intl: Tests for default options tweak proposal (#1220)

Tests for ECMA 402 PR https://github.com/tc39/ecma402/pull/170
The tests on Date/DateTimeFormat are valid without the PR.

test/intl402/Collator/default-options-object-prototype.js

+// Copyright (C) 2017 Daniel Ehrenberg. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-initializecollator
+description: >
+  Monkey-patching Object.prototype does not change the default
+  options for Collator as a null prototype is used.
+info: >
+  InitializeCollator ( collator, locales, options )
+
+    1. If _options_ is *undefined*, then
+      1. Let _options_ be ObjectCreate(*null*).
+---*/
+
+let defaultSensitivity = new Intl.Collator("en").resolvedOptions().sensitivity;
+
+Object.prototype.sensitivity = "base";
+let collator = new Intl.Collator("en");
+assert.sameValue(collator.resolvedOptions().sensitivity, defaultSensitivity);

test/intl402/Date/prototype/toLocaleString/default-options-object-prototype.js

+// Copyright (C) 2017 Daniel Ehrenberg. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-todatetimeoptions
+description: >
+  Monkey-patching Object.prototype does not change the default
+  options for DateTimeFormat as a null prototype is used.
+info: >
+  ToDateTimeOptions ( options, required, defaults )
+
+  1. If options is undefined, let options be null; otherwise let options be ? ToObject(options).
+  1. Let options be ObjectCreate(options).
+---*/
+
+if (new Intl.DateTimeFormat("en").resolvedOptions().locale === "en") {
+  Object.prototype.year = "2-digit";
+  assert.notSameValue(new Date().toLocaleString("en").length, 2);
+}

test/intl402/DateTimeFormat/default-options-object-prototype.js

+// Copyright (C) 2017 Daniel Ehrenberg. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-todatetimeoptions
+description: >
+  Monkey-patching Object.prototype does not change the default
+  options for DateTimeFormat as a null prototype is used.
+info: >
+  ToDateTimeOptions ( options, required, defaults )
+
+  1. If options is undefined, let options be null; otherwise let options be ? ToObject(options).
+  1. Let options be ObjectCreate(options).
+---*/
+
+let defaultYear = new Intl.DateTimeFormat("en").resolvedOptions().year;
+
+Object.prototype.year = "2-digit";
+let formatter = new Intl.DateTimeFormat("en");
+assert.sameValue(formatter.resolvedOptions().year, defaultYear);

test/intl402/Number/prototype/toLocaleString/default-options-object-prototype.js

+// Copyright (C) 2017 Daniel Ehrenberg. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-initializenumberformat
+description: >
+  Monkey-patching Object.prototype does not change the default
+  options for NumberFormat as a null prototype is used.
+info: >
+  InitializeNumberFormat ( numberFormat, locales, options )
+
+    1. If _options_ is *undefined*, then
+      1. Let _options_ be ObjectCreate(*null*).
+---*/
+
+if (new Intl.NumberFormat("en").resolvedOptions().locale === "en") {
+  Object.prototype.maximumFractionDigits = 1;
+  assert.sameValue(1.23.toLocaleString("en"), "1.23");
+}

test/intl402/NumberFormat/default-options-object-prototype.js

+// Copyright (C) 2017 Daniel Ehrenberg. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-initializenumberformat
+description: >
+  Monkey-patching Object.prototype does not change the default
+  options for NumberFormat as a null prototype is used.
+info: >
+  InitializeNumberFormat ( numberFormat, locales, options )
+
+    1. If _options_ is *undefined*, then
+      1. Let _options_ be ObjectCreate(*null*).
+---*/
+
+let defaultMaximumFractionDigits =
+    new Intl.NumberFormat("en").resolvedOptions().maximumFractionDigits;
+
+Object.prototype.maximumFractionDigits = 1;
+let formatter = new Intl.NumberFormat("en");
+assert.sameValue(formatter.resolvedOptions().maximumFractionDigits,
+                 defaultMaximumFractionDigits);

test/intl402/String/prototype/localeCompare/default-options-object-prototype.js

+// Copyright (C) 2017 Daniel Ehrenberg. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-initializecollator
+description: >
+  Monkey-patching Object.prototype does not change the default
+  options for Collator as a null prototype is used.
+info: >
+  InitializeCollator ( collator, locales, options )
+
+    1. If _options_ is *undefined*, then
+      1. Let _options_ be ObjectCreate(*null*).
+---*/
+
+if (new Intl.Collator("en").resolvedOptions().locale === "en") {
+  Object.prototype.sensitivity = "base";
+  assert.sameValue("a".localeCompare("A"), -1);
+}