1 files changed, 91 insertions, 0 deletions
diff --git a/devtools/client/memory/test/xpcshell/test_dominator_trees_04.js b/devtools/client/memory/test/xpcshell/test_dominator_trees_04.js
new file mode 100644
index 0000000000..d9814590a9
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+++ b/devtools/client/memory/test/xpcshell/test_dominator_trees_04.js
@@ -0,0 +1,91 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test that selecting the dominator tree view while in the middle of taking a
+// snapshot properly kicks off fetching and computing dominator trees.
+
+const {
+  snapshotState: states,
+  dominatorTreeState,
+  viewState,
+} = require("resource://devtools/client/memory/constants.js");
+const {
+  takeSnapshotAndCensus,
+} = require("resource://devtools/client/memory/actions/snapshot.js");
+const {
+  changeView,
+} = require("resource://devtools/client/memory/actions/view.js");
+
+add_task(async function () {
+  const front = new StubbedMemoryFront();
+  const heapWorker = new HeapAnalysesClient();
+  await front.attach();
+
+  for (const intermediateSnapshotState of [
+    states.SAVING,
+    states.READING,
+    states.READ,
+  ]) {
+    dumpn(
+      "Testing switching to the DOMINATOR_TREE view in the middle of the " +
+        `${intermediateSnapshotState} snapshot state`
+    );
+
+    const store = Store();
+    const { getState, dispatch } = store;
+
+    dispatch(takeSnapshotAndCensus(front, heapWorker));
+    await waitUntilSnapshotState(store, [intermediateSnapshotState]);
+
+    dispatch(changeView(viewState.DOMINATOR_TREE));
+    equal(
+      getState().view.state,
+      viewState.DOMINATOR_TREE,
+      "We should now be in the DOMINATOR_TREE view"
+    );
+
+    // Wait for the dominator tree to start being computed.
+    await waitUntilState(
+      store,
+      state => state.snapshots[0] && state.snapshots[0].dominatorTree
+    );
+    equal(
+      getState().snapshots[0].dominatorTree.state,
+      dominatorTreeState.COMPUTING,
+      "The dominator tree started computing"
+    );
+    ok(
+      !getState().snapshots[0].dominatorTree.root,
+      "When the dominator tree is computing, we should not have its root"
+    );
+
+    // Wait for the dominator tree to finish computing and start being fetched.
+    await waitUntilState(
+      store,
+      state =>
+        state.snapshots[0].dominatorTree.state === dominatorTreeState.FETCHING
+    );
+    ok(true, "The dominator tree started fetching");
+    ok(
+      !getState().snapshots[0].dominatorTree.root,
+      "When the dominator tree is fetching, we should not have its root"
+    );
+
+    // Wait for the dominator tree to finish being fetched.
+    await waitUntilState(
+      store,
+      state =>
+        state.snapshots[0].dominatorTree.state === dominatorTreeState.LOADED
+    );
+    ok(true, "The dominator tree was fetched");
+    ok(
+      getState().snapshots[0].dominatorTree.root,
+      "When the dominator tree is loaded, we should have its root"
+    );
+  }
+
+  heapWorker.destroy();
+  await front.detach();
+});