Enums can't be imported

[steebchen]

Expected Behaviour

I want to import existing enums:

models:
  Scope:
    model: github.com/steebchen/api/prisma.Scope

Actual Behavior

Some weird errors appear at runtime, after generating the files:

$ go run .
# github.com/steebchen/api/gqlgen
gqlgen/gqlgen.go:2393:2: not enough arguments to return
gqlgen/gqlgen.go:2393:11: ec.unmarshalInputScope undefined (type *executionContext has no field or method unmarshalInputScope)
gqlgen/gqlgen.go:2397:11: ec._Scope undefined (type *executionContext has no field or method _Scope)

Minimal graphql.schema and models to reproduce

# prisma/prisma.go
type Scope string

const (
	ScopeCompany  Scope = "Company"
	ScopeBranch   Scope = "Branch"
	ScopeEmployee Scope = "Employee"
	ScopeCustomer Scope = "Customer"
)

gqlgen@v0.8.1

[steebchen]

The error appears because I (or my other code generator) didn't implement the following functions on the enum:

func (e Scope) IsValid() bool {
	switch e {
	case ScopeCompany, ScopeBranch, ScopeEmployee, ScopeCustomer:
		return true
	}
	return false
}

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

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

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

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

Maybe the error message could be improved for clarification.

[steebchen]

Would it be maybe useful to just generate those functions if they don't exist on an enum yet? Not sure if that makes sense for everybody, but in my case I just have generated enums from Prisma, but it obviously only generates the enum and not all method gqlgen requires.