如何使用httprouter编写测试

Question

I am writing tests for a simple REST service in GoLang. But, because I am using julienschmidt/httprouter as the routing library. I am struggling on how to write test.

main.go

package main

func main() {
   router := httprouter.New()
   bookController := controllers.NewBookController()
   router.GET("/book/:id", bookController.GetBook)
   http.ListenAndServe(":8080", router)
}

controllers

package controllers

type BookController struct {}

func NewBookController *BookController {
   return &BookController()
}

func (bc BookController) GetBook(w http.ResponseWriter, r *http.Request, p httprouter.Params) {
   fmt.Fprintf(w,"%s", p)
}

My question is: How can test this while GetBook is neither HttpHandler nor HttpHandle

If I use a traditional handler, the test will be easy like this

func TestGetBook(t *testing.T) {
  req, _ := http.NewRequest("GET", "/book/sampleid", nil)
  rr := httptest.NewRecorder()
  handler := controllers.NewBookController().GetBook
  handler.ServeHTTP(rr,req)
  if status := rr.code; status != http.StatusOK {
    t.Errorf("Wrong status")
  }
}

The problem is, httprouter is not handler, or handlefunc. So I am stuck now

Answer 1

Just spin up a new router for each test and then register the handler under test, then pass the test request to the router, not the handler, so that the router can parse the path parameters and pass them to the handler.

func TestGetBook(t *testing.T) {
    handler := controllers.NewBookController()
    router := httprouter.New()
    router.GET("/book/:id", handler.GetBook)

    req, _ := http.NewRequest("GET", "/book/sampleid", nil)
    rr := httptest.NewRecorder()

    router.ServeHTTP(rr, req)
    if status := rr.Code; status != http.StatusOK {
        t.Errorf("Wrong status")
    }
}