feat: Better error handling for 'native' plugins.

[TaaBooThree]

Feature Request

Describe the Feature Request

Hey guys, we are running into issues when handling plugins on native devices.

For example the Geolocation.getCurrentLocation() function returns a different error object on web than it does on native devices.

The error object on this particular function on native devices currently only holds a message property. Without any documentation, it is hard to see what kind of errors it may throw and to write code around handling these errors.

The error object on web is the GeolocationPositionError. It's a lot easier to write different methods around the types of errors it can throw.

The same goes for other plugins like the Camera plugin.

Platform Support Requested

• Android
• iOS
• Electron
• Web

Describe Preferred Solution

The preferred solution would be a single error object that we can use to handle the error in the same way across platforms. It would also help to have documentation of the errors that certain functions throw. I currently have to search for the error types in the @capacitor/core package.

[jcesarmobile]

javascript errors can have a code number and a few other properties, so this could be done

Adding the needs discussion label

[diachedelic]

It is difficult to categorise Filesystem errors across different platforms, for example:

try {
  await Filesystem.stat({ directory, path })
} catch (err) {
  const androidFileNotFound = err.message === 'File does not exist'
  const iosFileNotFound = err.message.includes('was not found')

  if (androidFileNotFound || iosFileNotFound) {
    return null
  } else {
    // unknown error
    throw err
  }
}

Perhaps well documented err.code properties could be implemented?

[Gorshtak]

Any updates on this issue? @jcesarmobile
IMO this will be a great improvement.

[TaaBooThree]

It is difficult to categorise Filesystem errors across different platforms, for example:

try {
  await Filesystem.stat({ directory, path })
} catch (err) {
  const androidFileNotFound = err.message === 'File does not exist'
  const iosFileNotFound = err.message.includes('was not found')

  if (androidFileNotFound || iosFileNotFound) {
    return null
  } else {
    // unknown error
    throw err
  }
}

Perhaps well documented err.code properties could be implemented?

I'd like to see a general error for a file not found scenario as well as the actual platform specific error. Some people might want to handle platform specific errors after all.

One thing that would really help is just documentation around the errors object it throws and the possible messages you can get. I have no idea what kind of error scenarios I can expect and how to handle them properly without going through the source code.

[thoro23]

Reviving this feture request because this is absolutely needed. For example I want to delete a file. If the file does not exist its ok because I wanted to delete it anyway. But I want an display an error message if I do not have the permissions to delete it.

try {
  await Filesystem.deleteFile({ directory, path });
catch (err) {
  // file not found
  if (err.code === 1) {
    return;
  }

  alert(err.message);
}

[robingenz]

It is difficult to categorise Filesystem errors across different platforms, for example:

try {
  await Filesystem.stat({ directory, path })
} catch (err) {
  const androidFileNotFound = err.message === 'File does not exist'
  const iosFileNotFound = err.message.includes('was not found')

  if (androidFileNotFound || iosFileNotFound) {
    return null
  } else {
    // unknown error
    throw err
  }
}

Perhaps well documented err.code properties could be implemented?

Even this solution unfortunately only works if the device is set to English (please correct me if I am wrong).
A customer has set his device to German and the plugin throws the following error if a file does not exist when deleting: Die Datei "image.png" konnte nicht geöffnet werden, da die Datei nicht existiert.
This makes it almost impossible to deal with specific errors at the moment.

[diachedelic]

I just assume that every error is a File Not Found. But this is a little bit dangerous because it could result in an existing file being inadvertently overwritten.

[aaronclawrence]

FWIW I think that all plugins produce the same error object, which is basically

export interface CapacitorPluginError {
    message: string;
    code: string; // usually not specified
    data: object; // additional data, usually not specified
}

So it's possible for plugins to supply a code that would presumably be easier to use, but most don't do so, they only supply the message. In most plugins it's a hard-coded English string,

[harveyea30]

Ensure consistent error structure returned through all of our cap plugins.