1 files changed, 61 insertions, 0 deletions
diff --git a/devtools/client/performance/test/helpers/wait-utils.js b/devtools/client/performance/test/helpers/wait-utils.js
new file mode 100644
index 000000000..be654b7d8
--- /dev/null
+++ b/devtools/client/performance/test/helpers/wait-utils.js
@@ -0,0 +1,61 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+"use strict";
+
+/* globals dump */
+
+const { CC } = require("chrome");
+const { Task } = require("devtools/shared/task");
+const DevToolsUtils = require("devtools/shared/DevToolsUtils");
+const { once, observeOnce } = require("devtools/client/performance/test/helpers/event-utils");
+
+/**
+ * Blocks the main thread for the specified amount of time.
+ */
+exports.busyWait = function (time) {
+  dump(`Busy waiting for: ${time} milliseconds.\n`);
+  let start = Date.now();
+  /* eslint-disable no-unused-vars */
+  let stack;
+  while (Date.now() - start < time) {
+    stack = CC.stack;
+  }
+  /* eslint-enable no-unused-vars */
+};
+
+/**
+ * Idly waits for the specified amount of time.
+ */
+exports.idleWait = function (time) {
+  dump(`Idly waiting for: ${time} milliseconds.\n`);
+  return DevToolsUtils.waitForTime(time);
+};
+
+/**
+ * Waits until a predicate returns true.
+ */
+exports.waitUntil = function* (predicate, interval = 100, tries = 100) {
+  for (let i = 1; i <= tries; i++) {
+    if (yield Task.spawn(predicate)) {
+      dump(`Predicate returned true after ${i} tries.\n`);
+      return;
+    }
+    yield exports.idleWait(interval);
+  }
+  throw new Error(`Predicate returned false after ${tries} tries, aborting.\n`);
+};
+
+/**
+ * Waits for a `MozAfterPaint` event to be fired on the specified window.
+ */
+exports.waitForMozAfterPaint = function (window) {
+  return once(window, "MozAfterPaint");
+};
+
+/**
+ * Waits for the `browser-delayed-startup-finished` observer notification
+ * to be fired on the specified window.
+ */
+exports.waitForDelayedStartupFinished = function (window) {
+  return observeOnce("browser-delayed-startup-finished", { expectedSubject: window });
+};