Run pyflakes/jslint automatically in Vim

As maybe you can tell from the infrequency of updates to this blog, I (and the others with whom I'm working) have been churning out a huge amount of code recently, split roughly evenly between Python and JavaScript. One nice thing I got used to during the month I tried to switch from Vim to TextMate was a plugin that ran pyflakes every time I saved a Python file. After I gave up and went back to Vim, I missed that check. Luckily, other, more vimscript-savvy coders had the same idea. Here's how to set up both pyflakes and jslint to run on save.

1. pyflakes. I installed this excellent plugin:
   
   

   $ git clone git://github.com/kevinw/pyflakes-vim.git
   $ mkdir -p ~/.vim/ftplugin/python
   $ cp pyflakes-vim/pyflakes.vim ~/.vim/ftplugin/python

   I also followed his advice and installed his fork of pyflakes, which is incredibly faster than the original version:
   
   

   $ git clone git://github.com/kevinw/pyflakes.git
   $ cd pyflakes
   $ sudo python setup.py install

   
   This plugin actually highlights errors inline as you edit, and puts details in the status bar when you're over a line with an error:
   
   
   
   
   
2. jslint. This plugin is easier to install, though it doesn't have the same on-the-fly checking as the pyflakes plugin.
   
   

   $ git clone git://github.com/hallettj/jslint.vim.git
   $ cd jslint.vim
   $ rake install

   
   Then you can run jslint easily from within Vim:
   
   

   :JSLint

   
   That'll give you a nice quickfix window with all your extant problems.
   
   
   
   
   To have it run on save, simply add to ~/.vimrc:
   
   

   autocmd BufWritePost *.js JSLint

   
   Finally, you can also pass options into jslint by putting them in ~/.jslintrc. For example, because I'm working with a few global namespaces/functions defined in other files, I have:
   
   

   /* global Ext, Zenoss, _t */

   
   That way, you can eliminate any noise and get right to the trailing commas.
   
   I may try my hand at hacking the jslint plugin to do the same inline highlighting as the pyflakes plugin.
   

Anyway, there it is. Definitely helps keep the silly typos down.