         @emitDidChangeEvent({
           oldRange: new Range(Point.ZERO, oldExtent),
           newRange: new Range(Point.ZERO, @buffer.getExtent()),
-          oldText: null,
-          newText: null
+          oldText: '',
+          newText: ''
         })
         @emitter.emit 'did-reload'
     this

    @shouldDestroyOnFileDelete = params?.shouldDestroyOnFileDelete ? -> false

    if params?.filePath
      @serializedChanges = params.outstandingChanges
      @setPath(params.filePath)
      @load() if params?.load


    if filePath = @getPath()
      result.filePath = filePath
      result.digestWhenLastPersisted = @buffer.baseTextDigest()
      result.outstandingChanges = @buffer.serializeChanges().toString('base64')
    else
      result.text = @getText()

