firestore: Checking if structure is empty

[vasi1e]

Is your feature request related to a problem? Please describe.

The data model I am trying to write in firestore contains some nested structures. Like this:

type Address struct {
    Country string `firestore:"country"`
    City string `firestore:"city"`
    PostCode int `firestore:"postcode"`
    Street string `firestore:"street"`
}
type User struct {
   Name string `firestore:"name"`
   AddressInfo Address `firestore:"address,omitempty"`
}

For our business logic is alright if the user do not provide address so in this case the Address object is empty(containing only zero-value fields) and I want to omit it. This tag "omitempty" is not working in this case. The result in firestore is like that:

name: Vasil
address:
    country: ""
    city: ""
    postcode: 0
    street: ""

Describe the solution you'd like

I would want if I said that nested structure should be omitted when empty then this data is skipped in the firestore document:

name: Vasil

I figured out this function is responsible for checking if field is empty or not. Adding one addition case for a struct as simple as that fixes my problem:

func isEmptyValue(v reflect.Value) bool {
	switch v.Kind() {
	case reflect.Array, reflect.Map, reflect.Slice, reflect.String:
		return v.Len() == 0
	case reflect.Bool:
		return !v.Bool()
	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
		return v.Int() == 0
	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
		return v.Uint() == 0
	case reflect.Float32, reflect.Float64:
		return v.Float() == 0
	case reflect.Interface, reflect.Ptr:
		return v.IsNil()
	case reflect.Struct:
		{
			for i := 0; i < v.NumField(); i++ {
				if !isEmptyValue(v.Field(i)) {
					return false
				}
			}

			return true
		}
	}
	if v.Type() == typeOfGoTime {
		return v.Interface().(time.Time).IsZero()
	}
	return false
}

Is there specific reason why this is missed in first place? I could not find any information why I cannot say "omitempty" on nested struct?

Describe alternatives you've considered

Changing the nested structure type to be a reference to this object works with "omitempty" but I have to change the code base and introduce a reference when is not needed. Other approach I think of is adding the tag "omitempty" on the fields of the nested structures:

type Address struct {
    Country string `firestore:"country,omitempty"`
    City string `firestore:"city,omitempty"`
    PostCode int `firestore:"postcode,omitempty"`
    Street string `firestore:"street,omitempty"`
}
type User struct {
   Name string `firestore:"name"`
   AddressInfo Address `firestore:"address,omitempty"`
}

Then this result in the firestore document as empty map:

name: Vasil
address