I think we need some general exception interface that to make cross platform ErrorMessage for Promise reject

[Matrixbirds]

Introduction

I'm working on react native module exception design. I need some tool class to help me design more general cross platform error exception which used to be javascript layer. I don't want to write different handlers for different platform so that i looked the react native FileReaderModule.

In FileReaderModule, we could see react native team use Promise interface to resolve and reject the result. but there is two different error codes here.

# in objc
NSString *const RCTErrorUnspecified = @"EUNSPECIFIED";

# in java
private static final String ERROR_INVALID_BLOB = "ERROR_INVALID_BLOB";

I think probably we need design more cross platform Promise interface or add a new ExceptionModule for react native Promise interface.

Proposals of ExceptionModule

interface RCTErrorModule {
  code: string,
  description: string
};
promise.reject(new RCTErrorModule(code: "errorCode", description: "description"));