mockserver

I have seen no good example or explanation on mocking when it comes to doing integration testing. You don't want your tests to always all a third party API or you need to create a mockserver of your API. Either way, the key feature about this mockserver is ROUTING which I went with httprouter because I like speed. There is helper functions to generate one off httptest.Server for JSON and XML as well a simple one.

This merely is exposing the unmodified power of routing from httprouter to testing.

Let's get this party started

Routes (borrowed from the routing tests)

package your_test

import (
	"bytes"
	"fmt"
	"net/http"

	"github.com/apriendeau/mockserver"
	"github.com/stretchr/testify/assert"
)

func sampleRoutes() []mockserver.Route {
	first := mockserver.Route{
		Method: "GET",
		Path:   "/hello/world",
		Handle: httprouter.Handle(func(w http.ResponseWriter, r *http.Request, p httprouter.Params) {
			w.WriteHeader(200)
			w.Header().Set("Content-Type", "plain/text")
			fmt.Fprint(w, "Hello world")
		}),
	}
	second := mockserver.Route{
		Method: "POST",
		Path:   "/welcome/:name",
		Handle: httprouter.Handle(func(w http.ResponseWriter, r *http.Request, p httprouter.Params) {
			w.WriteHeader(200)
			w.Header().Set("Content-Type", "plain/text")
			fmt.Fprint(w, "Welcome ", p.ByName("name"))
		}),
	}
	return []mockserver.Route{first, second}
}

func TestAllTheThings(t *testing) {
	assert := assert.New(t)
	routes := sampleRoutes()
	server := mockserver.WithRoutes(routes)
	defer server.Close()

	resp, err := http.Get(server.URL + "/random")
	assert.NoError(err)
	// This will pass
	assert.Equal(404, resp.StatusCode)

	// How about some parameters
	resp, err = http.Post(server.URL+"/welcome/tony", "plain/text", bytes.NewBuffer([]byte{}))
	assert.NoError(err)
	assert.Equal(200, resp.StatusCode)
	body, err := parseResp(resp.Body)
	assert.NoError(err)
	assert.Equal(body, "Welcome tony") // Booyah biz-nitches

	// How about the same route but an umplemented method?
	resp, err = http.Get(server.URL + "/welcome/tony")
	assert.NoError(err)
	assert.Equal(405, resp.StatusCode) // again, booyah.
}

FAQs

Q. Can you create more than one server in a function?

A. Yes, you can because mockserver is just riding on top of httptest.Server. This also prevents url and port collisions so you can spin up several different mocks for you.

Q. Why do I have to close the server?

A. mockserver cannot predict when you are done with your tests so you can defer or you can close at the end since this is just helper functions around httptest.

Q. What sparked the desire?

A. Well, integration/functional testing when building a PaaS service on top of Mesosphere is rather annoying and slow to spin up several docker containers with each service so now, I can create mocks of those APIs with ease.

Q. Can I use an existing router?

A. Yes, you can if it implements http.Handle interface. Here is an example using httprouter.

mockserver.HandlerFunc(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request){
	router := httprouter.New()
	router.ServerHTTP(w,r)
}))

Contributing

Feel free to create issues and PRs. All is welcome.