Use errcheck to find unhandled errors (#795)

Signed-off-by: Chris Cummer <chriscummer@me.com>

modules/spotifyweb/keyboard.go

@@ -19,30 +19,47 @@ func (widget *Widget) initializeKeyboardControls() {
 }
 
 func (widget *Widget) selectPrevious() {
-	widget.client.Previous()
+	err := widget.client.Previous()
+	if err != nil {
+		return
+	}
+
 	time.Sleep(time.Millisecond * 500)
 	widget.Refresh()
 }
 
 func (widget *Widget) selectNext() {
-	widget.client.Next()
+	err := widget.client.Next()
+	if err != nil {
+		return
+	}
+
 	time.Sleep(time.Millisecond * 500)
 	widget.Refresh()
 }
 
 func (widget *Widget) playPause() {
+	var err error
 	if widget.playerState.CurrentlyPlaying.Playing {
-		widget.client.Pause()
+		err = widget.client.Pause()
 	} else {
-		widget.client.Play()
+		err = widget.client.Play()
 	}
+	if err != nil {
+		return
+	}
+
 	time.Sleep(time.Millisecond * 500)
 	widget.Refresh()
 }
 
 func (widget *Widget) toggleShuffle() {
 	widget.playerState.ShuffleState = !widget.playerState.ShuffleState
-	widget.client.Shuffle(widget.playerState.ShuffleState)
+	err := widget.client.Shuffle(widget.playerState.ShuffleState)
+	if err != nil {
+		return
+	}
+
 	time.Sleep(time.Millisecond * 500)
 	widget.Refresh()
 }

modules/spotifyweb/widget.go

@@ -53,7 +53,10 @@ func authHandler(w http.ResponseWriter, r *http.Request) {
 	}
 	// use the token to get an authenticated client
 	client := auth.NewClient(tok)
-	fmt.Fprintf(w, "Login Completed!")
+	_, err = fmt.Fprintf(w, "Login Completed!")
+	if err != nil {
+		return
+	}
 	tempClientChan <- &client
 }
 
@@ -81,7 +84,12 @@ func NewWidget(app *tview.Application, pages *tview.Pages, settings *Settings) *
 	}
 
 	http.HandleFunc("/callback", authHandler)
-	go http.ListenAndServe(":"+callbackPort, nil)
+	go func() {
+		err := http.ListenAndServe(":"+callbackPort, nil)
+		if err != nil {
+			return
+		}
+	}()
 
 	go func() {
 		// wait for auth to complete