fileEntry.file() not returning a file

[eeerrrttty]

here is my code:

window.resolveLocalFileSystemURL(cameraCallback, (fileEntry) => {
  this.teste1 = fileEntry
  fileEntry.file(function (file) {
    this.teste2 = file
    let reader = new FileReader()
    reader.onloadend = function (e) {
      this.teste3 = this.result
    }
    reader.readAsDataURL(file)
  })
}, (error) => {
  this.teste4 = error
})

Here is my filyEntry:

File Entry { "isFile": true, "isDirectory": false, "name": "1558418616412.jpg", "fullPath": "/Android/data/org.cordova.quasar.app/cache/1558418616412.jpg", "filesystem": "", "nativeURL": "file:///storage/emulated/0/Android/data/org.cordova.quasar.app/cache/1558418616412.jpg" }
what was i expecting?

--> this.teste2 to be a file, but it is not being returned.