Support wrapped type for []query.SelectedField as resolver argument

Author: dvic

graphql.go

@@ -53,8 +53,8 @@ func ParseSchema(schemaString string, resolver interface{}, opts ...SchemaOpt) (
 func MustParseSchema(schemaString string, resolver interface{}, opts ...SchemaOpt) *Schema {
 	s, err := ParseSchema(schemaString, resolver, opts...)
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "parse schema error: %+v\n\n", err)
-		panic(err)
+		fmt.Fprintf(os.Stderr, "%+v\n\n", err)
+		panic("parse schema failed")
 	}
 	return s
 }

graphql_test.go

@@ -18,6 +18,8 @@ func (r *helloWorldResolver1) Hello() string {
 	return "Hello world!"
 }
 
+type mySelectedFields []query.SelectedField
+
 type selectedFieldsResolver struct {
 	assert func(fields []query.SelectedField)
 }
@@ -38,6 +40,11 @@ func (r *selectedFieldsResolver) Do3(_ context.Context, args struct{ Name string
 	return &helloWorldResolver1{}
 }
 
+func (r *selectedFieldsResolver) Do4(fields mySelectedFields) *helloWorldResolver1 {
+	r.assert(fields)
+	return &helloWorldResolver1{}
+}
+
 type helloWorldResolver2 struct{}
 
 func (r *helloWorldResolver2) Hello(ctx context.Context) (string, error) {
@@ -231,6 +238,38 @@ func TestSelectedFields(t *testing.T) {
 				}
 			`,
 		},
+		{
+			Schema: graphql.MustParseSchema(`
+				schema {
+					query: Query
+				}
+				type Hello {
+					hello: String!
+				}
+				type Query {
+					do4: Hello!
+				}
+			`, &selectedFieldsResolver{
+				assert: func(got []query.SelectedField) {
+					want := []query.SelectedField{
+						{Name: "hello"},
+					}
+					if !reflect.DeepEqual(want, got) {
+						t.Errorf("want %#v, got %#v", want, got)
+					}
+				},
+			}),
+			Query: `
+				{
+					do4 { hello }
+				}
+			`,
+			ExpectedResult: `
+				{
+					"do4": { "hello": "Hello world!" }
+				}
+			`,
+		},
 	})
 }
 

internal/exec/resolvable/resolvable.go

@@ -254,7 +254,7 @@ func (b *execBuilder) makeObjectExec(typeName string, fields schema.FieldList, p
 }
 
 var contextType = reflect.TypeOf((*context.Context)(nil)).Elem()
-var selectedType = reflect.TypeOf([]pubquery.SelectedField(nil))
+var selectedType = reflect.TypeOf(pubquery.SelectedField{})
 var errorType = reflect.TypeOf((*error)(nil)).Elem()
 
 func (b *execBuilder) makeFieldExec(typeName string, f *schema.Field, m reflect.Method, methodIndex int, methodHasReceiver bool) (*Field, error) {
@@ -284,7 +284,7 @@ func (b *execBuilder) makeFieldExec(typeName string, f *schema.Field, m reflect.
 		in = in[1:]
 	}
 
-	hasSelected := len(in) > 0 && in[0] == selectedType
+	hasSelected := len(in) > 0 && isSelectedFieldType(in[0])
 	if hasSelected {
 		in = in[1:]
 	}
@@ -320,6 +320,10 @@ func (b *execBuilder) makeFieldExec(typeName string, f *schema.Field, m reflect.
 	return fe, nil
 }
 
+func isSelectedFieldType(in reflect.Type) bool {
+	return in.Kind() == reflect.Slice && in.Elem() == selectedType
+}
+
 func findMethod(t reflect.Type, name string) int {
 	for i := 0; i < t.NumMethod(); i++ {
 		if strings.EqualFold(stripUnderscore(name), stripUnderscore(t.Method(i).Name)) {