add option to pass custom http.Client to tb.NewBot() in case of proxy…

…ing and other needs

api.go

@@ -26,7 +26,7 @@ func (b *Bot) Raw(method string, payload interface{}) ([]byte, error) {
 		return []byte{}, wrapSystem(err)
 	}
 
-	resp, err := http.Post(url, "application/json", &buf)
+	resp, err := b.client.Post(url, "application/json", &buf)
 	if err != nil {
 		return []byte{}, errors.Wrap(err, "http.Post failed")
 	}
@@ -85,7 +85,7 @@ func (b *Bot) sendFiles(
 
 	req.Header.Add("Content-Type", writer.FormDataContentType())
 
-	resp, err := http.DefaultClient.Do(req)
+	resp, err := b.client.Do(req)
 	if err != nil {
 		return nil, errors.Wrap(err, "http.Post failed")
 	}

bot.go

@@ -20,6 +20,11 @@ func NewBot(pref Settings) (*Bot, error) {
 		pref.Updates = 100
 	}
 
+	client := pref.Client
+	if client == nil {
+		client = http.DefaultClient
+	}
+
 	bot := &Bot{
 		Token:   pref.Token,
 		Updates: make(chan Update, pref.Updates),
@@ -28,6 +33,7 @@ func NewBot(pref Settings) (*Bot, error) {
 		handlers: make(map[string]interface{}),
 		stop:     make(chan struct{}),
 		reporter: pref.Reporter,
+		client:client,
 	}
 
 	user, err := bot.getMe()
@@ -49,6 +55,7 @@ type Bot struct {
 	handlers map[string]interface{}
 	reporter func(error)
 	stop     chan struct{}
+	client   *http.Client
 }
 
 // Settings represents a utility struct for passing certain
@@ -66,6 +73,9 @@ type Settings struct {
 	// Reporter is a callback function that will get called
 	// on any panics recovered from endpoint handlers.
 	Reporter func(error)
+
+	// HTTP Client used to make requests to telegram api
+	Client *http.Client
 }
 
 // Update object represents an incoming update.

telebot_test.go

@@ -26,8 +26,21 @@ func TestBot(t *testing.T) {
 	}
 }
 
-func TestRecipient(_ *testing.T) {
-	bot := Bot{}
+func TestRecipient(t *testing.T) {
+	token := os.Getenv("TELEBOT_SECRET")
+	if token == "" {
+		fmt.Println("ERROR: " +
+			"In order to test telebot functionality, you need to set up " +
+			"TELEBOT_SECRET environmental variable, which represents an API " +
+			"key to a Telegram bot.\n")
+		t.Fatal("Could't find TELEBOT_SECRET, aborting.")
+	}
+
+	bot, err := NewBot(Settings{Token: token})
+	if err != nil {
+		t.Fatal("couldn't create bot:", err)
+	}
+
 	bot.Send(&User{}, "")
 	bot.Send(&Chat{}, "")
 }