Xcuitest - 我怎样才能等到图像完成加载

Question

I'm running my UiTests on app that uses images/videos from the camera roll/Google photos/Etc..

All the images/videos are in CollectionView and each asset is in a specific cell.

When the app opens the "footage screen" it contains 15 assets at the same time and I'm trying to create a function that waits until all of the images finish to load.

Why do I need it: I have tests that select images/videos and sometimes the Xctest could select the first one because not all of the assets finish loading.

Note: I don't have any indication that tells me "all the assets finish to load".

Any suggestions?

Answer 1

• You should inspect your app.debugDescription before and after loading. Find anything that you can asynchronously verify.

• If necessary, add accessibility identifiers into app code, that are different before/after loading. You should also add some accessibility labels to help VoiceOver and VoiceControl users to interact with your app.

• You can use SUITCase for screenshot testing and awaits. https://github.com/devexperts/suitcase/

• You can add some EarlGrey 2 asserts. This testing framework is a little bit more flexible and automatically await async operations. The good thing is you can use it alongside existing XCTest tests.

• Finally, you can just sleep(5) :D

Answer 2

There is expectation method in XCTest framework to test asynchronous work.

expectation

Use this method to create XCTestExpectation instances that can be fulfilled when asynchronous tasks in your tests complete.

You can create a function for the use of existence prediction like below:

// create a function to wait for prediction
func waitNotExistance(for element: XCUIElement, timeout: Double = 5) {
    let notExists = NSPredicate(format: "exists != 1")
    let elementShown = expectation(for: notExists, evaluatedWith: element)
    wait(for: [elementShown], timeout: timeout, enforceOrder: false)
}

Assume that you set accessibilityIdentifier " loading " as initial value and " loaded " after completion. You can wait until non-existence for them.

Usage :

// your loading cell
let ladingElement = app.collectionViews.element(boundBy: 0).cells.matching(identifier: "loading").element

// wait until timeout reached 
waitNotExistance(for: ladingElement)

// assert here what you expect..

Answer 3

The second suggestion resolve the problem,

I've added an accessibility identifiers to the cells that containing the images 1: When the image is still loading "selectFootageCellImageEmpty" 2. When the image finishes loading "selectFootageCellImageLoaded" And now I wait until there is no "selectFootageCellImageEmpty" in the screen for example:

        let endOfLoop = Date().addingTimeInterval(TimeInterval(10))
        while app.collectionViews.element(boundBy: 2).cells.matching(identifier: "selectFootageCellImageEmpty").element.exists {
        sleep(1)
        print("Waiting for all images to finish loading")
        if Date() > endOfLoop {
            break
        }
    }

• I could add an XCTAssert instead of the "break" line but I don't need it at the moment.