Testing HTTP Clients with Go

client.go

package main

import (
	"io/ioutil"
	"log"
	"net/http"
)

type RealWebClient struct {
}

type WebClient interface {
	Get(string) []byte
}

type Client struct {
	Http WebClient
}

func (r *RealWebClient) Get(url string) []byte {
	var body []byte
	// Raw link: https://registry.hub.docker.com/u/bfirsh/ffmpeg/dockerfile/raw
	client := &http.Client{}
	req, _ := http.NewRequest("GET", url, nil)

	if resp, err := client.Do(req); nil != err {
		log.Fatal(err)
	} else {
		defer resp.Body.Close()
		body, _ = ioutil.ReadAll(resp.Body)
	}
	return body
}

client_test.go

package main

import (
	"fmt"
	"strings"
	"testing"
)

type MockWebClient struct {
}

func getTestClient() *Client {
	c := new(Client)
	c.Http = new(MockWebClient)
	return c
}

var jsonSample = ` { "fake" : "data" } `

func TestFullCircle(t *testing.T) {
	c := getTestClient()
	result := c.Http.Get("http://google.com")

	if -1 != strings.Index(string(result), "fake") {
		fmt.Println("We got our fake JSON data")
	}
}

func (mwc *MockWebClient) Get(url string) []byte {
	var rv []byte
	if -1 != strings.Index(url, "google.com") {
		// Return the JSON
		rv = []byte(jsonSample)
	}
	return rv
}

tool.go

package main

import "fmt"

func main() {
	c := new(Client)
	c.Http = new(RealWebClient)
	body := c.Http.Get("http://google.com")
	fmt.Println("Result\n\n" + string(body))
}