remove panic in Render

Change-Id: Ifd7778ec44ea87d18b2156c97c88130f3ec72022

context.go

@@ -894,7 +894,8 @@ func (c *Context) Render(code int, r render.Render) {
 	}
 
 	if err := r.Render(c.Writer); err != nil {
-		panic(err)
+		c.Error(err)
+		c.Abort()
 	}
 }
 

context_test.go

@@ -642,25 +642,21 @@ func TestContextBodyAllowedForStatus(t *testing.T) {
 	assert.True(t, true, bodyAllowedForStatus(http.StatusInternalServerError))
 }
 
-type TestPanicRender struct{}
+type TestErrorRender struct{}
 
-func (*TestPanicRender) Render(http.ResponseWriter) error {
-	return errors.New("TestPanicRender")
+var errTestPanicRender = errors.New("TestPanicRender")
+
+func (*TestErrorRender) Render(http.ResponseWriter) error {
+	return errTestPanicRender
 }
 
-func (*TestPanicRender) WriteContentType(http.ResponseWriter) {}
+func (*TestErrorRender) WriteContentType(http.ResponseWriter) {}
 
 func TestContextRenderPanicIfErr(t *testing.T) {
-	defer func() {
-		r := recover()
-		assert.Equal(t, "TestPanicRender", fmt.Sprint(r))
-	}()
 	w := httptest.NewRecorder()
 	c, _ := CreateTestContext(w)
-
-	c.Render(http.StatusOK, &TestPanicRender{})
-
-	assert.Fail(t, "Panic not detected")
+	c.Render(http.StatusOK, &TestErrorRender{})
+	assert.Equal(t, errorMsgs{&Error{Err: errTestPanicRender, Type: 1}}, c.Errors)
 }
 
 // Tests that the response is serialized as JSON

render/json.go

@@ -54,10 +54,7 @@ var (
 
 // Render (JSON) writes data with custom ContentType.
 func (r JSON) Render(w http.ResponseWriter) (err error) {
-	if err = WriteJSON(w, r.Data); err != nil {
-		panic(err)
-	}
-	return
+	return WriteJSON(w, r.Data)
 }
 
 // WriteContentType (JSON) writes JSON ContentType.

render/render_test.go

@@ -39,12 +39,12 @@ func TestRenderJSON(t *testing.T) {
 	assert.Equal(t, "application/json; charset=utf-8", w.Header().Get("Content-Type"))
 }
 
-func TestRenderJSONPanics(t *testing.T) {
+func TestRenderJSONError(t *testing.T) {
 	w := httptest.NewRecorder()
 	data := make(chan int)
 
 	// json: unsupported type: chan int
-	assert.Panics(t, func() { assert.NoError(t, (JSON{data}).Render(w)) })
+	assert.Error(t, (JSON{data}).Render(w))
 }
 
 func TestRenderIndentedJSON(t *testing.T) {