treat encoding.TextMarshaler as String

Author: jekiapp

util.go

@@ -1,6 +1,7 @@
 package graphql
 
 import (
+	"encoding"
 	"fmt"
 	"reflect"
 	"strings"
@@ -40,7 +41,13 @@ func BindFields(obj interface{}) Fields {
 
 		var graphType Output
 		if fieldType.Kind() == reflect.Struct {
-			structFields := BindFields(v.Field(i).Interface())
+			itf := v.Field(i).Interface()
+			if _, ok := itf.(encoding.TextMarshaler); ok {
+				fieldType = reflect.TypeOf("")
+				goto nonStruct
+			}
+
+			structFields := BindFields(itf)
 
 			if tag == "" {
 				fields = appendFields(fields, structFields)
@@ -53,6 +60,7 @@ func BindFields(obj interface{}) Fields {
 			}
 		}
 
+	nonStruct:
 		if tag == "" {
 			continue
 		}
@@ -122,14 +130,22 @@ func extractValue(originTag string, obj interface{}) interface{} {
 
 	for j := 0; j < val.NumField(); j++ {
 		field := val.Type().Field(j)
+		found := originTag == extractTag(field.Tag)
 		if field.Type.Kind() == reflect.Struct {
-			res := extractValue(originTag, val.Field(j).Interface())
+			itf := val.Field(j).Interface()
+
+			if str, ok := itf.(encoding.TextMarshaler); ok && found {
+				byt, _ := str.MarshalText()
+				return string(byt)
+			}
+
+			res := extractValue(originTag, itf)
 			if res != nil {
 				return res
 			}
 		}
 
-		if originTag == extractTag(field.Tag) {
+		if found {
 			return reflect.Indirect(val.Field(j)).Interface()
 		}
 	}

util_test.go

@@ -5,6 +5,7 @@ import (
 	"log"
 	"reflect"
 	"testing"
+	"time"
 
 	"github.com/graphql-go/graphql"
 	"github.com/graphql-go/graphql/testutil"
@@ -19,9 +20,10 @@ type Person struct {
 }
 
 type Human struct {
-	Alive  bool    `json:"alive,omitempty"`
-	Age    int     `json:"age"`
-	Weight float64 `json:"weight"`
+	Alive  bool      `json:"alive,omitempty"`
+	Age    int       `json:"age"`
+	Weight float64   `json:"weight"`
+	DoB    time.Time `json:"dob"`
 }
 
 type Friend struct {
@@ -40,6 +42,7 @@ var personSource = Person{
 		Age:    24,
 		Weight: 70.1,
 		Alive:  true,
+		DoB:    time.Date(2019, 01, 01, 01, 01, 01, 0, time.UTC),
 	},
 	Name: "John Doe",
 	Home: Address{
@@ -82,6 +85,7 @@ func TestBindFields(t *testing.T) {
 		{
 			person{
 				name,
+				dob,
 				home{street,city},
 				friends{name,address},
 				age,