Looks like this is an actively maintained and valued library (380 stars): https://github.com/parroty/excoveralls
I see no disclaimer however about the risc of coverage objectives inhibiting quality improvement + coverage having no correlation with code quality.
Dave Thomas in programming elixir:
Test Coverage Some people believe that if there are any lines of application code that haven’t been exercised by a test, the code is incomplete. (I’m not one of them.) These folks use test coverage tools to check for untested code. Here we’ll use excoveralls to see where to add tests for the Issues app.
related: BDD / TDD criticized
Also worth a read for all good lib maintainers on github providing
extensive unit tests: (which could make others to follow their
example - add extensive unit tests to their code) :
I found that not only were unit tests extremely brittle due to their coupling to volatile implementation details, but they also formed the wider base of the regression pyramid. In other words, they were a pain to maintain [..] I set forward a simple guideline for the developers: Always give preference to integration/system tests over unit tests. I didn't ban unit tests—that would be stupid—but reserved those for special cases. [..] Give up unit tests and get results We are now three years into our product and have been getting tremendous value from our automation approach. Try it yourself. Not only will giving up on unit tests not hurt development experience or product quality, but it will also allow your team to focus efforts on the system and integration level tests that provide you with the biggest bang for the buck.