How to test http calls in Go using httptest

I have the following code:

package main


import (
"encoding/json"
"fmt"
"io/ioutil"
"log"
"net/http"
"time"
)


type twitterResult struct {
Results []struct {
Text     string `json:"text"`
Ids      string `json:"id_str"`
Name     string `json:"from_user_name"`
Username string `json:"from_user"`
UserId   string `json:"from_user_id_str"`
}
}


var (
twitterUrl = "http://search.twitter.com/search.json?q=%23UCL"
pauseDuration = 5 * time.Second
)


func retrieveTweets(c chan<- *twitterResult) {
for {
resp, err := http.Get(twitterUrl)
if err != nil {
log.Fatal(err)
}


defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
r := new(twitterResult) //or &twitterResult{} which returns *twitterResult
err = json.Unmarshal(body, &r)
if err != nil {
log.Fatal(err)
}
c <- r
time.Sleep(pauseDuration)
}


}


func displayTweets(c chan *twitterResult) {
tweets := <-c
for _, v := range tweets.Results {
fmt.Printf("%v:%v\n", v.Username, v.Text)
}


}


func main() {
c := make(chan *twitterResult)
go retrieveTweets(c)
for {
displayTweets(c)
}


}

我想为它编写一些测试，但我不确定如何使用httptest包http://golang.org/pkg/net/http/httptest/将感谢一些指点。

I came up with this (shamelessly copied from the tests for go OAuth https://code.google.com/p/goauth2/source/browse/oauth/oauth_test.go):

var request = struct {
path, query       string // request
contenttype, body string // response
}{
path:        "/search.json?",
query:       "q=%23Kenya",
contenttype: "application/json",
body:        twitterResponse,
}


var (
twitterResponse = `{ 'results': [{'text':'hello','id_str':'34455w4','from_user_name':'bob','from_user_id_str':'345424'}]}`
)


func TestRetrieveTweets(t *testing.T) {
handler := func(w http.ResponseWriter, r *http.Request) {


w.Header().Set("Content-Type", request.contenttype)
io.WriteString(w, request.body)
}


server := httptest.NewServer(http.HandlerFunc(handler))
defer server.Close()


resp, err := http.Get(server.URL)
if err != nil {
t.Fatalf("Get: %v", err)
}
checkBody(t, resp, twitterResponse)
}


func checkBody(t *testing.T, r *http.Response, body string) {
b, err := ioutil.ReadAll(r.Body)
if err != nil {
t.Error("reading reponse body: %v, want %q", err, body)
}
if g, w := string(b), body; g != w {
t.Errorf("request body mismatch: got %q, want %q", g, w)
}
}

74543

小开

httptest does two types of tests: response and server

Response test:

func TestHeader3D(t *testing.T) {
resp := httptest.NewRecorder()


uri := "/3D/header/?"
path := "/home/test"
unlno := "997225821"


param := make(url.Values)
param["param1"] = []string{path}
param["param2"] = []string{unlno}


req, err := http.NewRequest("GET", uri+param.Encode(), nil)
if err != nil {
t.Fatal(err)
}


http.DefaultServeMux.ServeHTTP(resp, req)
if p, err := ioutil.ReadAll(resp.Body); err != nil {
t.Fail()
} else {
if strings.Contains(string(p), "Error") {
t.Errorf("header response shouldn't return error: %s", p)
} else if !strings.Contains(string(p), `expected result`) {
t.Errorf("header response doen't match:\n%s", p)
}
}
}

Server test (which is what you need to use):

func TestIt(t *testing.T){
ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Content-Type", "application/json")
fmt.Fprintln(w, `{"fake twitter json string"}`)
}))
defer ts.Close()


twitterUrl = ts.URL
c := make(chan *twitterResult)
go retrieveTweets(c)


tweet := <-c
if tweet != expected1 {
t.Fail()
}
tweet = <-c
if tweet != expected2 {
t.Fail()
}
}

BTW, you don't need to pass in the pointer of r, because it's already a pointer.

err = json.Unmarshal(body, r)

EDIT: for my recorder test, I could use my http handler like this:

handler(resp, req)

But my original code is not using the default mux (but from Gorilla/mux), and I have some wrapping around the mux, e.g. insert server logging, and adding request context (Gorilla/context), so I had to start from mux and call ServeHTTP