Arg type binding

codegen/args.go

@@ -76,7 +76,12 @@ nextArg:
 		param := params.At(j)
 		for _, oldArg := range field.Args {
 			if strings.EqualFold(oldArg.Name, param.Name()) {
-				oldArg.TypeReference.GO = param.Type()
+				tr, err := b.Binder.TypeReference(oldArg.Type, param.Type())
+				if err != nil {
+					return err
+				}
+				oldArg.TypeReference = tr
+
 				newArgs = append(newArgs, oldArg)
 				continue nextArg
 			}

codegen/config/config.go

@@ -322,7 +322,7 @@ func (c *Config) InjectBuiltins(s *ast.Schema) {
 		"ID": {
 			Model: StringList{
 				"github.com/99designs/gqlgen/graphql.ID",
-				"github.com/99designs/gqlgen/graphql.Int",
+				"github.com/99designs/gqlgen/graphql.IntID",
 			},
 		},
 	}

example/todo/gqlgen.yml

@@ -1,3 +1,7 @@
 models:
   Todo:
     model: github.com/99designs/gqlgen/example/todo.Todo
+  ID:
+    model: # override the default id marshaller to use ints
+      - github.com/99designs/gqlgen/graphql.IntID
+      - github.com/99designs/gqlgen/graphql.ID

example/todo/schema.graphql

@@ -4,14 +4,14 @@ schema {
 }
 
 type MyQuery {
-    todo(id: Int!): Todo
+    todo(id: ID!): Todo
     lastTodo: Todo
     todos: [Todo!]!
 }
 
 type MyMutation {
     createTodo(todo: TodoInput!): Todo!
-    updateTodo(id: Int!, changes: Map!): Todo
+    updateTodo(id: ID!, changes: Map!): Todo
 }
 
 type Todo {

example/todo/todo_test.go

@@ -15,18 +15,18 @@ func TestTodo(t *testing.T) {
 	c := client.New(srv.URL)
 
 	var resp struct {
-		CreateTodo struct{ ID int }
+		CreateTodo struct{ ID string }
 	}
 	c.MustPost(`mutation { createTodo(todo:{text:"Fery important"}) { id } }`, &resp)
 
-	require.Equal(t, 5, resp.CreateTodo.ID)
+	require.Equal(t, "5", resp.CreateTodo.ID)
 
 	t.Run("update the todo text", func(t *testing.T) {
 		var resp struct {
 			UpdateTodo struct{ Text string }
 		}
 		c.MustPost(
-			`mutation($id: Int!, $text: String!) { updateTodo(id: $id, changes:{text:$text}) { text } }`,
+			`mutation($id: ID!, $text: String!) { updateTodo(id: $id, changes:{text:$text}) { text } }`,
 			&resp,
 			client.Var("id", 5),
 			client.Var("text", "Very important"),
@@ -58,12 +58,12 @@ func TestTodo(t *testing.T) {
 	t.Run("select with alias", func(t *testing.T) {
 		var resp struct {
 			A struct{ Text string }
-			B struct{ ID int }
+			B struct{ ID string }
 		}
 		c.MustPost(`{ a: todo(id:1) { text } b: todo(id:2) { id } }`, &resp)
 
 		require.Equal(t, "A todo not to forget", resp.A.Text)
-		require.Equal(t, 2, resp.B.ID)
+		require.Equal(t, "2", resp.B.ID)
 	})
 
 	t.Run("find a missing todo", func(t *testing.T) {
@@ -101,17 +101,17 @@ func TestTodo(t *testing.T) {
 	t.Run("select all", func(t *testing.T) {
 		var resp struct {
 			Todo struct {
-				ID   int
+				ID   string
 				Text string
 				Done bool
 			}
 			LastTodo struct {
-				ID   int
+				ID   string
 				Text string
 				Done bool
 			}
 			Todos []struct {
-				ID   int
+				ID   string
 				Text string
 			}
 		}
@@ -121,11 +121,11 @@ func TestTodo(t *testing.T) {
 			todos { id text }
 		}`, &resp)
 
-		require.Equal(t, 1, resp.Todo.ID)
-		require.Equal(t, 5, resp.LastTodo.ID)
+		require.Equal(t, "1", resp.Todo.ID)
+		require.Equal(t, "5", resp.LastTodo.ID)
 		require.Len(t, resp.Todos, 5)
 		require.Equal(t, "Very important", resp.LastTodo.Text)
-		require.Equal(t, 5, resp.LastTodo.ID)
+		require.Equal(t, "5", resp.LastTodo.ID)
 	})
 
 	t.Run("introspection", func(t *testing.T) {

graphql/id.go

@@ -34,3 +34,24 @@ func UnmarshalID(v interface{}) (string, error) {
 		return "", fmt.Errorf("%T is not a string", v)
 	}
 }
+
+func MarshalIntID(i int) Marshaler {
+	return WriterFunc(func(w io.Writer) {
+		writeQuotedString(w, strconv.Itoa(i))
+	})
+}
+
+func UnmarshalIntID(v interface{}) (int, error) {
+	switch v := v.(type) {
+	case string:
+		return strconv.Atoi(v)
+	case int:
+		return v, nil
+	case int64:
+		return int(v), nil
+	case json.Number:
+		return strconv.Atoi(string(v))
+	default:
+		return 0, fmt.Errorf("%T is not an int", v)
+	}
+}