UserDefaults sometimes does not save

Number:rdar://36054294 Date Originated:14-Dec-2017
Status:Open Resolved:
Product:iOS Product Version:11.2
Classification:Data Loss Reproducible:Often

We use UserDefaults to store whether user saw the app onboarding. We see that setting is not persistent sometimes.

Steps to Reproduce:
Download and open this project in Xcode 9.2
or see the attached project.

Expected Results:
UI Test pass all the time

Actual Results:
UI Test fails sometimes (about 1 in 3 times)

iOS 11.2 Xcode 9.2

iPhone X Simulator and Device.


Failed in Xcode 13.1

Failed in Xcode Version 13.1 (13A1030d), on 5th run of tests:

t =    11.12s             Find: Elements matching predicate '"onboarding not seen" IN identifiers'

UserDefaultsBug/DefaultsBugUITests/DefaultsBugUITests.swift:20: error: -[DefaultsBugUITests.DefaultsBugUITests test1FromNotSeenToSeen] : Failed to get matching snapshot: No matches found for Elements matching predicate '"onboarding not seen" IN identifiers' from input {( Button, label: 'onboarding seen' )}

By alec.vance at Nov. 2, 2021, 10:03 p.m. (reply...)

49809943 - Same issue with Xcode 10.2 and iOS 12.2

Filed again as 49809943 as it fails on the latest Xcode 10.2

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