1 files changed, 81 insertions, 0 deletions
diff --git a/js/src/tests/Intl/DateTimeFormat/construct-newtarget.js b/js/src/tests/Intl/DateTimeFormat/construct-newtarget.js
new file mode 100644
index 000000000..bbc08c79a
--- /dev/null
+++ b/js/src/tests/Intl/DateTimeFormat/construct-newtarget.js
@@ -0,0 +1,81 @@
+// |reftest| skip-if(!this.hasOwnProperty("Intl"))
+
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+
+// Test subclassing %Intl.DateTimeFormat% works correctly.
+class MyDateTimeFormat extends Intl.DateTimeFormat {}
+
+var obj = new MyDateTimeFormat();
+assertEq(obj instanceof MyDateTimeFormat, true);
+assertEq(obj instanceof Intl.DateTimeFormat, true);
+assertEq(Object.getPrototypeOf(obj), MyDateTimeFormat.prototype);
+
+obj = Reflect.construct(MyDateTimeFormat, []);
+assertEq(obj instanceof MyDateTimeFormat, true);
+assertEq(obj instanceof Intl.DateTimeFormat, true);
+assertEq(Object.getPrototypeOf(obj), MyDateTimeFormat.prototype);
+
+obj = Reflect.construct(MyDateTimeFormat, [], MyDateTimeFormat);
+assertEq(obj instanceof MyDateTimeFormat, true);
+assertEq(obj instanceof Intl.DateTimeFormat, true);
+assertEq(Object.getPrototypeOf(obj), MyDateTimeFormat.prototype);
+
+obj = Reflect.construct(MyDateTimeFormat, [], Intl.DateTimeFormat);
+assertEq(obj instanceof MyDateTimeFormat, false);
+assertEq(obj instanceof Intl.DateTimeFormat, true);
+assertEq(Object.getPrototypeOf(obj), Intl.DateTimeFormat.prototype);
+
+
+// Set a different constructor as NewTarget.
+obj = Reflect.construct(MyDateTimeFormat, [], Array);
+assertEq(obj instanceof MyDateTimeFormat, false);
+assertEq(obj instanceof Intl.DateTimeFormat, false);
+assertEq(obj instanceof Array, true);
+assertEq(Object.getPrototypeOf(obj), Array.prototype);
+
+obj = Reflect.construct(Intl.DateTimeFormat, [], Array);
+assertEq(obj instanceof Intl.DateTimeFormat, false);
+assertEq(obj instanceof Array, true);
+assertEq(Object.getPrototypeOf(obj), Array.prototype);
+
+
+// The prototype defaults to %DateTimeFormatPrototype% if null.
+function NewTargetNullPrototype() {}
+NewTargetNullPrototype.prototype = null;
+
+obj = Reflect.construct(Intl.DateTimeFormat, [], NewTargetNullPrototype);
+assertEq(obj instanceof Intl.DateTimeFormat, true);
+assertEq(Object.getPrototypeOf(obj), Intl.DateTimeFormat.prototype);
+
+obj = Reflect.construct(MyDateTimeFormat, [], NewTargetNullPrototype);
+assertEq(obj instanceof MyDateTimeFormat, false);
+assertEq(obj instanceof Intl.DateTimeFormat, true);
+assertEq(Object.getPrototypeOf(obj), Intl.DateTimeFormat.prototype);
+
+
+// "prototype" property is retrieved exactly once.
+var trapLog = [], getLog = [];
+var ProxiedConstructor = new Proxy(Intl.DateTimeFormat, new Proxy({
+    get(target, propertyKey, receiver) {
+        getLog.push(propertyKey);
+        return Reflect.get(target, propertyKey, receiver);
+    }
+}, {
+    get(target, propertyKey, receiver) {
+        trapLog.push(propertyKey);
+        return Reflect.get(target, propertyKey, receiver);
+    }
+}));
+
+obj = Reflect.construct(Intl.DateTimeFormat, [], ProxiedConstructor);
+assertEqArray(trapLog, ["get"]);
+assertEqArray(getLog, ["prototype"]);
+assertEq(obj instanceof Intl.DateTimeFormat, true);
+assertEq(Object.getPrototypeOf(obj), Intl.DateTimeFormat.prototype);
+
+
+if (typeof reportCompare === "function")
+    reportCompare(0, 0);