test(Intl.DurationFormat.prototype): check prototype attributes

test/intl402/DurationFormat/prototype/prototype_attributes.js

@@ -0,0 +1,15 @@
+// Copyright (C) 2021 Nikhil Singhal. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-Intl.DurationFormat.prototype
+description: Prototype attributes verification
+info: |
+  This property has the attributes { [[Writable]]: false, [[Enumerable]]: false, [[Configurable]]: false }.
+features: [Intl.DurationFormat.prototype]
+includes: [propertyHelper.js]
+---*/
+
+verifyNotEnumerable(Intl.DurationFormat, "prototype");
+verifyNotWritable(Intl.DurationFormat, "prototype");
+verifyNotConfigurable(Intl.DurationFormat, "prototype");

test/intl402/DurationFormat/prototype/toStringTag.js

@@ -0,0 +1,30 @@
+// Copyright (C) 2021 Nikhil Singhal. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-Intl.DurationFormat.prototype-@@tostringtag
+description: Checks prototype's toStringTag value
+info: |
+  The initial value of the @@toStringTag property is the string value "Intl.DurationFormat".
+  This property has the attributes { [[Writable]]: false, [[Enumerable]]: false, [[Configurable]]: true }.
+features: [Symbol.toStringTag]
+includes: [propertyHelper.js]
+---*/
+
+assert.sameValue(
+  Object.prototype.toString.call(Intl.DurationFormat.prototype),
+  '[object Intl.DurationFormat]',
+  'prototype - Initial value of @@toStringTag is not Intl.DurationFormat',
+);
+
+assert.sameValue(
+  Object.prototype.toString.call(new Intl.DurationFormat()),
+  '[object Intl.DurationFormat]',
+  'new call - Initial value of @@toStringTag is not Intl.DurationFormat',
+);
+
+const durationFormat = new Intl.DurationFormat();
+
+verifyNotEnumerable(durationFormat, Symbol.toStringTag);
+verifyNotWritable(durationFormat, Symbol.toStringTag);
+verifyConfigurable(durationFormat, Symbol.toStringTag);