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

jerry-core/ecma/builtin-objects/ecma-builtin-string-prototype.c

@@ -2095,6 +2095,90 @@ ecma_builtin_string_prototype_object_trim (ecma_value_t this_arg) /**< this argu
   return ret_value;
 } /* ecma_builtin_string_prototype_object_trim */
 
+#if ENABLED (JERRY_ES2015_BUILTIN)
+
+/**
+ * The String.prototype object's 'repeat' routine
+ *
+ * See also:
+ *          ECMA-262 v6, 21.1.3.13
+ *
+ * @return ecma value
+ *         Returned value must be freed with ecma_free_value.
+ */
+static ecma_value_t
+ecma_builtin_string_prototype_object_repeat (ecma_value_t this_arg, /**< this argument */
+                                             ecma_value_t count) /**< times to repeat */
+{
+  /* 1 */
+  ecma_value_t check_coercible_value = ecma_op_check_object_coercible (this_arg);
+
+  if (ECMA_IS_VALUE_ERROR (check_coercible_value))
+  {
+    return check_coercible_value;
+  }
+
+  /* 2, 3 */
+  ecma_value_t to_string_val = ecma_op_to_string (this_arg);
+
+  if (ECMA_IS_VALUE_ERROR (to_string_val))
+  {
+    return to_string_val;
+  }
+
+  ecma_string_t *original_string_p = ecma_get_string_from_value (to_string_val);
+  ecma_string_t *ret_string_p;
+
+  /* 4 */
+  ecma_number_t length_number;
+  ecma_value_t length_value = ecma_get_number (count, &length_number);
+
+  /* 5 */
+  if (ECMA_IS_VALUE_ERROR (length_value))
+  {
+    ecma_deref_ecma_string (original_string_p);
+    return length_value;
+  }
+
+  int32_t length = ecma_number_to_int32 (length_number);
+
+  bool isNan = ecma_number_is_nan (length_number);
+
+  /* 6, 7 */
+  if (length < 0 || (!isNan && ecma_number_is_infinity (length_number)))
+  {
+    ecma_deref_ecma_string (original_string_p);
+    return ecma_raise_range_error (ECMA_ERR_MSG ("Invalid count value"));
+  }
+
+  if (length == 0 || isNan)
+  {
+    ecma_deref_ecma_string (original_string_p);
+    return ecma_make_magic_string_value (LIT_MAGIC_STRING__EMPTY);
+  }
+
+  lit_utf8_size_t size = ecma_string_get_utf8_size (original_string_p);
+  lit_utf8_size_t total_size = size * (lit_utf8_size_t) length;
+
+  JMEM_DEFINE_LOCAL_ARRAY (str_buffer, total_size, lit_utf8_byte_t);
+
+  lit_utf8_byte_t *buffer_ptr = str_buffer;
+
+  for (int32_t n = 0; n < length; n++)
+  {
+    buffer_ptr += ecma_string_copy_to_cesu8_buffer (original_string_p, buffer_ptr,
+                                                    (lit_utf8_size_t) (size));
+  }
+
+  ret_string_p = ecma_new_ecma_string_from_utf8 (str_buffer, (lit_utf8_size_t) (buffer_ptr - str_buffer));
+  JMEM_FINALIZE_LOCAL_ARRAY (str_buffer);
+  ecma_deref_ecma_string (original_string_p);
+
+  return ecma_make_string_value (ret_string_p);
+} /* ecma_builtin_string_prototype_object_repeat */
+
+#endif /* ENABLED (JERRY_ES2015_BUILTIN) */
+
 #if ENABLED (JERRY_BUILTIN_ANNEXB)
 
 /**

jerry-core/ecma/builtin-objects/ecma-builtin-string-prototype.inc.h

@@ -55,6 +55,10 @@ ROUTINE (LIT_MAGIC_STRING_REPLACE, ecma_builtin_string_prototype_object_replace,
 ROUTINE (LIT_MAGIC_STRING_SEARCH, ecma_builtin_string_prototype_object_search, 1, 1)
 #endif /* ENABLED (JERRY_BUILTIN_REGEXP) */
 
+#if ENABLED (JERRY_ES2015_BUILTIN)
+ROUTINE (LIT_MAGIC_STRING_REPEAT, ecma_builtin_string_prototype_object_repeat, 1, 1)
+#endif /* ENABLED (JERRY_ES2015_BUILTIN) */
+
 ROUTINE (LIT_MAGIC_STRING_SPLIT, ecma_builtin_string_prototype_object_split, 2, 2)
 ROUTINE (LIT_MAGIC_STRING_SUBSTRING, ecma_builtin_string_prototype_object_substring, 2, 2)
 ROUTINE (LIT_MAGIC_STRING_TO_LOWER_CASE_UL, ecma_builtin_string_prototype_object_to_lower_case, 0, 0)

jerry-core/lit/lit-magic-strings.inc.h

@@ -300,6 +300,9 @@ LIT_MAGIC_STRING_DEF (LIT_MAGIC_STRING_REDUCE, "reduce")
 #if ENABLED (JERRY_ES2015_BUILTIN_PROMISE)
 LIT_MAGIC_STRING_DEF (LIT_MAGIC_STRING_REJECT, "reject")
 #endif
+#if ENABLED (JERRY_BUILTIN_STRING) && ENABLED (JERRY_ES2015_BUILTIN)
+LIT_MAGIC_STRING_DEF (LIT_MAGIC_STRING_REPEAT, "repeat")
+#endif
 #if ENABLED (JERRY_BUILTIN_REGEXP) && ENABLED (JERRY_BUILTIN_STRING) \
 || ENABLED (JERRY_ES2015_BUILTIN_SYMBOL)
 LIT_MAGIC_STRING_DEF (LIT_MAGIC_STRING_SEARCH, "search")

jerry-core/lit/lit-magic-strings.ini

@@ -139,6 +139,7 @@ LIT_MAGIC_STRING_OBJECT = "object"
 LIT_MAGIC_STRING_RANDOM = "random"
 LIT_MAGIC_STRING_REDUCE = "reduce"
 LIT_MAGIC_STRING_REJECT = "reject"
+LIT_MAGIC_STRING_REPEAT = "repeat"
 LIT_MAGIC_STRING_SEARCH = "search"
 LIT_MAGIC_STRING_SOURCE = "source"
 LIT_MAGIC_STRING_SPLICE = "splice"

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);
+}
+