Adding extended versions of without-utc-offset test.

Author: iamstolis

graal-js/src/com.oracle.truffle.js.test/js/without-utc-offset1.js

@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2020, 2020, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * Licensed under the Universal Permissive License v 1.0 as shown at http://oss.oracle.com/licenses/upl.
+ */
+
+/**
+ * This test is an extension of
+ * https://github.com/tc39/test262/blob/main/test/built-ins/Date/parse/without-utc-offset.js
+ * This extension checks also the desired behaviour for legacy dates
+ * (that are not covered by the specification).
+ */
+
+load('assert.js');
+
+const timezoneOffsetMS = new Date(0).getTimezoneOffset() * 60000;
+
+function check(string, expected) {
+    assertSame(expected, Date.parse(string));
+    assertSame(expected, new Date(string).getTime());
+}
+
+check('1970-01-01T00:00:00', timezoneOffsetMS);
+check('1970-01-01', 0);
+check('1970-01', 0);
+check('1970', 0);
+
+// Legacy format
+check('1-1-1970', 0);
+check('1-1-1970 00:00:00', timezoneOffsetMS);
+check('1/1/1970', 0);
+check('1/1/1970 00:00:00', timezoneOffsetMS);
+check('1970-01-1', 0);
+check('1970-1-01', 0);
+check('1970-1-1', 0);
+check('1970-1', 0);
+
+true;

graal-js/src/com.oracle.truffle.js.test/js/without-utc-offset2.js

@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2020, 2020, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * Licensed under the Universal Permissive License v 1.0 as shown at http://oss.oracle.com/licenses/upl.
+ */
+
+/**
+ * This test is an extension of
+ * https://github.com/tc39/test262/blob/main/test/built-ins/Date/parse/without-utc-offset.js
+ * This extension checks also the desired behaviour for legacy dates
+ * (that are not covered by the specification).
+ * 
+ * @option use-utc-for-legacy-dates=false
+ */
+
+load('assert.js');
+
+const timezoneOffsetMS = new Date(0).getTimezoneOffset() * 60000;
+
+function check(string, expected) {
+    assertSame(expected, Date.parse(string));
+    assertSame(expected, new Date(string).getTime());
+}
+
+check('1970-01-01T00:00:00', timezoneOffsetMS);
+check('1970-01-01', 0);
+check('1970-01', 0);
+check('1970', 0);
+
+// Legacy format
+check('1-1-1970', timezoneOffsetMS);
+check('1-1-1970 00:00:00', timezoneOffsetMS);
+check('1/1/1970', timezoneOffsetMS);
+check('1/1/1970 00:00:00', timezoneOffsetMS);
+check('1970-01-1', timezoneOffsetMS);
+check('1970-1-01', timezoneOffsetMS);
+check('1970-1-1', timezoneOffsetMS);
+check('1970-1', timezoneOffsetMS);
+
+true;