diff -r 000000000000 -r 6474c204b198 toolkit/modules/tests/xpcshell/test_BinarySearch.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/modules/tests/xpcshell/test_BinarySearch.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,81 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+Components.utils.import("resource://gre/modules/BinarySearch.jsm");
+
+function run_test() {
+  // empty array
+  ok([], 1, false, 0);
+
+  // one-element array
+  ok([2], 2, true, 0);
+  ok([2], 1, false, 0);
+  ok([2], 3, false, 1);
+
+  // two-element array
+  ok([2, 4], 2, true, 0);
+  ok([2, 4], 4, true, 1);
+  ok([2, 4], 1, false, 0);
+  ok([2, 4], 3, false, 1);
+  ok([2, 4], 5, false, 2);
+
+  // three-element array
+  ok([2, 4, 6], 2, true, 0);
+  ok([2, 4, 6], 4, true, 1);
+  ok([2, 4, 6], 6, true, 2);
+  ok([2, 4, 6], 1, false, 0);
+  ok([2, 4, 6], 3, false, 1);
+  ok([2, 4, 6], 5, false, 2);
+  ok([2, 4, 6], 7, false, 3);
+
+  // duplicates
+  ok([2, 2], 2, true, 0);
+  ok([2, 2], 1, false, 0);
+  ok([2, 2], 3, false, 2);
+
+  // duplicates on the left
+  ok([2, 2, 4], 2, true, 1);
+  ok([2, 2, 4], 4, true, 2);
+  ok([2, 2, 4], 1, false, 0);
+  ok([2, 2, 4], 3, false, 2);
+  ok([2, 2, 4], 5, false, 3);
+
+  // duplicates on the right
+  ok([2, 4, 4], 2, true, 0);
+  ok([2, 4, 4], 4, true, 1);
+  ok([2, 4, 4], 1, false, 0);
+  ok([2, 4, 4], 3, false, 1);
+  ok([2, 4, 4], 5, false, 3);
+
+  // duplicates in the middle
+  ok([2, 4, 4, 6], 2, true, 0);
+  ok([2, 4, 4, 6], 4, true, 1);
+  ok([2, 4, 4, 6], 6, true, 3);
+  ok([2, 4, 4, 6], 1, false, 0);
+  ok([2, 4, 4, 6], 3, false, 1);
+  ok([2, 4, 4, 6], 5, false, 3);
+  ok([2, 4, 4, 6], 7, false, 4);
+
+  // duplicates all around
+  ok([2, 2, 4, 4, 6, 6], 2, true, 0);
+  ok([2, 2, 4, 4, 6, 6], 4, true, 2);
+  ok([2, 2, 4, 4, 6, 6], 6, true, 4);
+  ok([2, 2, 4, 4, 6, 6], 1, false, 0);
+  ok([2, 2, 4, 4, 6, 6], 3, false, 2);
+  ok([2, 2, 4, 4, 6, 6], 5, false, 4);
+  ok([2, 2, 4, 4, 6, 6], 7, false, 6);
+}
+
+function ok(array, target, expectedFound, expectedIdx) {
+  let [found, idx] = BinarySearch.search(array, target, cmp);
+  do_check_eq(found, expectedFound);
+  do_check_eq(idx, expectedIdx);
+
+  idx = expectedFound ? expectedIdx : -1;
+  do_check_eq(BinarySearch.indexOf(array, target, cmp), idx);
+  do_check_eq(BinarySearch.insertionIndexOf(array, target, cmp), expectedIdx);
+}
+
+function cmp(num1, num2) {
+  return num1 - num2;
+}