1 files changed, 141 insertions, 0 deletions
diff --git a/devtools/shared/heapsnapshot/tests/xpcshell/test_DominatorTreeNode_attachShortestPaths_01.js b/devtools/shared/heapsnapshot/tests/xpcshell/test_DominatorTreeNode_attachShortestPaths_01.js
new file mode 100644
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+++ b/devtools/shared/heapsnapshot/tests/xpcshell/test_DominatorTreeNode_attachShortestPaths_01.js
@@ -0,0 +1,141 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+"use strict";
+
+// Test that the DominatorTreeNode.attachShortestPaths function can correctly
+// attach the deduplicated shortest retaining paths for each node it is given.
+
+const startNodeId = 9999;
+const maxNumPaths = 2;
+
+// Mock data mapping node id to shortest paths to that node id.
+const shortestPaths = new Map([
+  [
+    1000,
+    [
+      [pathEntry(1100, "a"), pathEntry(1200, "b")],
+      [pathEntry(1100, "c"), pathEntry(1300, "d")],
+    ],
+  ],
+  [2000, [[pathEntry(2100, "e"), pathEntry(2200, "f"), pathEntry(2300, "g")]]],
+  [
+    3000,
+    [
+      [pathEntry(3100, "h")],
+      [pathEntry(3100, "i")],
+      [pathEntry(3100, "j")],
+      [pathEntry(3200, "k")],
+      [pathEntry(3300, "l")],
+      [pathEntry(3400, "m")],
+    ],
+  ],
+]);
+
+const actual = [
+  makeTestDominatorTreeNode({ nodeId: 1000 }),
+  makeTestDominatorTreeNode({ nodeId: 2000 }),
+  makeTestDominatorTreeNode({ nodeId: 3000 }),
+];
+
+const expected = [
+  makeTestDominatorTreeNode({
+    nodeId: 1000,
+    shortestPaths: {
+      nodes: [
+        { id: 1000, label: ["SomeType-1000"] },
+        { id: 1100, label: ["SomeType-1100"] },
+        { id: 1200, label: ["SomeType-1200"] },
+        { id: 1300, label: ["SomeType-1300"] },
+      ],
+      edges: [
+        { from: 1100, to: 1200, name: "a" },
+        { from: 1100, to: 1300, name: "c" },
+        { from: 1200, to: 1000, name: "b" },
+        { from: 1300, to: 1000, name: "d" },
+      ],
+    },
+  }),
+
+  makeTestDominatorTreeNode({
+    nodeId: 2000,
+    shortestPaths: {
+      nodes: [
+        { id: 2000, label: ["SomeType-2000"] },
+        { id: 2100, label: ["SomeType-2100"] },
+        { id: 2200, label: ["SomeType-2200"] },
+        { id: 2300, label: ["SomeType-2300"] },
+      ],
+      edges: [
+        { from: 2100, to: 2200, name: "e" },
+        { from: 2200, to: 2300, name: "f" },
+        { from: 2300, to: 2000, name: "g" },
+      ],
+    },
+  }),
+
+  makeTestDominatorTreeNode({
+    nodeId: 3000,
+    shortestPaths: {
+      nodes: [
+        { id: 3000, label: ["SomeType-3000"] },
+        { id: 3100, label: ["SomeType-3100"] },
+        { id: 3200, label: ["SomeType-3200"] },
+        { id: 3300, label: ["SomeType-3300"] },
+        { id: 3400, label: ["SomeType-3400"] },
+      ],
+      edges: [
+        { from: 3100, to: 3000, name: "h" },
+        { from: 3100, to: 3000, name: "i" },
+        { from: 3100, to: 3000, name: "j" },
+        { from: 3200, to: 3000, name: "k" },
+        { from: 3300, to: 3000, name: "l" },
+        { from: 3400, to: 3000, name: "m" },
+      ],
+    },
+  }),
+];
+
+const breakdown = {
+  by: "internalType",
+  then: { by: "count", count: true, bytes: true },
+};
+
+const mockSnapshot = {
+  computeShortestPaths: (start, nodeIds, max) => {
+    equal(start, startNodeId);
+    equal(max, maxNumPaths);
+
+    return new Map(
+      nodeIds.map(nodeId => {
+        const paths = shortestPaths.get(nodeId);
+        ok(paths, "Expected computeShortestPaths call for node id = " + nodeId);
+        return [nodeId, paths];
+      })
+    );
+  },
+
+  describeNode: (bd, nodeId) => {
+    equal(bd, breakdown);
+    return {
+      ["SomeType-" + nodeId]: {
+        count: 1,
+        bytes: 10,
+      },
+    };
+  },
+};
+
+function run_test() {
+  DominatorTreeNode.attachShortestPaths(
+    mockSnapshot,
+    breakdown,
+    startNodeId,
+    actual,
+    maxNumPaths
+  );
+
+  dumpn("Expected = " + JSON.stringify(expected, null, 2));
+  dumpn("Actual = " + JSON.stringify(actual, null, 2));
+
+  assertStructurallyEquivalent(expected, actual);
+}