Xcode 10 - UITests - Reason: image not found

So after 5 days, I managed to solve my own problem.

I solved it by moving my UITests target out of the scope of my main app in Podfile.

From:

target 'App' do
    use_frameworks!

    pods 'Firebase'

    target 'AppUITests' do
        pods 'Testingpod'
    end
end

To:

target 'App' do
    use_frameworks!

    pods 'Firebase'
end

target 'AppUITests' do
    pods 'Testingpod'
end

Has found another solution suggested in Cocoapods issue.

As my project is a framework, so the test does not have a host application.

Changed Podfile

target 'framework' do
    use_ frameworks!
    pods my_dependencies
    target 'framework_tests' do
        inherit! :search_paths
    end
end

To

target 'framework' do
    use_ frameworks!
    pods my_dependencies
    target 'framework_tests'
end

https://github.com/CocoaPods/CocoaPods/issues/8139