Add a test for pluralrules.resolvedOptions().pluralCategories.

test/intl402/PluralRules/prototype/resolvedOptions/pluralCategories.js

@@ -0,0 +1,29 @@
+// Copyright 2018 Igalia S.L. All rights reserved.
+// This code is governed by the license found in the LICENSE file.
+
+/*---
+esid: sec-Intl.PluralRules.prototype.resolvedOptions
+description: >
+    Tests that Intl.PluralRules.prototype.resolvedOptions creates a new array
+    for the pluralCategories property on every call.
+includes: [testIntl.js, propertyHelper.js, compareArray.js]
+---*/
+
+const allowedValues = ["zero", "one", "two", "few", "many", "other"];
+
+const pluralrules = new Intl.PluralRules();
+const options1 = pluralrules.resolvedOptions();
+const options2 = pluralrules.resolvedOptions();
+
+assert.notSameValue(options1.pluralCategories, options2.pluralCategories, "Should have different arrays");
+assert.compareArray(options1.pluralCategories, options2.pluralCategories, "Arrays should have same values");
+
+for (const category of options1.pluralCategories) {
+  assert(allowedValues.includes(category), `Found ${category}, expected one of ${allowedValues}`);
+}
+
+verifyProperty(options1, "pluralCategories", {
+  writable: true,
+  enumerable: true,
+  configurable: true,
+});