Why would anyone ever...?
While I'm at work or hacking away at home, I spend most of my development time in Vim.
I tend to edit a lot of PHP classes and the associated test files at the same time...but finding the files and manually opening them, sucks.
It takes some mental energy to find the file and open it, which can interrupt your train of thought. I do use the excellent ctrlp.vim plugin, but the codebase I work in contains way too many files, making the autocomplete kind of awkward to use at times.
I've been thinking of mapping some command to open the related file but have heard bad things about it.
Until I came across this: Optimize Your TDD Workflow by Writing Vim Plugins