When reading Scrum Guide, as the official text for scrum, I find out there is no specific solution to provide software testing in scrum. (the only hint is on page15)

I'm a little vague on whether scrum is considered a software development methodology or not? If it is not, then how come some of its practices opposes Extreme Programming? (I know that in scrum guide, the author notes that scrum is a framework not a methodology, but still I'm not pretty clear on that)

And what's more, I'm not sure if there are any other important textbook that I'm missing so far about scrum. I need them to be official or of great deal of public acceptance.