Handle errors for Cloud Storage on Flutter

Sometimes when you're building an app, things don't go as planned and an error occurs!

When in doubt, catch the exception thrown by the function and see what the error message has to say.

final storageRef = FirebaseStorage.instance.ref().child("files/uid");
try {
  final listResult = await storageRef.listAll();
} on FirebaseException catch (e) {
  // Caught an exception from Firebase.
  print("Failed with error '${e.code}': ${e.message}");
}

Handle Error Messages

There are a number of reasons why errors may occur, including the file not existing, the user not having permission to access the desired file, or the user cancelling the file upload.

To properly diagnose the issue and handle the error, here is a full list of all the errors our client will raise, and how they occurred.

Code Description
storage/unknown An unknown error occurred.
storage/object-not-found No object exists at the desired reference.
storage/bucket-not-found No bucket is configured for Cloud Storage
storage/project-not-found No project is configured for Cloud Storage
storage/quota-exceeded Quota on your Cloud Storage bucket has been exceeded. If you're on the no-cost tier, upgrade to a paid plan. If you're on a paid plan, reach out to Firebase support.
storage/unauthenticated User is unauthenticated, please authenticate and try again.
storage/unauthorized User is not authorized to perform the desired action, check your security rules to ensure they are correct.
storage/retry-limit-exceeded The maximum time limit on an operation (upload, download, delete, etc.) has been excceded. Try uploading again.
storage/invalid-checksum File on the client does not match the checksum of the file received by the server. Try uploading again.
storage/canceled User canceled the operation.
storage/invalid-event-name Invalid event name provided. Must be one of [running, progress, pause]
storage/invalid-url Invalid URL provided to refFromURL(). Must be of the form: gs://bucket/object or https://firebasestorage.googleapis.com/v0/b/bucket/o/object?token=<TOKEN>
storage/invalid-argument The argument passed to put() must be File, Blob, or UInt8 Array. The argument passed to putString() must be a raw, Base64, or Base64URL string.
storage/no-default-bucket No bucket has been set in your config's storageBucket property.
storage/cannot-slice-blob Commonly occurs when the local file has changed (deleted, saved again, etc.). Try uploading again after verifying that the file hasn't changed.
storage/server-file-wrong-size File on the client does not match the size of the file received by the server. Try uploading again.