I forgot one error string for the Android readFile() method

[lll000111]

Belongs to issue #460

[lll000111]

I looked at how the "error system" is used and will send a new pull request shortly:

Reference in RN:

• Android: https://github.com/facebook/react-native/blob/master/ReactAndroid/src/main/java/com/facebook/react/bridge/PromiseImpl.java
• iOS: https://github.com/facebook/react-native/blob/master/React/Base/RCTBridgeModule.h

The promise reject() method has three arguments:

1. code This is not supposed to be text but something for the machine, like Unix error codes
2. message This is text for human consumption
3. The internal error object

The third parameter is not actually sent to Javascript at this point, at least not for Android (I didn't find out how RCTPromiseRejectBlock treats that 3rd parameter).

Both code and message go directly to the respective properties of the Javascript Error object.

My intention for my next PR is

• To change the 1st parameter to a CODE (same in Android and iOS of course)
• To add code for "interesting errors" - mostly "File not found". Right now this is a) differently handled by iOS and Android implementation and actually also by each filesystem function, b) results in a default error, so that "file not found" cannot actually be determined from the error message because that information is lost.

@wkh237 Writing in your code feels like walking into your house and moving the furniture around, it's really strange. That's why I'd like to ask beforehand, do you agree with the proposed changes?

[wkh237]

@lll000111 , that's great 👍 I think the error message does need lot of improvement. Besides, I really appreciate your help and feedback 😄