Add basic waitFor implementation.

addon-test-support/@ember/test-helpers/dom/wait-for.js

@@ -0,0 +1,27 @@
+import waitUntil from '../wait-until';
+import { getContext } from '../setup-context';
+import getElement from './-get-element';
+
+/**
+  @method waitFor
+  @param {string|Element} target
+  @param {Object} [options]
+  @param {number} [options.timeout=1000]
+  @param {number} [options.count=1]
+*/
+export function waitFor(selector, { timeout = 1000, count = null } = {}) {
+  let callback;
+  if (count !== null) {
+    callback = () => {
+      let context = getContext();
+      let rootElement = context && context.element;
+      let elements = rootElement.querySelectorAll(selector);
+      if (elements.length === count) {
+        return elements;
+      }
+    };
+  } else {
+    callback = () => getElement(selector);
+  }
+  return waitUntil(callback, { timeout });
+}

addon-test-support/@ember/test-helpers/index.js

@@ -23,3 +23,4 @@ export { default as blur } from './dom/blur';
 export { default as triggerEvent } from './dom/trigger-event';
 export { default as triggerKeyEvent } from './dom/trigger-key-event';
 export { default as fillIn } from './dom/fill-in';
+export { default as waitFor } from './dom/wait-for';