Embedding in input/output structs with omitting fields

[pboguslawski]

Is it possible to omit some fields of embedded struct in input and output interactor structs?

Solution with omit like below doesn't hide ID in openapi.json when ItemCreateRequest is used as interactors input type:

type omit *struct{}

type Item struct {
	ID   uint64 `json:"id" required:"true"`
	Name string `json:"name" required:"true"`
}

type ItemCreateRequest struct {
	Item
	ID omit `json:"id,omitempty"`
}

If omiting fields is not possible - any other best practice to avoid repeating same field definition on every struct that uses this field (i.e. in above example we try to inherit Name field definition from Item and avoid to repeat its definition in ItemCreateRequest but we don't want to allow ItemCreateRequest requests to contain ID field).

[vearutop]

Mentioned solution works for marshaling in some conditions, however it is possible to have a value that results in an object for an "omitted" field:

package main

import (
	"encoding/json"
	"fmt"
)

func main() {
	type omit *struct{}

	type Item struct {
		ID   uint64 `json:"id" required:"true"`
		Name string `json:"name" required:"true"`
	}

	type ItemCreateRequest struct {
		Item
		ID omit `json:"id,omitempty"`
	}

	ic := ItemCreateRequest{}
	ic.Item.ID = 123
	ic.Item.Name = "abc"
	ic.ID = &struct{}{}

	j, _ := json.MarshalIndent(ic, "", " ")
	fmt.Println(string(j))
}

{
 "name": "abc",
 "id": {}
}

It means, that static schema of such field would be {"type":"object"}, not absence of field. It would be possible to make special case for such constructs, but it does not feel right due to hackyness of the solution idea.

I personally prefer precise composition with field groups to hiding fields:

type ItemData struct {
	Name string `json:"name" required:"true"`
}

type Item struct {
	ID   uint64 `json:"id" required:"true"`
	ItemData
}

type ItemCreateRequest = ItemData

[pboguslawski]

Thanks for answer.

I personally prefer precise composition with field groups to hiding fields:

This works but was hoping to avoid "quirks" like

item = &Item{
	ID: 1,
	ItemData: ItemData{
        Name: "test"
    }
}

when creating structs with literals.