When opening another file in my project using :e path/to/filTAB, vim will auto-complete the filename with all matching files, in alphabetical order. However, my project is full of .coffee, .litcoffee, .js and .map files.
How do I tell vim not to auto-complete the .js and .map files?
Wildmenu is the component, if you want to call it that, responsible for the files you open with :e. You can set ignore rules for it easily in your .vimrc using
set wildignore+=*.filetype
So say you want to ignore your filetypes, it would be:
set wildignore+=*.js,*.map
There's a great overview here. I would recommend you to write a specific config file for only this project, and load it when you're working on said project. In this way, vim will only ignore these files when you want it to, and not always.
