1 files changed, 51 insertions, 0 deletions
diff --git a/devtools/shared/heapsnapshot/tests/xpcshell/test_census-tree-node-10.js b/devtools/shared/heapsnapshot/tests/xpcshell/test_census-tree-node-10.js
new file mode 100644
index 0000000000..ba783f8e47
--- /dev/null
+++ b/devtools/shared/heapsnapshot/tests/xpcshell/test_census-tree-node-10.js
@@ -0,0 +1,51 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+"use strict";
+
+/**
+ * Test when multiple leaves in the census report map to the same node in an
+ * inverted CensusReportTree.
+ */
+
+function run_test() {
+  const BREAKDOWN = {
+    by: "coarseType",
+    objects: {
+      by: "objectClass",
+      then: { by: "count", count: true, bytes: true },
+    },
+    other: {
+      by: "internalType",
+      then: { by: "count", count: true, bytes: true },
+    },
+    strings: { by: "count", count: true, bytes: true },
+    scripts: { by: "count", count: true, bytes: true },
+    domNode: { by: "count", count: true, bytes: true },
+  };
+
+  const REPORT = {
+    objects: {
+      Array: { count: 1, bytes: 10 },
+    },
+    other: {
+      Array: { count: 1, bytes: 10 },
+    },
+    strings: { count: 0, bytes: 0 },
+    scripts: { count: 0, bytes: 0 },
+    domNode: { count: 0, bytes: 0 },
+  };
+
+  const node = censusReportToCensusTreeNode(BREAKDOWN, REPORT, {
+    invert: true,
+  });
+
+  equal(node.children[0].name, "Array");
+  equal(node.children[0].reportLeafIndex.size, 2);
+  dumpn(
+    `node.children[0].reportLeafIndex = ${[
+      ...node.children[0].reportLeafIndex,
+    ]}`
+  );
+  ok(node.children[0].reportLeafIndex.has(2));
+  ok(node.children[0].reportLeafIndex.has(6));
+}