Ask HN: Could you recommend a good book about writing automated software tests?

I very much appreciate the value of writing automated tests for the software, but I don't have much experience beyond elementary unit tests of functions with well-defined inputs and outputs. Real-world software has complex object relationships, multiple side effects, and user interactions. Could someone recommend me a good book or online resources about patterns and strategies for writing more complex automated tests that take into account the complexity of real-world software?