[Golang] Return Error in Golang

Bình thường chúng ta có thể return error như sau:

    res, err := indexReq.Do(ctx, eei.elasticEngine.EE)
    if err != nil {
        log.Error(err.Error())
        return err
    }

Next, you’ll adjust the error handling portion. If res.IsError() evaluates to true, instead of logging the error and continuing, you’ll return an error:

if res.IsError() {
    return fmt.Errorf("Error indexing document: %s", res.String())
} else {
    // ... rest of the success logic ...
}