rqlite creator here. I'm not developing libraries, I'm developing an entire RDBMS. In my experience -- and this is broader than rqlite -- integration and end-t

rqlite creator here. I'm not developing libraries, I'm developing an entire RDBMS. In my experience -- and this is broader than rqlite -- integration and end-to-end tests seem like they are great - at the start. But as you rely more and more on them they become costly to maintain and really hard to debug. A single test failure (often due to a flaky, timing-sensitive issue) means wading through layers and layers of code to identify the issue. Overly relying on integration and end-to-end testing (note I said over-reliance, there is absolutely a need for them) becomes exponentially more costly over time (measured in development velocity and time to debug) as the test suite grows. If you find you're having difficulty identifying a place for them it may that you're not decomposing your software properly in the first place. All this is probably manageable if you're a solo developer, but when a team is building the software it can become really painful. For more details see the talk I gave to CMU[1] on my testing strategy. [1]https://youtu.be/JLlIAWjvHxM?t=2067 https://youtu.be/JLlIAWjvHxM?t=2067