1 files changed, 13 insertions, 0 deletions
diff --git a/dom/heapsnapshot/tests/unit/test_DominatorTree_03.js b/dom/heapsnapshot/tests/unit/test_DominatorTree_03.js
new file mode 100644
index 0000000000..0a14ce53da
--- /dev/null
+++ b/dom/heapsnapshot/tests/unit/test_DominatorTree_03.js
@@ -0,0 +1,13 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Test that we can get the root of dominator trees.
+
+function run_test() {
+  const dominatorTree = saveHeapSnapshotAndComputeDominatorTree();
+  equal(typeof dominatorTree.root, "number", "root should be a number");
+  equal(Math.floor(dominatorTree.root), dominatorTree.root, "root should be an integer");
+  ok(dominatorTree.root >= 0, "root should be positive");
+  ok(dominatorTree.root <= Math.pow(2, 48), "root should be less than or equal to 2^48");
+  do_test_finished();
+}