Fix crash when using `UIWindow` in `assertSnapshot`

[zenangst]

prepareView in View.swift will now check if the current snapshot target is a UIWindow. If that condition is true, then it will return early and use the window as its dispose value. It will make the assumption that the window has a rootViewController set and use that as it's viewController.

This avoids unbalanced calls to appearance transitions during test teardown which will throw exceptions and crash the test.

[zenangst]

@stephencelis mind taking a look a this? 😎

[stephencelis]

Hey @zenangst! Thanks for taking the time to submit this and sorry if things are taking a bit longer to take a look at.

Given the early out does this mean that the traits and sizing will not be applied to the window?

[zenangst]

Yeah traits and sizing should be left out. Maybe that is a false assumption on my part but if you give it the window then everything down the line should already be handled in your test. What do you think?

[zenangst]

@stephencelis I pushed another commit to include the traits if the root view controller of the window could be resolved. Is that an okay assignment seeing that rootViewController is optional in UIWindow and it is non-optional on the add method. Or should we fail early here and just throw an exception if the root view controller cannot be resolved?

[zenangst]

ping @stephencelis 😎

[zenangst]

Any headway here? Something that needs changing before it can be merged? 🌞

[zenangst]

@stephencelis

[dmitrysimkin]

Please merge, I also encounter this issue

[zenangst]

I merged this with main now 😎

[okankocyigit]

@stephencelis will you merge this one, we are also having the same issue and it has been more then one year since @zenangst requested this PR?

That would be great if you merge, we don't want to continue with forked one, thanks :)

[krzysztofpawski]

We have those changes on our fork for a while now and it works perfectly. Maybe this could be somehow merged? 🐱🙏 @stephencelis ? :)