stylus.js

var assign = require('object-assign')
var path = require('path')
var ensureRequire = require('../ensure-require.js')

module.exports = function (raw, cb, compiler, filePath) {
  ensureRequire('stylus', 'stylus')
  var stylus = require('stylus')

  var opts = assign({
    filename: path.basename(filePath)
  }, compiler.options.stylus || {})

  var dir = path.dirname(filePath)
  var paths = [dir, process.cwd()]
  opts.paths = opts.paths
    ? opts.paths.concat(paths)
    : paths

  // using the renderer API so that we can
  // check deps after compilation
  var renderer = stylus(raw)
  Object.keys(opts).forEach(function (key) {
    renderer.set(key, opts[key])
  })

  renderer.render(function (err, css) {
    if (err) return cb(err)
    renderer.deps().forEach(function (file) {
      compiler.emit('dependency', file)
    })
    cb(null, css)
  })
}