Right now, the simpleforce lib generally logs errors to stdout.

        if err != nil {
		log.Println(logPrefix, "json decode failed,", err)
		return nil
	}

There are a few issues with this

1. The client does not have visibility to the error and therefore cannot appropriately handle a failure
2. Many production services will have a specific log format which this likely won't follow (ex. JSON logs to be picked up by a parser to ship to an ELK stack) If the log line doesn't follow the format, they will be ignored and the failure will be invisible

I'd like to propose a change to have errors returned the the client so that the client and properly handle failures and log appropriately. ex:

        if err != nil {
		return JsonDecodeErr
	}