Implement String repeat (#2904)

Co-authored-by: Tamas Keri tkeri@inf.u-szeged.hu
JerryScript-DCO-1.0-Signed-off-by: Daniella Barsony bella@inf.u-szeged.hu

tests/jerry/es2015/string-prototype-repeat.js

@@ -0,0 +1,71 @@
+/* Copyright JS Foundation and other contributors, http://js.foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// ES v6.0 21.1.3.13.6
+var z = "I am vengeance";
+try {
+  z.repeat (-1);
+  assert (false);
+} catch (e) {
+  assert (e instanceof RangeError);
+}
+
+// ES v6.0 21.1.3.13.7
+var x = "I am the night";
+try {
+  print(z.repeat (Infinity));
+  assert (false);
+} catch (e) {
+  assert (e instanceof RangeError);
+}
+
+// ES v6.0 21.1.3.13.8
+assert (z.repeat (0) === "");
+assert (z.repeat (NaN) === "");
+
+var y = "I am batman ";
+assert (y.repeat (3) === "I am batman I am batman I am batman ");
+
+assert (String.prototype.repeat.call ("My cat is awesome. ", 3) === "My cat is awesome. My cat is awesome. My cat is awesome. ");
+
+try {
+  String.prototype.repeat.call (undefined);
+  assert (false);
+} catch (e) {
+  assert (e instanceof TypeError);
+}
+
+try {
+  String.prototype.repeat.call (null);
+  assert (false);
+} catch (e) {
+  assert (e instanceof TypeError);
+}
+
+try {
+  String.prototype.repeat.call (undefined, "Sylveon");
+  assert (false);
+} catch (e) {
+  assert (e instanceof TypeError);
+}
+
+var a = Symbol ("Unicorn invasion.", 3);
+try {
+  String.prototype.repeat.call (a);
+  assert (false);
+} catch (e) {
+  assert (e instanceof TypeError);
+}
+