songs.go

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
}

songs_test.go

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)
        }
}