I really like that there is now a button in RStudio that you can check tests only for a specific file. I'm sure it used work with one of the preview versions, but now it doesn't anymore.
When I pressed the button I see the following error:
==> Testing R file using 'testthat'
Error in path.expand(path) : invalid 'path' argument
Calls: <Anonymous> ... rprojroot_find_root -> get_start_path -> normalizePath -> path.expand
Execution halted
Exited with status 1.
RStudio version:
Build 1104 (2e0f7658)
Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) QtWebEngine/5.10.1 Chrome/61.0.3163.140 Safari/537.36