Gqlgen: Enum with int values

[karthikraobr]

Is it possible to generate enum with int values rather than string values? Something that looks like the below code?

type Op int32

const (
    Op_NULL   Op = 0
    Op_CREATE Op = 1
    Op_MODIFY Op = 2
    Op_DELETE Op = 3
)

var Op_name = map[int32]string{
    0: "NULL",
    1: "CREATE",
    2: "MODIFY",
    3: "DELETE",
}
var Op_value = map[string]int32{
    "NULL":   0,
    "CREATE": 1,
    "MODIFY": 2,
    "DELETE": 3,
} 

Minimal graphql.schema and models to reproduce

enum Op {
        Op_NULL 
    Op_CREATE
    Op_MODIFY
    Op_DELETE
}

Generates

type Op string

const (
    OpOpNull   Op = "Op_NULL"
    OpOpCreate Op = "Op_CREATE"
    OpOpModify Op = "Op_MODIFY"
    OpOpDelete Op = "Op_DELETE"
)

func (e Op) IsValid() bool {
    switch e {
    case OpOpNull, OpOpCreate, OpOpModify, OpOpDelete:
        return true
    }
    return false
}

func (e Op) String() string {
    return string(e)
}

func (e *Op) UnmarshalGQL(v interface{}) error {
    str, ok := v.(string)
    if !ok {
        return fmt.Errorf("enums must be strings")
    }

    *e = Op(str)
    if !e.IsValid() {
        return fmt.Errorf("%s is not a valid Op", str)
    }
    return nil
}

func (e Op) MarshalGQL(w io.Writer) {
    fmt.Fprint(w, strconv.Quote(e.String()))
}

Is there any way to generate int values rather than string values for enums? Perhaps a custom resolver?

[JulienBreux]

Good idea! Like grpc generator ;)

[lwc]

This is probably a good use-case for ENUM_VALUE directives - they have something similar in the GraphQL Compatibility Acceptance Tests.

[lwc]

The other option would be custom mapping - you'd be opting out of model generation, but you could map the enum however you like

[mia0x75]

This is probably a good use-case for ENUM_VALUE directives - they have something similar in the GraphQL Compatibility Acceptance Tests.

@lwc How the directive function looks like?

func EnumInt(ctx context.Context, obj interface{}, next graphql.Resolver, value int) (res interface{}, err error) {
    return value, nil // Just return the value?
}

[longfellowone]

Another vote for numeric enums

type ItemStatus int

const (
    Waiting ItemStatus = iota
    Filled
    BackOrdered
    OrderExceeded
    NotOrdered
)

func (s ItemStatus) String() string {
    switch s {
    case Waiting:
        return "Waiting"
    case Filled:
        return "Filled"
    case BackOrdered:
        return "Back Ordered"
    case OrderExceeded:
        return "Order Exceeded"
    case NotOrdered:
        return "Not Ordered"
    default:
        return fmt.Sprintf("%d", int(s))
    }
}

[steebchen]

It would also be great for a simple permission system, so I could check for user.Role >= Employee to allow access to "employees" and all roles above (e.g. admin)

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[karthikraobr]

@vektah Could you please reopen this issue. Thanks

[oshalygin]

@karthikraobr thanks!
This would be very helpful!

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[steebchen]

No stale

[tonyhb]

Right now I'm using this fork of enumer which adds GQLGen support via this PR. It may help people :)