Implement spread operator for function call arguments (#3329)

JerryScript-DCO-1.0-Signed-off-by: Robert Fancsik frobert@inf.u-szeged.hu

tests/jerry/es2015/argument-spread.js

@@ -0,0 +1,100 @@
+// 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.
+
+// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Spread_syntax
+
+function mustThrow(str) {
+  try {
+    eval(str);
+    assert(false);
+  } catch (e) {
+    assert(e instanceof TypeError);
+  }
+}
+
+function assertArrayEqual(actual, expected) {
+  assert(actual.length === expected.length);
+
+  for (var i = 0; i < actual.length; i++) {
+    assert(actual[i] === expected[i]);
+  }
+}
+
+// Spread syntax
+function sum(x, y, z) {
+  return x + y + z;
+}
+
+const numbers = [1, 2, 3];
+
+assert(sum(...numbers) === 6);
+
+// Replace apply()
+function myFunction (v, w, x, y, z) {
+  return v + w + x + y + z;
+}
+var args = [0, 1];
+
+assert(myFunction (-1, ...args, 2, ...[3]) == 5);
+
+// Apply for new
+var dateFields = [1970, 0, 1];
+var d = new Date(...dateFields);
+
+assert(d.toString().substring(0, 24) === "Thu Jan 01 1970 00:00:00");
+
+function applyAndNew(constructor, args) {
+   function partial () {
+      return constructor.apply (this, args);
+   };
+   if (typeof constructor.prototype === "object") {
+      partial.prototype = Object.create(constructor.prototype);
+   }
+   return partial;
+}
+
+function myConstructor () {
+   assertArrayEqual(arguments, myArguments);
+   this.prop1 = "val1";
+   this.prop2 = "val2";
+};
+
+var myArguments = ["hi", "how", "are", "you", "mr", null];
+var myConstructorWithArguments = applyAndNew(myConstructor, myArguments);
+
+var obj = new myConstructorWithArguments;
+assert(Object.keys(obj).length === 2);
+assert(obj.prop1 === "val1");
+assert(obj.prop2 === "val2");
+
+// Test spread prop call
+var o = { f(a,b,c) { return a + b + c },
+          g(a,b) { throw new TypeError ("5") }
+        };
+
+assert (o.f(...["a", "b", "c"]) === "abc");
+
+mustThrow ("o.g (...[1,2])")
+
+// Test spread super call
+class MyArray extends Array {
+  constructor(...args) {
+    super(...args);
+  }
+}
+
+var array = new MyArray(1, 2, 3);
+assertArrayEqual(array, [1,2,3]);
+assert(array instanceof MyArray);
+assert(array instanceof Array);