我正在使用 Gin 框架编写 REST API。但我在测试我的控制器以及研究 TDD 和 Mock 时遇到了麻烦。我尝试将 TDD 和 Mock 应用于我的代码,但我做不到。
我创建了一个非常精简的测试环境,并尝试创建一个控制器测试。如何为 Gin.Context 创建模拟?
这是我的示例代码:
package main
import (
"strconv"
"github.com/gin-gonic/gin"
)
// MODELS
type Users []User
type User struct {
Name string `json"name"`
}
func main() {
r := gin.Default()
r.GET("/users", GetUsers)
r.GET("/users/:id", GetUser)
r.Run(":8080")
}
// ROUTES
func GetUsers(c *gin.Context) {
repo := UserRepository{}
ctrl := UserController{}
ctrl.GetAll(c, repo)
}
func GetUser(c *gin.Context) {
repo := UserRepository{}
ctrl := UserController{}
ctrl.Get(c, repo)
}
// CONTROLLER
type UserController struct{}
func (ctrl UserController) GetAll(c *gin.Context, repository UserRepositoryIterface) {
c.JSON(200, repository.GetAll())
}
func (ctrl UserController) Get(c *gin.Context, repository UserRepositoryIterface) {
id := c.Param("id")
idConv, _ := strconv.Atoi(id)
c.JSON(200, repository.Get(idConv))
}
// REPOSITORY
type UserRepository struct{}
type UserRepositoryIterface interface {
GetAll() Users
Get(id int) User
}
func (r UserRepository) GetAll() Users {
users := Users{
{Name : "Wilson"},
{Name : "Panda"},
}
return users
}
func (r UserRepository) Get(id int) User {
users := Users{
{Name : "Wilson"},
{Name : "Panda"},
}
return users[id-1]
}
我的测试示例:
package main
import(
"testing"
_ "github.com/gin-gonic/gin"
)
type UserRepositoryMock struct{}
func (r UserRepositoryMock) GetAll() Users {
users := Users{
{Name : "Wilson"},
{Name : "Panda"},
}
return users
}
func (r UserRepositoryMock) Get(id int) User {
users := Users{
{Name : "Wilson"},
{Name : "Panda"},
}
return users[id-1]
}
// TESTING REPOSITORY FUNCTIONS
func TestRepoGetAll(t *testing.T) {
userRepo := UserRepository{}
amountUsers := len(userRepo.GetAll())
if amountUsers != 2 {
t.Errorf("Esperado %d, recebido %d", 2, amountUsers)
}
}
func TestRepoGet(t *testing.T) {
expectedUser := struct{
Name string
}{
"Wilson",
}
userRepo := UserRepository{}
user := userRepo.Get(1)
if user.Name != expectedUser.Name {
t.Errorf("Esperado %s, recebido %s", expectedUser.Name, user.Name)
}
}
/* HOW TO TEST CONTROLLER?
func TestControllerGetAll(t *testing.T) {
gin.SetMode(gin.TestMode)
c := &gin.Context{}
c.Status(200)
repo := UserRepositoryMock{}
ctrl := UserController{}
ctrl.GetAll(c, repo)
}
*/
Gin 提供了创建测试上下文的选项,您可以将其用于您需要的任何用途: https://godoc.org/github.com/gin-gonic/gin#CreateTestContext
像这样:
c, _ := gin.CreateTestContext(httptest.NewRecorder())
这是我如何模拟上下文、添加参数、在函数中使用它,然后在存在非 200 响应时打印响应字符串的示例。
gin.SetMode(gin.TestMode)
w := httptest.NewRecorder()
c, _ := gin.CreateTestContext(w)
c.Params = []gin.Param{gin.Param{Key: "k", Value: "v"}}
foo(c)
if w.Code != 200 {
b, _ := ioutil.ReadAll(w.Body)
t.Error(w.Code, string(b))
}
为了获得可以测试的
*gin.Context
实例,您需要一个模拟 HTTP 请求和响应。创建这些的一个简单方法是使用 net/http
和 net/http/httptest
包。根据您链接的代码,您的测试将如下所示:
package main
import (
"net/http"
"net/http/httptest"
"testing"
"github.com/gin-gonic/gin"
)
func TestControllerGetAll(t *testing.T) {
// Switch to test mode so you don't get such noisy output
gin.SetMode(gin.TestMode)
// Setup your router, just like you did in your main function, and
// register your routes
r := gin.Default()
r.GET("/users", GetUsers)
// Create the mock request you'd like to test. Make sure the second argument
// here is the same as one of the routes you defined in the router setup
// block!
req, err := http.NewRequest(http.MethodGet, "/users", nil)
if err != nil {
t.Fatalf("Couldn't create request: %v\n", err)
}
// Create a response recorder so you can inspect the response
w := httptest.NewRecorder()
// Perform the request
r.ServeHTTP(w, req)
// Check to see if the response was what you expected
if w.Code != http.StatusOK {
t.Fatalf("Expected to get status %d but instead got %d\n", http.StatusOK, w.Code)
}
}
虽然您可以创建一个模拟
*gin.Context
,但使用上面的方法可能更容易,因为它会像实际请求一样执行和处理您的请求。
如果将问题简化为“如何为函数参数创建模拟?”答案是:使用接口而不是具体类型。
type Context struct
是一个具体的类型文字,Gin 没有提供适当的接口。但你可以自己声明。由于您仅使用 JSON
中的 Context
方法,因此您可以声明额外简单的接口:
type JSONer interface {
JSON(code int, obj interface{})
}
并使用
JSONer
类型代替 Context
类型输入所有需要 Context
作为参数的函数:
/* Note, you can't declare argument as a pointer to interface type,
but when you call it you can pass pointer to type which
implements the interface.*/
func GetUsers(c JSONer) {
repo := UserRepository{}
ctrl := UserController{}
ctrl.GetAll(c, repo)
}
func GetUser(c JSONer) {
repo := UserRepository{}
ctrl := UserController{}
ctrl.Get(c, repo)
}
func (ctrl UserController) GetAll(c JSONer, repository UserRepositoryIterface) {
c.JSON(200, repository.GetAll())
}
func (ctrl UserController) Get(c JSONer, repository UserRepositoryIterface) {
id := c.Param("id")
idConv, _ := strconv.Atoi(id)
c.JSON(200, repository.Get(idConv))
}
现在很容易测试了
type ContextMock struct {
JSONCalled bool
}
func (c *ContextMock) JSON(code int, obj interface{}){
c.JSONCalled = true
}
func TestControllerGetAll(t *testing.T) {
gin.SetMode(gin.TestMode)
c := &ContextMock{false}
c.Status(200)
repo := UserRepositoryMock{}
ctrl := UserController{}
ctrl.GetAll(c, repo)
if c.JSONCalled == false {
t.Fail()
}
}