Change ErrorNum to Enum

[AlistairB99124]

No description provided.

[DiscoPYF]

Are you referring to the property inside the ApiErrorResponse class? While having an enum for the ArangoDB error codes is nice, this also means one more thing to maintain and keep in sync between versions of ArangoDB. Are we willing to do that? 🤔

[DiscoPYF]

I looked at the Java driver and they seem fine with using an int as the type: https://github.com/arangodb/arangodb-java-driver/blob/master/src/main/java/com/arangodb/entity/ErrorEntity.java

[AlistairB99124]

The benefit for me is that using an enum is more descriptive and there would be less need to lookup what the error means

[rossmills99]

OK let's discuss this on Monday. I don't expect the error numbers to ever change, partly because there's no reason to change them. The only issue I see is new error numbers might be introduced in new versions of ArangoDB.

[rossmills99]

So we've decided to close this issue for now and continue using int to represent the error number. If a new version of ArangoDB introduces new error codes, there is no way to represent them in the client until you update it, if we use enum. Using int at least allows us to represent new error numbers that might be introduced with no change.