Wait until object is not visible on the screen using Swift and XCTest

Question

I'm looking for help writing a method which waits until the specified element is not present on a page anymore. I am developing with Swift 2.2 and XCTest. As you can see, I'm a new here and new to programming. Your help will be greatly appreciated.

Answer 1

You will have to setup predicate for the condition you want to test:

let doesNotExistPredicate = NSPredicate(format: "exists == FALSE")

Then create an expectation for your predicate and UI element in your test case:

self.expectationForPredicate(doesNotExistPredicate, evaluatedWithObject: element, handler: nil)

Then wait for your expectation (specifying a timeout after which the test will fail if the expectation is not met, here I use 5 seconds):

self.waitForExpectationsWithTimeout(5.0, handler: nil)

Answer 2

I wrote a super simple waitForNonExistence(timeout:) extension function on XCUIElement for this which mirrors the existing XCUIElement.waitForExistence(timeout:) function, as follows:

extension XCUIElement {

    /**
     * Waits the specified amount of time for the element’s `exists` property to become `false`.
     *
     * - Parameter timeout: The amount of time to wait.
     * - Returns: `false` if the timeout expires without the element coming out of existence.
     */
    func waitForNonExistence(timeout: TimeInterval) -> Bool {
    
        let timeStart = Date().timeIntervalSince1970
    
        while (Date().timeIntervalSince1970 <= (timeStart + timeout)) {
            if !exists { return true }
        }
    
        return false
    }
}

Answer 3

You can check the element by XCUIElement.exists for 10 second for each second and then assert the element. See the following for ActivityIndicator:

public func waitActivityIndicator() {
    var numberTry = 0
    var activityIndicatorNotVisible = false
    while numberTry < 10 {
        if activityIdentifier.exists {
            sleep(1)
            numberTry += 1
        } else {
            activityIndicatorNotVisible = true
            break
        }
    }
    
    XCTAssert(activityIndicatorNotVisible, "Activity indicator is still visible")
}

Answer 4

@Charles A has the correct answer. Below is the Swift 5 version of the same.

        let doesNotExistPredicate = NSPredicate(format: "exists == FALSE")
    expectation(for: doesNotExistPredicate, evaluatedWith: element, handler: nil)
    waitForExpectations(timeout: 5.0, handler: nil)