change field marshaler return process that make it easy to insert oth…

…er processing

codegen/object.go

@@ -220,7 +220,15 @@ func (f *Field) CallArgs() string {
 
 // should be in the template, but its recursive and has a bunch of args
 func (f *Field) WriteJson() string {
-	return f.doWriteJson("res", f.Type.Modifiers, f.ASTType, false, 1)
+	return strings.TrimSpace(
+		tpl(`
+			func () graphql.Marshaler {
+				{{ .next }}
+			}()
+		`, map[string]interface{}{
+			"next": f.doWriteJson("res", f.Type.Modifiers, f.ASTType, false, 1),
+		}),
+	)
 }
 
 func (f *Field) doWriteJson(val string, remainingMods []string, astType *ast.Type, isPtr bool, depth int) string {
@@ -235,7 +243,8 @@ func (f *Field) doWriteJson(val string, remainingMods []string, astType *ast.Typ
 				{{- end }}
 				return graphql.Null
 			}
-			{{.next }}`, map[string]interface{}{
+			{{ .next -}}
+		`, map[string]interface{}{
 			"val":     val,
 			"nonNull": astType.NonNull,
 			"next":    f.doWriteJson(val, remainingMods[1:], astType, true, depth+1),
@@ -289,7 +298,8 @@ func (f *Field) doWriteJson(val string, remainingMods []string, astType *ast.Typ
 				{{- end}}
 			}
 			{{ if and .top (not .isScalar) }} wg.Wait() {{ end }}
-			return {{.arr}}`, map[string]interface{}{
+			return {{ .arr -}}
+		`, map[string]interface{}{
 			"val":      val,
 			"arr":      arr,
 			"index":    index,
@@ -304,7 +314,7 @@ func (f *Field) doWriteJson(val string, remainingMods []string, astType *ast.Typ
 		if isPtr {
 			val = "*" + val
 		}
-		return f.Marshal(val)
+		return "return " + f.Marshal(val)
 
 	default:
 		if !isPtr {

codegen/templates/field.gotpl

@@ -26,7 +26,7 @@
 				return nil
 			}
 			var out graphql.OrderedMap
-			out.Add(field.Alias, func() graphql.Marshaler { {{ $field.WriteJson }} }())
+			out.Add(field.Alias, func() graphql.Marshaler { return {{ $field.WriteJson }} }())
 			return &out
 		}
 	}
@@ -71,6 +71,6 @@
 		}
 		res := resTmp.({{$field.Signature}})
 		rctx.Result = res
-		{{ $field.WriteJson }}
+		return {{ $field.WriteJson }}
 	}
 {{ end }}

codegen/type.go

@@ -163,8 +163,8 @@ func (t Type) Marshal(val string) string {
 	}
 
 	if t.Marshaler != nil {
-		return "return " + t.Marshaler.PkgDot() + "Marshal" + t.Marshaler.GoType + "(" + val + ")"
+		return t.Marshaler.PkgDot() + "Marshal" + t.Marshaler.GoType + "(" + val + ")"
 	}
 
-	return "return " + val
+	return val
 }