Working with Timeouts

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Tip

By default, UITests waits up to 15 seconds for tests running locally, and one minute for tests running in App Center before throwing the TimeoutException. If you specify a different wait time, that will override the default, and apply to both local & App Center tests.

Sometimes it's necessary to pause test execution to wait for the UI to update during a long running action. UITest provides two APIs to address these concerns:

• IApp.WaitForElement
• IApp.WaitForNoElement

The methods IApp.WaitForElement, and IApp.WaitForNoElement fundamentally work the same: they'll wait for a query to be satisfied and will throw a TimeoutException if it isn't satisfied in the specified time limit.

IApp.WaitForElement is useful to confirm the presence of a view, such as a success message or icon. This sample is an example of IApp.WaitForElement that will wait up to 90 seconds for a view marked with success_message_label to appear:

app.WaitForElement(c=>c.Marked("success_message_label"),
                   "Didn't see the success message.",
                   new TimeSpan(0,0,0,90,0));

It's a good idea to call IApp.WaitForElement before interacting with views. Many of the gesture APIs will fail if the view isn't visible or is still animating. The following snippet is an extension method that verifies the visibility of a view, and then tries to enter text:

public static class UITestHelpers
{
    public static void WaitThenEnterText(this IApp app, Func<AppQuery, AppQuery> lambda, string text)
    {
        app.WaitForElement(lambda);
        app.EnterText(lambda, text);
    }
}

In contrast, the method IApp.WaitForNoElement is useful to pause the test while some view, such as a progress dialog, is still on the screen:

app.WaitForNoElement(c=>c.Class("TextView").Text("Uploading data..."), 
    "Upload is taking too long",
    new TimeSpan(0,0,90,0));

Both WaitForElement and WaitForNoElement have two additional parameters:

• retryFrequency - The time in milliseconds to wait before retrying the failed query call.

Default: 250

• postTimeout - The time in milliseconds to wait after the element has been found.

Default: 150