Do not bind to unexported vars or methods

example/todo/generated.go

@@ -261,9 +261,9 @@ func (ec *executionContext) _todo(sel []query.Selection, it *Todo) jsonw.Writer
 
 		switch field.Name {
 		case "id":
-			res := it.ID
+			res := it.ID()
 
-			out.Values[i] = jsonw.Int(res)
+			out.Values[i] = jsonw.String(res)
 		case "text":
 			res := it.Text
 
@@ -705,7 +705,7 @@ func (ec *executionContext) ___Type(sel []query.Selection, it *introspection.Typ
 	return out
 }
 
-var parsedSchema = schema.MustParse("schema {\n\tquery: MyQuery\n\tmutation: MyMutation\n}\n\ntype MyQuery {\n\ttodo(id: Int!): Todo\n\tlastTodo: Todo\n\ttodos: [Todo!]!\n}\n\ntype MyMutation {\n\tcreateTodo(text: String!): Todo!\n\tupdateTodo(id: Int!, changes: TodoInput!): Todo\n}\n\ntype Todo {\n\tid: Int!\n\ttext: String!\n\tdone: Boolean!\n}\n\ninput TodoInput {\n\ttext: String\n\tdone: Boolean\n}\n")
+var parsedSchema = schema.MustParse("schema {\n\tquery: MyQuery\n\tmutation: MyMutation\n}\n\ntype MyQuery {\n\ttodo(id: Int!): Todo\n\tlastTodo: Todo\n\ttodos: [Todo!]!\n}\n\ntype MyMutation {\n\tcreateTodo(text: String!): Todo!\n\tupdateTodo(id: Int!, changes: TodoInput!): Todo\n}\n\ntype Todo {\n\tid: ID!\n\ttext: String!\n\tdone: Boolean!\n}\n\ninput TodoInput {\n\ttext: String\n\tdone: Boolean\n}\n")
 
 func (ec *executionContext) introspectSchema() *introspection.Schema {
 	return introspection.WrapSchema(parsedSchema)

example/todo/schema.graphql

@@ -15,7 +15,7 @@ type MyMutation {
 }
 
 type Todo {
-	id: Int!
+	id: ID!
 	text: String!
 	done: Boolean!
 }

example/todo/todo.go

@@ -7,14 +7,19 @@ import (
 	"errors"
 	"time"
 
+	"strconv"
+
 	"github.com/mitchellh/mapstructure"
 )
 
 type Todo struct {
-	ID     int
-	Text   string
-	Done   bool
-	UserID int
+	id   int
+	Text string
+	Done bool
+}
+
+func (t *Todo) ID() string {
+	return "t" + strconv.Itoa(t.id)
 }
 
 type todoResolver struct {
@@ -25,9 +30,9 @@ type todoResolver struct {
 func New() *todoResolver {
 	return &todoResolver{
 		todos: []Todo{
-			{ID: 1, Text: "A todo not to forget", Done: false, UserID: 1},
-			{ID: 2, Text: "This is the most important", Done: false, UserID: 1},
-			{ID: 3, Text: "Please do this or else", Done: false, UserID: 1},
+			{id: 1, Text: "A todo not to forget", Done: false},
+			{id: 2, Text: "This is the most important", Done: false},
+			{id: 3, Text: "Please do this or else", Done: false},
 		},
 		lastID: 3,
 	}
@@ -36,7 +41,7 @@ func New() *todoResolver {
 func (r *todoResolver) MyQuery_todo(ctx context.Context, id int) (*Todo, error) {
 	time.Sleep(220 * time.Millisecond)
 	for _, todo := range r.todos {
-		if todo.ID == id {
+		if todo.id == id {
 			return &todo, nil
 		}
 	}
@@ -58,7 +63,7 @@ func (r *todoResolver) MyMutation_createTodo(ctx context.Context, text string) (
 	newID := r.id()
 
 	newTodo := Todo{
-		ID:   newID,
+		id:   newID,
 		Text: text,
 		Done: false,
 	}
@@ -74,7 +79,7 @@ func (r *todoResolver) MyMutation_updateTodo(ctx context.Context, id int, change
 	var affectedTodo *Todo
 
 	for i := 0; i < len(r.todos); i++ {
-		if r.todos[i].ID == id {
+		if r.todos[i].id == id {
 			affectedTodo = &r.todos[i]
 			break
 		}

example/todo/todo_test.go

@@ -17,16 +17,16 @@ func TestTodo(t *testing.T) {
 
 	t.Run("create a new todo", func(t *testing.T) {
 		var resp struct {
-			CreateTodo Todo
+			CreateTodo struct{ ID string }
 		}
 		c.MustPost(`mutation { createTodo(text:"Fery important") { id } }`, &resp)
 
-		require.Equal(t, 4, resp.CreateTodo.ID)
+		require.Equal(t, "t4", resp.CreateTodo.ID)
 	})
 
 	t.Run("update the todo text", func(t *testing.T) {
 		var resp struct {
-			UpdateTodo Todo
+			UpdateTodo struct{ Text string }
 		}
 		c.MustPost(`mutation { updateTodo(id: 4, changes:{text:"Very important"}) { text } }`, &resp)
 
@@ -35,7 +35,7 @@ func TestTodo(t *testing.T) {
 
 	t.Run("update the todo status", func(t *testing.T) {
 		var resp struct {
-			UpdateTodo Todo
+			UpdateTodo struct{ Text string }
 		}
 		c.MustPost(`mutation { updateTodo(id: 4, changes:{done:true}) { text } }`, &resp)
 
@@ -44,35 +44,44 @@ func TestTodo(t *testing.T) {
 
 	t.Run("select with alias", func(t *testing.T) {
 		var resp struct {
-			A Todo
-			B Todo
+			A struct{ Text string }
+			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, 0, resp.A.ID)
-
-		require.Equal(t, "", resp.B.Text)
-		require.Equal(t, 2, resp.B.ID)
+		require.Equal(t, "t2", resp.B.ID)
 	})
 
 	t.Run("select all", func(t *testing.T) {
 		var resp struct {
-			Todo     Todo
-			LastTodo Todo
-			Todos    []Todo
+			Todo struct {
+				ID   string
+				Text string
+				Done bool
+			}
+			LastTodo struct {
+				ID   string
+				Text string
+				Done bool
+			}
+			Todos []struct {
+				ID   string
+				Text string
+				Done bool
+			}
 		}
 		c.MustPost(`{
 			todo(id:1) { id done text }
 			lastTodo { id text done }
 			todos { id text done }
 		}`, &resp)
 
-		require.Equal(t, 1, resp.Todo.ID)
-		require.Equal(t, 4, resp.LastTodo.ID)
+		require.Equal(t, "t1", resp.Todo.ID)
+		require.Equal(t, "t4", resp.LastTodo.ID)
 		require.Len(t, resp.Todos, 4)
 		require.Equal(t, "Very important", resp.LastTodo.Text)
-		require.Equal(t, 4, resp.LastTodo.ID)
+		require.Equal(t, "t4", resp.LastTodo.ID)
 	})
 
 	t.Run("introspection", func(t *testing.T) {

extractor.go

@@ -323,6 +323,10 @@ func (e *extractor) findBindTargets(t types.Type, object *object) bool {
 	case *types.Named:
 		for i := 0; i < t.NumMethods(); i++ {
 			method := t.Method(i)
+			if !method.Exported() {
+				continue
+			}
+
 			if methodField := object.GetField(method.Name()); methodField != nil {
 				methodField.MethodName = "it." + method.Name()
 				sig := method.Type().(*types.Signature)
@@ -362,6 +366,10 @@ func (e *extractor) findBindTargets(t types.Type, object *object) bool {
 			field := t.Field(i)
 			// Todo: struct tags, name and - at least
 
+			if !field.Exported() {
+				continue
+			}
+
 			// Todo: check for type matches before binding too?
 			if objectField := object.GetField(field.Name()); objectField != nil {
 				objectField.VarName = "it." + field.Name()