How to check for three different struct keys in the golang map?

I have a below method where I create three different struct object to check as a key in my name map. If I can find the value, I return back otherwise I return empty string and status.

func (r *clientRepo) GetName(id int64, name map[models.LocaleInfo]string, clientId int32, code models.Locale) (string, bool) {
	localeInfo := models.LocaleInfo{
		Locale:  code,
		GroupID: int(clientId),
	}

	localeInfoUS := models.LocaleInfo{
		Locale:  "US",
		GroupID: int(clientId),
	}

	localeInfoGB := models.LocaleInfo{
		Locale:  "GB",
		GroupID: int(clientId),
	}

	value := ""
	ok := false
	if value, ok = name[localeInfo]; !ok {
		if value, ok = name[localeInfoUS]; !ok {
			if value, ok := name[localeInfoGB]; !ok {
				errs.Newf("Unable to find locale for ProductId: %d", id)
				return value, ok
			}
		}
	}
	
	return value, ok
}

Is there any way to improve above code where I don't have to keep separate line for each US and GB locale info. My if block also looks very nested and I think that can be improved a lot as well.

The special "comma-ok" form can only be used in an assignment, so you can't make it more compact.

What you may do is write a utility function which uses a for loop to check any number of keys.

Using Go 1.18 generics, you can make it work with any map type:

func findKeys[K comparable, V any](m map[K]V, keys ...K) (v V, ok bool) {
	for _, key := range keys {
		if v, ok = m[key]; ok {
			return
		}
	}
	return
}

Testing it:

m := map[int]string{
	1: "one",
	2: "two",
	3: "three",
	4: "four",
}

fmt.Println(findKeys(m, 5, 6, 4))
fmt.Println(findKeys(m, 1, 2, 6))
fmt.Println(findKeys(m, 6, 8))

Which outputs (try it on the Go Playground):

four true
one true
 false

Note: if you're using a Go prior to Go 1.18, simply use a non-generic version of findKeys():

func findKeys(m map[models.LocaleInfo]string, keys ...models.LocaleInfo) (v string, ok bool) {
    for _, key := range keys {
        if v, ok = m[key]; ok {
            return
        }
    }
    return
}

You could use this findKeys() like this:

value, ok := findKeys(name, localeInfo, localeInfoUS, localeInfoGB)
if !ok {
	errs.Newf("Unable to find locale for ProductId: %d", id)
}
return value, ok

Also note that if you're using a non-generic version, since it will be restricted to your map type anyway, you can move more code into it: it can handle the key creation, so you only have to pass the string locale values (and the clientId):

func findKeys(names map[models.LocaleInfo]string, clientId int, locales ...string) (v string, ok bool) {
	key := models.LocaleInfo{GroupID: clientId}
	for _, locale := range locales {
		key.Locale = locale
		if v, ok = names[key]; ok {
			return
		}
	}
	return
}

Calling it is like:

value, ok := findKeys(names, int(clientId), code, "US", "GB")

See related question: https://stackoverflow.com/questions/41978101/check-if-key-exists-in-multiple-maps-in-one-condition/41978277#41978277