add lint-friendly small interfaces option for resolvers

codegen/object.go

@@ -50,13 +50,44 @@ func (o *Object) Implementors() string {
 	return "[]string{" + satisfiedBy + "}"
 }
 
+func (o *Object) HasResolvers() bool {
+	for _, f := range o.Fields {
+		if f.IsResolver() {
+			return true
+		}
+	}
+	return false
+}
+
 func (f *Field) IsResolver() bool {
 	return f.GoMethodName == "" && f.GoVarName == ""
 }
 
 func (f *Field) IsConcurrent() bool {
 	return f.IsResolver() && !f.Object.DisableConcurrency
 }
+func (f *Field) ShortInvocation() string {
+	if !f.IsResolver() {
+		return ""
+	}
+	shortName := strings.ToUpper(f.GQLName[:1]) + f.GQLName[1:]
+	res := fmt.Sprintf("%s().%s(ctx", f.Object.GQLType, shortName)
+	if !f.Object.Root {
+		res += fmt.Sprintf(", obj")
+	}
+	for _, arg := range f.Args {
+		res += fmt.Sprintf(", %s", arg.GoVarName)
+	}
+	res += ")"
+	return res
+}
+func (f *Field) ShortResolverDeclaration() string {
+	if !f.IsResolver() {
+		return ""
+	}
+	decl := strings.TrimPrefix(f.ResolverDeclaration(), f.Object.GQLType+"_")
+	return strings.ToUpper(decl[:1]) + decl[1:]
+}
 
 func (f *Field) ResolverDeclaration() string {
 	if !f.IsResolver() {

codegen/templates/generated.gotpl

@@ -8,10 +8,16 @@ import (
 {{ end }}
 )
 
+// MakeExecutableSchema creates an ExecutableSchema from the Resolvers interface.
 func MakeExecutableSchema(resolvers Resolvers) graphql.ExecutableSchema {
 	return &executableSchema{resolvers: resolvers}
 }
 
+// NewExecutableSchema creates an ExecutableSchema from the ResolverRoot interface.
+func NewExecutableSchema(resolvers ResolverRoot) graphql.ExecutableSchema {
+	return MakeExecutableSchema(shortMapper{r: resolvers})
+}
+
 type Resolvers interface {
 {{- range $object := .Objects -}}
 	{{ range $field := $object.Fields -}}
@@ -20,6 +26,38 @@ type Resolvers interface {
 {{- end }}
 }
 
+type ResolverRoot interface {
+{{- range $object := .Objects -}}
+	{{ if $object.HasResolvers -}}
+		{{$object.GQLType}}() {{$object.GQLType}}Resolver
+	{{ end }}
+{{- end }}
+}
+
+{{- range $object := .Objects -}}
+	{{ if $object.HasResolvers }}
+		type {{$object.GQLType}}Resolver interface {
+		{{ range $field := $object.Fields -}}
+			{{ $field.ShortResolverDeclaration }}
+		{{ end }}
+		}
+	{{- end }}
+{{- end }}
+
+type shortMapper struct {
+	r ResolverRoot
+}
+
+{{- range $object := .Objects -}}
+	{{ range $field := $object.Fields -}}
+		{{- if $field.IsResolver }}
+			func (s shortMapper) {{ $field.ResolverDeclaration }} {
+				return s.r.{{$field.ShortInvocation}}
+			}
+		{{- end }}
+	{{ end }}
+{{- end }}
+
 type executableSchema struct {
 	resolvers      Resolvers
 }