1 files changed, 77 insertions, 0 deletions
diff --git a/devtools/server/tests/browser/browser_perf-samples-02.js b/devtools/server/tests/browser/browser_perf-samples-02.js
new file mode 100644
index 000000000..c4d51230d
--- /dev/null
+++ b/devtools/server/tests/browser/browser_perf-samples-02.js
@@ -0,0 +1,77 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * Tests if the retrieved profiler data samples always have a (root) node.
+ * If this ever changes, the |ThreadNode.prototype.insert| function in
+ * devtools/client/performance/modules/logic/tree-model.js will have to be changed.
+ */
+
+const WAIT_TIME = 1000; // ms
+
+const { PerformanceFront } = require("devtools/shared/fronts/performance");
+
+add_task(function* () {
+  let browser = yield addTab(MAIN_DOMAIN + "doc_perf.html");
+  let doc = browser.contentDocument;
+
+  initDebuggerServer();
+  let client = new DebuggerClient(DebuggerServer.connectPipe());
+  let form = yield connectDebuggerClient(client);
+  let front = PerformanceFront(client, form);
+  yield front.connect();
+
+  let rec = yield front.startRecording();
+  busyWait(WAIT_TIME); // allow the profiler module to sample some cpu activity
+
+  yield front.stopRecording(rec);
+  let profile = rec.getProfile();
+  let sampleCount = 0;
+
+  for (let thread of profile.threads) {
+    info("Checking thread: " + thread.name);
+
+    for (let sample of thread.samples.data) {
+      sampleCount++;
+
+      let stack = getInflatedStackLocations(thread, sample);
+      if (stack[0] != "(root)") {
+        ok(false, "The sample " + stack.toSource() + " doesn't have a root node.");
+      }
+    }
+  }
+
+  ok(sampleCount > 0,
+    "At least some samples have been iterated over, checking for root nodes.");
+
+  yield front.destroy();
+  yield client.close();
+  gBrowser.removeCurrentTab();
+});
+
+/**
+ * Inflate a particular sample's stack and return an array of strings.
+ */
+function getInflatedStackLocations(thread, sample) {
+  let stackTable = thread.stackTable;
+  let frameTable = thread.frameTable;
+  let stringTable = thread.stringTable;
+  let SAMPLE_STACK_SLOT = thread.samples.schema.stack;
+  let STACK_PREFIX_SLOT = stackTable.schema.prefix;
+  let STACK_FRAME_SLOT = stackTable.schema.frame;
+  let FRAME_LOCATION_SLOT = frameTable.schema.location;
+
+  // Build the stack from the raw data and accumulate the locations in
+  // an array.
+  let stackIndex = sample[SAMPLE_STACK_SLOT];
+  let locations = [];
+  while (stackIndex !== null) {
+    let stackEntry = stackTable.data[stackIndex];
+    let frame = frameTable.data[stackEntry[STACK_FRAME_SLOT]];
+    locations.push(stringTable[frame[FRAME_LOCATION_SLOT]]);
+    stackIndex = stackEntry[STACK_PREFIX_SLOT];
+  }
+
+  // The profiler tree is inverted, so reverse the array.
+  return locations.reverse();
+}