Add m-esr52 at 52.6.0

1 files changed, 48 insertions, 0 deletions

diff --git a/js/src/tests/ecma_6/Array/from_this.js b/js/src/tests/ecma_6/Array/from_this.js
new file mode 100644
index 000000000..978c90b87
--- /dev/null
+++ b/js/src/tests/ecma_6/Array/from_this.js
@@ -0,0 +1,48 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/licenses/publicdomain/ */
+
+// The third argument to Array.from is passed as the 'this' value to the
+// mapping function.
+var hits = 0, obj = {};
+function f(x) {
+    assertEq(this, obj);
+    hits++;
+}
+Array.from(["a", "b", "c"], f, obj);
+assertEq(hits, 3);
+
+// Without an argument, undefined is passed...
+hits = 0;
+function gs(x) {
+    "use strict";
+    assertEq(this, undefined);
+    hits++;
+}
+Array.from("def", gs);
+assertEq(hits, 3);
+
+// ...and if the mapping function is non-strict, that means the global is
+// passed.
+var global = this;
+hits = 0;
+function g(x) {
+    assertEq(this, global);
+    hits++;
+}
+Array.from("ghi", g);
+assertEq(hits, 3);
+
+// A primitive value can be passed.
+for (var v of [0, "str", undefined]) {
+    hits = 0;
+    var mapfn = function h(x) {
+        "use strict";
+        assertEq(this, v);
+        hits++;
+    };
+    Array.from("pq", mapfn, v);
+    assertEq(hits, 2);
+}
+
+if (typeof reportCompare === 'function')
+    reportCompare(0, 0);