1 files changed, 114 insertions, 0 deletions
diff --git a/dom/heapsnapshot/tests/unit/test_getReportLeaves_01.js b/dom/heapsnapshot/tests/unit/test_getReportLeaves_01.js
new file mode 100644
index 0000000000..4c4298b6ad
--- /dev/null
+++ b/dom/heapsnapshot/tests/unit/test_getReportLeaves_01.js
@@ -0,0 +1,114 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+"use strict";
+
+// Test basic functionality of `CensusUtils.getReportLeaves`.
+
+function run_test() {
+  const BREAKDOWN = {
+    by: "coarseType",
+    objects: {
+      by: "objectClass",
+      then: { by: "count", count: true, bytes: true },
+      other: { by: "count", count: true, bytes: true },
+    },
+    strings: { by: "count", count: true, bytes: true },
+    scripts: {
+      by: "filename",
+      then: {
+        by: "internalType",
+        then: { by: "count", count: true, bytes: true },
+      },
+      noFilename: {
+        by: "internalType",
+        then: { by: "count", count: true, bytes: true },
+      },
+    },
+    other: {
+      by: "internalType",
+      then: { by: "count", count: true, bytes: true },
+    },
+  };
+
+  const REPORT = {
+    objects: {
+      Array: { count: 6, bytes: 60 },
+      Function: { count: 1, bytes: 10 },
+      Object: { count: 1, bytes: 10 },
+      RegExp: { count: 1, bytes: 10 },
+      other: { count: 0, bytes: 0 },
+    },
+    strings: { count: 1, bytes: 10 },
+    scripts: {
+      "foo.js": {
+        JSScript: { count: 1, bytes: 10 },
+        "js::jit::IonScript": { count: 1, bytes: 10 },
+      },
+      noFilename: {
+        JSScript: { count: 1, bytes: 10 },
+        "js::jit::IonScript": { count: 1, bytes: 10 },
+      },
+    },
+    other: {
+      "js::Shape": { count: 7, bytes: 70 },
+      "js::BaseShape": { count: 1, bytes: 10 },
+    },
+  };
+
+  const root = censusReportToCensusTreeNode(BREAKDOWN, REPORT);
+  dumpn("CensusTreeNode tree = " + JSON.stringify(root, null, 4));
+
+  (function assertEveryNodeCanFindItsLeaf(node) {
+    if (node.reportLeafIndex) {
+      const [ leaf ] = CensusUtils.getReportLeaves(new Set([node.reportLeafIndex]),
+                                                   BREAKDOWN,
+                                                   REPORT);
+      ok(leaf, "Should be able to find leaf for a node with a reportLeafIndex = " + node.reportLeafIndex);
+    }
+
+    if (node.children) {
+      for (let child of node.children) {
+        assertEveryNodeCanFindItsLeaf(child);
+      }
+    }
+  }(root));
+
+  // Test finding multiple leaves at a time.
+
+  function find(name, node) {
+    if (node.name === name) {
+      return node;
+    }
+
+    if (node.children) {
+      for (let child of node.children) {
+        const found = find(name, child);
+        if (found) {
+          return found;
+        }
+      }
+    }
+  }
+
+  const arrayNode = find("Array", root);
+  ok(arrayNode);
+  equal(typeof arrayNode.reportLeafIndex, "number");
+
+  const shapeNode = find("js::Shape", root);
+  ok(shapeNode);
+  equal(typeof shapeNode.reportLeafIndex, "number");
+
+  const indices = new Set([arrayNode.reportLeafIndex, shapeNode.reportLeafIndex]);
+  const leaves = CensusUtils.getReportLeaves(indices, BREAKDOWN, REPORT);
+  equal(leaves.length, 2);
+
+  // `getReportLeaves` does not guarantee order of the results, so handle both
+  // cases.
+  ok(leaves.some(l => l === REPORT.objects.Array));
+  ok(leaves.some(l => l === REPORT.other["js::Shape"]));
+
+  // Test that bad indices do not yield results.
+
+  const none = CensusUtils.getReportLeaves(new Set([999999999999]), BREAKDOWN, REPORT);
+  equal(none.length, 0);
+}