I have often thought that GUIs, including browsers, are hard to test because the monstrous frameworks that they are make no accommodation for testing, so... of

I have often thought that GUIs, including browsers, are hard to test because the monstrous frameworks that they are make no accommodation for testing, so... of course they're hard to test. Not only are you writing a test harness around your own code, you also must rather laboriously and unreliably harness up their code too, and from the "outside" not designed to be used the way you're trying to use it to boot. Now, I don't necessarily fault GUI designers for not thinking about how to expose testability easily to their users, they're big enough projects as it is, enough to choke even a major multibillion dollar corporation, but it doesn't mean I'm any less frustrated while using them. Game engines strike me as much the same thing for similar reasons. Yes, it would be really hard to not only have Unity as it stands today but also have all the requisite changes it would take to make it really testable, but without that you're really going uphill. It's an uphill battle at best and a sheer cliff face at worst trying to test these things. And of course when that's the case, every step your local engine programmer takes only takes you farther in the direction of being untestable because why would they bother structuring their code to be testable when the framework it is embedded in is untestable? I have no solution. Only the observation that both of these systems (and also the browser, if you think of "the browser" as something other than a really funky large GUI) have problems from the very, very beginning, and until the foundation gets its act together w.r.t. testability it is always going to be a major uphill battle with anything built on that foundation. (I'm not so idealistic that I imagine any world where a AAA game has 100% automated test coverage or anything, but even in my own limited experience in game dev and less limited, but still limited, experience in GUI programming, both places where I tried to leverage my extensive years of writing automated tests even in hostile legacy codebases, I found myself not merely stymied a bit, not merely inconvenienced a bit, but comprehensively blocked at every turn. An simple example: A table cell in a table widget that had a .SetColor, but no way whatsoever to fetch the color. Meaning my code to highlight rows matching a certain criterion could not be tested; in this case, for that reason alone. What a ^#&*$@'ing stupid reason to be unable to test some non-trivial code, at least from my perspective gained over years of writing a lot of other test code... and discovering plenty of errors in code of similar complexity in places where I could test it.)