     static void method_defineProperties(const BuiltinFunction *, Scope &scope, CallData *callData);