Several people (see e.g. issues #23839, #23870, #24030) noticed that the testing chapter of the book used a module called "tests" to hold unit tests but the style guidelines state that unit tests should live in a module named "test". I tried to rename all unit test modules in rust-lang/rust from "tests" to "test" but this does not work in every case, as some crates publicly export a module named "test" or use libtest (see the PR here).
Alex Crichton suggested gathering more opinions about "what the convention should be here, if any", so I followed his advice and opened this post here for discussion.
TL;DR: Should there be a convention for the naming of unit test (sub-)modules and, if yes, what should the name be (test or tests or ...)?