1 files changed, 87 insertions, 0 deletions
diff --git a/js/src/tests/test262/built-ins/Array/prototype/flatMap/array-like-objects.js b/js/src/tests/test262/built-ins/Array/prototype/flatMap/array-like-objects.js
new file mode 100644
index 0000000000..6c5fa28717
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+++ b/js/src/tests/test262/built-ins/Array/prototype/flatMap/array-like-objects.js
@@ -0,0 +1,87 @@
+// Copyright (C) 2018 Shilpi Jain and Michael Ficarra. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-array.prototype.flatMap
+description: >
+  array-like objects can be flattened
+info: |
+  Array.prototype.flatMap ( mapperFunction [ , thisArg ] )
+
+  1. Let O be ? ToObject(this value).
+  2. Let sourceLen be ? ToLength(? Get(O, "length")).
+  ...
+  5. Let A be ? ArraySpeciesCreate(O, 0).
+  ...
+
+  ArraySpeciesCreate ( originalArray, length )
+
+  3. Let isArray be ? IsArray(originalArray).
+  4. If isArray is false, return ? ArrayCreate(length).
+
+  FlattenIntoArray(target, source, sourceLen, start, depth [ , mapperFunction, thisArg ])
+
+  1. Let targetIndex be start.
+  2. Let sourceIndex be 0.
+  3. Repeat, while sourceIndex < sourceLen
+    a. Let P be ! ToString(sourceIndex).
+    b. Let exists be ? HasProperty(source, P).
+    c. If exists is true, then
+      ...
+    ** Skip if property does not exist **
+includes: [compareArray.js]
+features: [Array.prototype.flatMap]
+---*/
+
+function fn(e) {
+  return [39, e * 2]; // returns an array to observe it being flattened after
+}
+
+var a;
+var actual;
+
+a = {
+  length: 3,
+  0: 1,
+  // property 1 will be fully skipped
+  2: 21,
+  get 3() { throw 'it should not get this property'; }
+};
+actual = [].flatMap.call(a, fn);
+assert.compareArray(actual, [39, 2, 39, 42], 'The value of actual is expected to be [39, 2, 39, 42]');
+assert.sameValue(Object.getPrototypeOf(actual), Array.prototype, 'Object.getPrototypeOf([].flatMap.call(a, fn)") returns Array.prototype');
+
+a = {
+  length: undefined,
+  get 0() { throw 'it should not get this property'; },
+};
+actual = [].flatMap.call(a, fn);
+assert.compareArray(actual, [], 'The value of actual is expected to be []');
+assert.sameValue(Object.getPrototypeOf(actual), Array.prototype, 'Object.getPrototypeOf([].flatMap.call(a, fn)") returns Array.prototype');
+
+var called = false;
+a = {
+  get length() {
+    if (!called) {
+      called = true;
+      return 2;
+    } else {
+      throw 'is should get the length only once';
+    }
+  },
+  0: 21,
+  1: 19.5,
+  get 2() { throw 'it should not get this property'; },
+};
+actual = [].flatMap.call(a, fn);
+assert.compareArray(actual, [39, 42, 39, 39], 'The value of actual is expected to be [39, 42, 39, 39]');
+assert.sameValue(Object.getPrototypeOf(actual), Array.prototype, 'Object.getPrototypeOf([].flatMap.call(a, fn)") returns Array.prototype');
+
+a = {
+  length: 10001,
+  [10000]: 7,
+};
+actual = [].flatMap.call(a, fn);
+assert.compareArray(actual, [39, 14], 'The value of actual is expected to be [39, 14]');
+assert.sameValue(Object.getPrototypeOf(actual), Array.prototype, 'Object.getPrototypeOf([].flatMap.call(a, fn)") returns Array.prototype');
+
+reportCompare(0, 0);