1 files changed, 51 insertions, 0 deletions
diff --git a/js/src/tests/ecma_6/Array/from_basics.js b/js/src/tests/ecma_6/Array/from_basics.js
new file mode 100644
index 000000000..623207a41
--- /dev/null
+++ b/js/src/tests/ecma_6/Array/from_basics.js
@@ -0,0 +1,51 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/licenses/publicdomain/ */
+
+// Array.from copies arrays.
+var src = [1, 2, 3], copy = Array.from(src);
+assertEq(copy === src, false);
+assertEq(Array.isArray(copy), true);
+assertDeepEq(copy, src);
+
+// Non-element properties are not copied.
+var a = [0, 1];
+a.name = "lisa";
+assertDeepEq(Array.from(a), [0, 1]);
+
+// It's a shallow copy.
+src = [[0], [1]];
+copy = Array.from(src);
+assertEq(copy[0], src[0]);
+assertEq(copy[1], src[1]);
+
+// Array.from can copy non-iterable objects, if they're array-like.
+src = {0: "zero", 1: "one", length: 2};
+copy = Array.from(src);
+assertEq(Array.isArray(copy), true);
+assertDeepEq(copy, ["zero", "one"]);
+
+// Properties past the .length are not copied.
+src = {0: "zero", 1: "one", 2: "two", 9: "nine", name: "lisa", length: 2};
+assertDeepEq(Array.from(src), ["zero", "one"]);
+
+// If an object has neither an @@iterator method nor .length,
+// then it's treated as zero-length.
+assertDeepEq(Array.from({}), []);
+
+// Source object property order doesn't matter.
+src = {length: 2, 1: "last", 0: "first"};
+assertDeepEq(Array.from(src), ["first", "last"]);
+
+// Array.from does not preserve holes.
+assertDeepEq(Array.from(Array(3)), [undefined, undefined, undefined]);
+assertDeepEq(Array.from([, , 2, 3]), [undefined, undefined, 2, 3]);
+assertDeepEq(Array.from([0, , , ,]), [0, undefined, undefined, undefined]);
+
+// Even on non-iterable objects.
+assertDeepEq(Array.from({length: 4}), [undefined, undefined, undefined, undefined]);
+
+// Array.from should coerce negative lengths to zero.
+assertDeepEq(Array.from({length: -1}), []);
+
+if (typeof reportCompare === 'function')
+    reportCompare(0, 0);