Visual tests are more general, and are more akin to putting up barriers on either side of a bowling lane so the bowling ball stays within it's lane (with room to move about still). For example when using Angular, you write 'Page Objects' that have methods such as .getTitle(), .clickListItem(3) and so on, and can then write assertions to make sure the UI changes as expected by inspecting properties [1].

I usually find I build a general page object first ('this text is somewhere on the page'), then write the UI, then make the test more specific if I can after (but it's an art, as too specific and you risk creating too many false negatives when you make UI changes).

(Also as you are interacting with the UI, these would be known as integration tests.)

[1] https://semaphoreci.com/community/tutorials/using-page-objec...

I don't think you can unit test GUIs, since by their nature all tests end up being integration tests. It's easy if you assign non-css (i.e. use a data-* attribute for identification instead of id or class since you want to keep those variable for stylesheet refactors) identifiers and just hard code the assumptions into the tests, like "when x is clicked y should be visible", or "when I enter 'foo' into the text field, the preview label should contain 'foo'". Ideally your assumptions about GUI functionality shouldn't change much throughout the lifetime of the project, and if you use static identifiers your tests should hold up during extensive refactoring.

That is my point of view, since my focus are mostly native GUIs.

Which is why it is my main question on TDD talks, that always use some library or CLI app as example.

To a certain degree you can unit test GUIs with tools like Ranorex or Selenium. The question is how much setup you need to get the GUI on the screen with the right data.

That isn't unit testing though, it's integration or e2e testing.

You can, but usually with lots of effort and cannot test UX and design requirements anyway, which is why I tend to make this question about full TDD based processes.

We use Ranorex for this: https://www.ranorex.com/

Interesting, thanks for the link.

I think so. I don't know how to unit test GUIs either.

I saw an enjoyable talk recently about snapshot testing. I don't know too much about testing generally but it seems like it could be relevant: https://facebook.github.io/jest/docs/en/snapshot-testing.htm... is the general idea but it doesn't have to be confined to jest/react

Edit: Slides from the talk I saw: http://slides.com/bahmutov/snapshot-testing