old_contents: 'use babel'
  
  export const compiler = false
  export const minifier = true
  
  let uglify = null
  
  export function process(contents, _, {config, state}) {
    if (uglify === null) {
      uglify = require('uglify-js')
    }
    const options = Object.assign({
      fromString: true,
      outSourceMap: 'processed.map'
    }, config.uglify)
    const processed = uglify.minify(contents, options)
    state.sourceMap = processed.map
    return processed.code.slice(0, -34)
  }
  
new_contents: 'use babel'
  
  import {dirname} from 'path'
  
  export const compiler = false
  export const minifier = true
  
  let uglify = null
  
  export function process(contents, {fileName, absolutePath}, {config, state}) {
    if (uglify === null) {
      uglify = require('uglify-js')
    }
    const options = Object.assign({
      fromString: true,
      outSourceMap: 'something'
    }, config.uglify)
    const processed = uglify.minify(contents, options)
    state.sourceMap = JSON.parse(processed.map)
    state.sourceMap = {
      version: state.sourceMap.version,
      sources: [fileName],
      file: fileName,
      mappings: state.sourceMap.mappings,
      names: state.sourceMap.names,
      sourceRoot: dirname(absolutePath),
      sourcesContent: [contents]
    }
    return processed.code.slice(0, -30)
  }
  
subject: Implement source map support