[es6] Spread in array literals

test/mjsunit/harmony/spread-array.js

+// Copyright 2015 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --harmony-spread-arrays --allow-natives-syntax
+
+(function TestBasics() {
+  var a = [1, 2];
+  var b = [...a];
+  assertArrayEquals([1, 2], b)
+
+  assertArrayEquals(['a', 'b', 'c', 'd', 'e', 'f'],
+                    ['a', ...'bc', 'd', ...'ef'])
+})();
+
+
+var log = [];
+
+function* gen(n) {
+  log.push(n, 1);
+  yield 1;
+  log.push(n, 2);
+  yield 2;
+  log.push(n, 3);
+  yield 3;
+  log.push(n, 'done');
+}
+
+function id(v) {
+  log.push(v);
+  return v;
+}
+
+
+(function TestGenerator() {
+  assertArrayEquals([1, 2, 3], [...gen('a')]);
+  assertArrayEquals(['x', 1, 2, 3, 'y', 1, 2, 3, 'z'],
+                    ['x', ...gen('a'), 'y', ...gen('b'), 'z']);
+})();
+
+
+(function TestOrderOfExecution() {
+  log = [];
+  assertArrayEquals(['x', 1, 2, 3, 'y', 1, 2, 3, 'z'],
+                    [id('x'), ...gen('a'), id('y'), ...gen('b'), id('z')]);
+  assertArrayEquals([
+    'x', 'a', 1, 'a', 2, 'a', 3, 'a', 'done',
+    'y', 'b', 1, 'b', 2, 'b', 3, 'b', 'done',
+    'z'
+  ], log);
+})();
+
+
+(function TestNotIterable() {
+  var a;
+  assertThrows(function() {
+    a = [...42];
+  }, TypeError);
+  assertSame(undefined, a);
+
+
+})();
+
+
+(function TestInvalidIterator() {
+  var iter = {
+    [Symbol.iterator]: 42
+  };
+  var a;
+  assertThrows(function() {
+    a = [...iter];
+  }, TypeError);
+  assertSame(undefined, a);
+})();
+
+
+(function TestIteratorNotAnObject() {
+  var iter = {
+    [Symbol.iterator]() {
+      return 42;
+    }
+  };
+  var a;
+  assertThrows(function() {
+    a = [...iter];
+  }, TypeError);
+  assertSame(undefined, a);
+})();
+
+
+(function TestIteratorNoNext() {
+  var iter = {
+    [Symbol.iterator]() {
+      return {};
+    }
+  };
+  var a;
+  assertThrows(function() {
+    a = [...iter];
+  }, TypeError);
+  assertSame(undefined, a);
+})();
+
+
+(function TestIteratorResultDoneThrows() {
+  function MyError() {}
+  var iter = {
+    [Symbol.iterator]() {
+      return {
+        next() {
+          return {
+            get done() {
+              throw new MyError();
+            }
+          }
+        }
+      };
+    }
+  };
+  var a;
+  assertThrows(function() {
+    a = [...iter];
+  }, MyError);
+  assertSame(undefined, a);
+})();
+
+
+(function TestIteratorResultValueThrows() {
+  function MyError() {}
+  var iter = {
+    [Symbol.iterator]() {
+      return {
+        next() {
+          return {
+            done: false,
+            get value() {
+              throw new MyError();
+            }
+          }
+        }
+      };
+    }
+  };
+  var a;
+  assertThrows(function() {
+    a = [...iter];
+  }, MyError);
+  assertSame(undefined, a);
+})();
+
+
+(function TestOptimize() {
+  function f() {
+    return [...'abc'];
+  }
+  assertArrayEquals(['a', 'b', 'c'], f());
+  %OptimizeFunctionOnNextCall(f);
+  assertArrayEquals(['a', 'b', 'c'], f());
+})();
+
+
+(function TestDeoptimize() {
+  var iter = {
+    [Symbol.iterator]() {
+      var i = 0;
+      return {
+        next() {
+          $DeoptimizeFunction(f);
+          return {value: ++i, done: i === 3};
+        }
+      };
+    }
+  };
+  function f() {
+    return [0, ...iter];
+  }
+
+  assertArrayEquals([0, 1, 2], f());
+});