Use pointers to structs inside slices

codegen/config/binder.go

@@ -383,7 +383,11 @@ func (b *Binder) TypeReference(schemaType *ast.Type, bindTarget types.Type) (ret
 
 func (b *Binder) CopyModifiersFromAst(t *ast.Type, base types.Type) types.Type {
 	if t.Elem != nil {
-		return types.NewSlice(b.CopyModifiersFromAst(t.Elem, base))
+		child := b.CopyModifiersFromAst(t.Elem, base)
+		if _, isStruct := child.Underlying().(*types.Struct); isStruct {
+			child = types.NewPointer(child)
+		}
+		return types.NewSlice(child)
 	}
 
 	var isInterface bool

codegen/testserver/middleware_test.go

@@ -23,8 +23,8 @@ func TestMiddleware(t *testing.T) {
 		return &User{ID: 1}, nil
 	}
 
-	resolvers.UserResolver.Friends = func(ctx context.Context, obj *User) (users []User, e error) {
-		return []User{{ID: 1}}, nil
+	resolvers.UserResolver.Friends = func(ctx context.Context, obj *User) (users []*User, e error) {
+		return []*User{{ID: 1}}, nil
 	}
 
 	areMethods := []bool{}
@@ -57,10 +57,10 @@ func TestMiddleware(t *testing.T) {
 	}
 
 	called := false
-	resolvers.UserResolver.Friends = func(ctx context.Context, obj *User) ([]User, error) {
+	resolvers.UserResolver.Friends = func(ctx context.Context, obj *User) ([]*User, error) {
 		assert.Equal(t, []int{1, 2, 1, 2}, ctx.Value("path"))
 		called = true
-		return []User{}, nil
+		return []*User{}, nil
 	}
 
 	err := c.Post(`query { user(id: 1) { id, friends { id } } }`, &resp)

codegen/testserver/resolver.go

@@ -215,6 +215,6 @@ func (r *subscriptionResolver) InitPayload(ctx context.Context) (<-chan string,
 
 type userResolver struct{ *Resolver }
 
-func (r *userResolver) Friends(ctx context.Context, obj *User) ([]User, error) {
+func (r *userResolver) Friends(ctx context.Context, obj *User) ([]*User, error) {
 	panic("not implemented")
 }

codegen/testserver/tracer_test.go

@@ -64,7 +64,7 @@ func TestTracer(t *testing.T) {
 		}
 
 		called := false
-		resolvers.UserResolver.Friends = func(ctx context.Context, obj *User) ([]User, error) {
+		resolvers.UserResolver.Friends = func(ctx context.Context, obj *User) ([]*User, error) {
 			assert.Equal(t, []string{
 				"op:p:start:1", "op:p:start:2",
 				"op:v:start:1", "op:v:start:2",
@@ -76,7 +76,7 @@ func TestTracer(t *testing.T) {
 				"field'b:e:start:1:[user friends]", "field'b:e:start:2:[user friends]",
 			}, ctx.Value("tracer"))
 			called = true
-			return []User{}, nil
+			return []*User{}, nil
 		}
 
 		err := c.Post(`query { user(id: 1) { id, friends { id } } }`, &resp)
@@ -175,9 +175,9 @@ func TestTracer(t *testing.T) {
 		}
 
 		called := false
-		resolvers.UserResolver.Friends = func(ctx context.Context, obj *User) ([]User, error) {
+		resolvers.UserResolver.Friends = func(ctx context.Context, obj *User) ([]*User, error) {
 			called = true
-			return []User{}, nil
+			return []*User{}, nil
 		}
 
 		err := c.Post(`query { user(id: 1) { id, friends { id } } }`, &resp)

example/config/resolver.go

@@ -10,7 +10,7 @@ import (
 func New() Config {
 	c := Config{
 		Resolvers: &Resolver{
-			todos: []Todo{
+			todos: []*Todo{
 				{DatabaseID: 1, Description: "A todo not to forget", Done: false},
 				{DatabaseID: 2, Description: "This is the most important", Done: false},
 				{DatabaseID: 3, Description: "Please do this or else", Done: false},
@@ -22,7 +22,7 @@ func New() Config {
 }
 
 type Resolver struct {
-	todos  []Todo
+	todos  []*Todo
 	nextID int
 }
 
@@ -42,19 +42,19 @@ func (r *mutationResolver) CreateTodo(ctx context.Context, input NewTodo) (*Todo
 	newID := r.nextID
 	r.nextID++
 
-	newTodo := Todo{
+	newTodo := &Todo{
 		DatabaseID:  newID,
 		Description: input.Text,
 	}
 
 	r.todos = append(r.todos, newTodo)
 
-	return &newTodo, nil
+	return newTodo, nil
 }
 
 type queryResolver struct{ *Resolver }
 
-func (r *queryResolver) Todos(ctx context.Context) ([]Todo, error) {
+func (r *queryResolver) Todos(ctx context.Context) ([]*Todo, error) {
 	return r.todos, nil
 }