[j_w]

Why can you not run specific tests from neovim?

If you really wanted to you could add some trigger on save for a file that would re-run tests for said file. Maybe a plugin or key bind could run a specific test which you choose in buffer.

[giaour]

I'm sure there is a way to use a step debugger with a specific unit test in Neovim or whatever, but it's one of the things heavyweight IDEs do with no setup or configuration.