docs: function fileSystem(context, file, fileSet, next) {
    var destinationPath
  
    if (!context.output) {
      debug('Ignoring writing to file-system')
      return next()
    }
  
    if (!file.data.unifiedEngineGiven) {
      debug('Ignoring programmatically added file')
      return next()
    }
  
    destinationPath = file.path
  
    if (!destinationPath) {
      debug('Cannot write file without a `destinationPath`')
      return next(new Error('Cannot write file without an output path'))
    }
  
    if (stats(file).fatal) {
      debug('Cannot write file with a fatal error')
      return next()
    }
  
    destinationPath = resolve(context.cwd, destinationPath)
    debug('Writing document to `%s`', destinationPath)
  
    file.stored = true
  
    writeFile(destinationPath, file.toString(), next)
  }