测试Go(Golang)API传出请求而不实际触及第三方API

Question

我正在开发一个Go API,它在内部后端和几个第三方API之间进行转换.我试图了解如何在不实际使用外部API的情况下测试其功能.

例如,这是一个处理传入请求以制作新歌曲的服务器,并将请求发送给第三方API:

package main

import (
        "bytes"
        "encoding/json"
        "fmt"
        "net/http"
)

var ThirdPartyApi = "http://www.coolsongssite.api"

type IncomingRequest struct {
        username string         `json:"username"`
        password string         `json:"password"`
        songs    []IncomingSong `json:"songs"`
}

type OutgoingRequest struct {
        username string         `json:"username"`
        password string         `json:"password"`
        songs    []OutgoingSong `json:"songs"`
}

type IncomingSong struct {
        artist string `json:"artist"`
        album  string `json:"album"`
        title  string `json:"title"`
}

type OutgoingSong struct {
        musician string `json:"musician"`
        record   string `json:"record"`
        name     string `json:"name"`
}

func main() {
        http.HandleFunc("/songs/create", createSong)
        http.ListenAndServe(":8080", nil)
}

func createSong(rw http.ResponseWriter, req *http.Request) {
         decoder := json.NewDecoder(req.Body)
         var incomingRequest IncomingRequest
         decoder.Decode(&incomingRequest)
         outgoingRequest := incomingRequestToOutgoingRequest(incomingRequest)

         r, _ := json.Marshal(outgoingRequest)
         request, _ := http.NewRequest("POST", ThirdPartyApi, bytes.NewBuffer(r))
         request.Header.Set("Content-Type", "application/json")

         client := http.Client{}

         response, _ := client.Do(request)
         fmt.Fprintln(rw, response)
}

func incomingRequestToOutgoingRequest(inc IncomingRequest) OutgoingRequest {
        outgoingRequest := OutgoingRequest{
                username: inc.username,
                password: inc.password,
        }

        for _, s := range inc.songs {
                outgoingRequest.songs = append(
                        outgoingRequest.songs, OutgoingSong{
                                musician: s.artist,
                                record:   s.album,
                                name:     s.title,
                        },
                )
        }

        return outgoingRequest
}

所以我可能localhost:8080用这样的东西点击运行的应用程序:

curl -X POST http://localhost:8080/songs/new --data \
'{"username": "<my-username>", "password": "<my-password>", "songs": \
["artist": "<song-artist>", "title": "<song-title>", "album": "<song-album>"]}'

我的问题是:我如何编写测试来测试发出的请求(在这种情况下http://www.coolsongssite.api)是否正确,而不实际发送？

我应该重写createSong处理程序,以便我可以隔离正在发生的事情client.Do(request)吗？

任何有关正确方向的帮助/建议/要点都会受到赞赏.

在这里我可以这样测试incomingRequestToOutgoingRequest:

package main

import (
        "testing"
)

func TestincomingRequestToOutgoingRequest(t *testing.T) {
        incomingRequest := IncomingRequest{
                username: "myuser",
                password: "mypassword",
        }

        var songs []IncomingSong
        songs = append(
                songs, IncomingSong{
                artist: "White Rabbits",
                album:  "Milk Famous",
                title:  "I'm Not Me",
                },
        )

        outgoingRequest := incomingRequestToOutgoingRequest(incomingRequest)

        if outgoingRequest.songs[0].musician != "White Rabbits" {
                t.Error("Expected musican name to be 'White Rabbits'. Got: ", outgoingRequest.songs[0].musician)
        }
}

Answer 1

你可以net/http/httptest.NewServer像这样使用:

ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
    w.Write([]byte(`desired response here`))
}))
defer ts.Close()
ThirdPartyAPI = ts.URL
...
your test here