从函数和调用者到终端的Golang错误处理

Question

I want to ask about best practise of error handling, Lets assume I've the following function that read file parse it, which could return two types of errors , when the file not found and the unmarshal failed

func Parse(source string) (bma.Bma, error) {
    file, err := ioutil.ReadFile(source + "bma.yaml")
    m := bma.Bma{}
    if err != nil {
        logs.Error("Not able to read the bma file")
        return m, err
    }
    err = yaml.Unmarshal([]byte(file), &m)
    if err != nil {
        logs.Error("Not able to unmarshal the bma file ")
        return m, err
    }
    return m, err
}

Now If I call to this function and there is error I printing also this error, the Program is CLI program so I think there is too much error will be printed if case of issue, Is It OK, or there is better approach ?

bma ,err := Parse("path")
    if err != nil {
        logs.Error("Error while parsing ")
        return m, err
    }

Answer 1

I think what you are asking is more about when to print errors not when handle or not the errors. In my case I like printing all logs that I can if I think they will be useful for me in future.

In your case maybe the message logs.Error("Error while parsing ") is too verbose because you are not showing any details there.

Other approach that you can consider is returning your custom error to the top level functions instead of in the deeper ones and only display the log message there. In the case of the example should be something like this:

func main() {
    bma, err := Parse("path")
    if err != nil {
        log.Println(err)
        return
    }
}

func Parse(source string) (bma.Bma, error) {
    file, err := ioutil.ReadFile(source + "bma.yaml")
    m := bma.Bma{}
    if err != nil {
        return m, fmt.Errorf("Not able to read the bma file: %s", err.Error())
    }
    err = yaml.Unmarshal([]byte(file), &m)
    if err != nil {
        return m, fmt.Errorf("Not able to unmarshal the bma file: %s", err.Error())
    }
    return m, err
}