From f78d920327dd738dd91ccb16a9fe78fe59a4908b Mon Sep 17 00:00:00 2001
From: Vladislav Fursov <ghostrussian@gmail.com>
Date: Fri, 16 Mar 2018 06:12:06 +0900
Subject: [PATCH] separate resolver

---
 internal/exec/exec.go                  | 12 ++++++++-
 internal/exec/resolvable/resolvable.go | 48 ++++++++++++++++++++++++++--------
 2 files changed, 48 insertions(+), 12 deletions(-)

diff --git a/internal/exec/exec.go b/internal/exec/exec.go
index f714961..88d44f5 100644
--- a/internal/exec/exec.go
+++ b/internal/exec/exec.go
@@ -40,7 +40,17 @@ func (r *Request) Execute(ctx context.Context, s *resolvable.Schema, op *query.O
 	func() {
 		defer r.handlePanic(ctx)
 		sels := selected.ApplyOperation(&r.Request, s, op)
-		r.execSelections(ctx, sels, nil, s.Resolver, &out, op.Type == query.Mutation)
+
+		var resolver reflect.Value
+			switch op.Type {
+				case query.Query:
+					resolver = s.QueryResolver
+				case query.Mutation:
+				resolver = s.MutationResolver
+				default:
+				panic("unknown query operation")
+				}
+				r.execSelections(ctx, sels, nil, resolver, &out, op.Type == query.Mutation)
 	}()

 	if err := ctx.Err(); err != nil {
diff --git a/internal/exec/resolvable/resolvable.go b/internal/exec/resolvable/resolvable.go
index b7c1d93..970aef6 100644
--- a/internal/exec/resolvable/resolvable.go
+++ b/internal/exec/resolvable/resolvable.go
@@ -5,7 +5,6 @@ import (
 	"fmt"
 	"reflect"
 	"strings"
-
 	"github.com/graph-gophers/graphql-go/internal/common"
 	"github.com/graph-gophers/graphql-go/internal/exec/packer"
 	"github.com/graph-gophers/graphql-go/internal/schema"
@@ -13,9 +12,10 @@ import (

 type Schema struct {
 	schema.Schema
-	Query    Resolvable
-	Mutation Resolvable
-	Resolver reflect.Value
+	Query            Resolvable
+	Mutation         Resolvable
+	QueryResolver    reflect.Value
+	MutationResolver reflect.Value
 }

 type Resolvable interface {
@@ -54,19 +54,44 @@ func (*Object) isResolvable() {}
 func (*List) isResolvable()   {}
 func (*Scalar) isResolvable() {}

+type Queryer interface {
+	Query() interface{}
+}
+
+type Mutationer interface {
+	Mutation() interface{}
+}
+
 func ApplyResolver(s *schema.Schema, resolver interface{}) (*Schema, error) {
 	b := newBuilder(s)

-	var query, mutation Resolvable
+	var (
+		query, mutation                 Resolvable
+		queryResolver, mutationResolver reflect.Value
+	)
+
+	sqr, isSeparateQueryResolver := resolver.(Queryer)
+	if isSeparateQueryResolver {
+		queryResolver = reflect.ValueOf(sqr.Query())
+	} else {
+		queryResolver = reflect.ValueOf(resolver)
+	}
+
+	smr, isSeparateMutationResolver := resolver.(Mutationer)
+	if isSeparateMutationResolver {
+		mutationResolver = reflect.ValueOf(smr.Mutation())
+	} else {
+		mutationResolver = reflect.ValueOf(resolver)
+	}

 	if t, ok := s.EntryPoints["query"]; ok {
-		if err := b.assignExec(&query, t, reflect.TypeOf(resolver)); err != nil {
+		if err := b.assignExec(&query, t, queryResolver.Type()); err != nil {
 			return nil, err
 		}
 	}

 	if t, ok := s.EntryPoints["mutation"]; ok {
-		if err := b.assignExec(&mutation, t, reflect.TypeOf(resolver)); err != nil {
+		if err := b.assignExec(&mutation, t, mutationResolver.Type()); err != nil {
 			return nil, err
 		}
 	}
@@ -76,10 +101,11 @@ func ApplyResolver(s *schema.Schema, resolver interface{}) (*Schema, error) {
 	}

 	return &Schema{
-		Schema:   *s,
-		Resolver: reflect.ValueOf(resolver),
-		Query:    query,
-		Mutation: mutation,
+		Schema:           *s,
+		Query:            query,
+		Mutation:         mutation,
+		QueryResolver:    queryResolver,
+		MutationResolver: mutationResolver,
 	}, nil
 }

--
2.16.2