add render error test case

render/render_test.go

@@ -8,6 +8,7 @@ import (
 	"bytes"
 	"encoding/xml"
 	"errors"
+	"github.com/stretchr/testify/mock"
 	"html/template"
 	"net/http"
 	"net/http/httptest"
@@ -177,6 +178,46 @@ func TestRenderJsonpJSONError2(t *testing.T) {
 	assert.Equal(t, "application/javascript; charset=utf-8", w.Header().Get("Content-Type"))
 }
 
+type mockResponseRecorder struct {
+	mock.Mock
+	httptest.ResponseRecorder
+}
+
+func (m *mockResponseRecorder) Write(content []byte) (int, error) {
+	args := m.Called(content)
+	return args.Int(0), args.Error(1)
+}
+
+func TestRenderJsonpError3(t *testing.T) {
+	var m *mockResponseRecorder
+
+	data := map[string]interface{}{
+		"foo": "bar",
+	}
+
+	m = new(mockResponseRecorder)
+	m.On("Write", []byte("x")).Return(1, errors.New("mock callback write error"))
+	assert.Error(t, (JsonpJSON{"x", data}).Render(m), "mock callback write error")
+
+	m = new(mockResponseRecorder)
+	m.On("Write", []byte("x")).Return(1, nil)
+	m.On("Write", []byte("(")).Return(1, errors.New("mock ( write error"))
+	assert.Error(t, (JsonpJSON{"x", data}).Render(m), "mock ( write error")
+
+	m = new(mockResponseRecorder)
+	m.On("Write", []byte("x")).Return(1, nil)
+	m.On("Write", []byte("(")).Return(1, nil)
+	m.On("Write", []byte("{\"foo\":\"bar\"}")).Return(1, errors.New("mock ret write error"))
+	assert.Error(t, (JsonpJSON{"x", data}).Render(m), "mock ret write error")
+
+	m = new(mockResponseRecorder)
+	m.On("Write", []byte("x")).Return(1, nil)
+	m.On("Write", []byte("(")).Return(1, nil)
+	m.On("Write", []byte("{\"foo\":\"bar\"}")).Return(1, nil)
+	m.On("Write", []byte(");")).Return(1, errors.New("mock ); write error"))
+	assert.Error(t, (JsonpJSON{"x", data}).Render(m), "mock ); write error")
+}
+
 func TestRenderJsonpJSONFail(t *testing.T) {
 	w := httptest.NewRecorder()
 	data := make(chan int)