1 files changed, 26 insertions, 0 deletions
diff --git a/devtools/shared/heapsnapshot/tests/xpcshell/test_census_diff_02.js b/devtools/shared/heapsnapshot/tests/xpcshell/test_census_diff_02.js
new file mode 100644
index 0000000000..cefe76abde
--- /dev/null
+++ b/devtools/shared/heapsnapshot/tests/xpcshell/test_census_diff_02.js
@@ -0,0 +1,26 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+"use strict";
+
+// Test diffing census reports of breakdown by "count".
+
+const BREAKDOWN = { by: "count", count: true, bytes: true };
+
+const REPORT1 = {
+  count: 10,
+  bytes: 100,
+};
+
+const REPORT2 = {
+  count: 11,
+  bytes: 110,
+};
+
+const EXPECTED = {
+  count: 1,
+  bytes: 10,
+};
+
+function run_test() {
+  assertDiff(BREAKDOWN, REPORT1, REPORT2, EXPECTED);
+}