Yes. To do that, I fuzz like crazy, and every path becomes a test, even if it means a lot of manual work checking each one. That alone exercises tons of error

Yes. To do that, I fuzz like crazy, and every path becomes a test, even if it means a lot of manual work checking each one. That alone exercises tons of error paths. To cover 99% of the rest, I use SQLite's error injection [1] on all tests. Just doing error injection on allocation gets you 90% of the way there. [1]: https://sqlite.org/testing.html#anomaly_testing https://sqlite.org/testing.html#anomaly_testing