docs: function parse(context, file) {
    var message
  
    if (stats(file).fatal) {
      return
    }
  
    if (context.treeIn) {
      debug('Not parsing already parsed document')
  
      try {
        context.tree = json(file.toString())
      } catch (error) {
        message = file.message(
          new Error('Cannot read file as JSON\n' + error.message)
        )
        message.fatal = true
      }
  
      /* Add the preferred extension to ensure the file, when compiled, is
       * correctly recognized. Only add it if there’s a path — not if the
       * file is for example stdin. */
      if (file.path) {
        file.extname = context.extensions[0]
      }
  
      file.contents = ''
  
      return
    }
  
    debug('Parsing `%s`', file.path)
  
    context.tree = context.processor.parse(file)
  
    debug('Parsed document')
  }