Merge pull request #19 from pivotal/PR-fix-start-panic

Allow Start to be called immediately after Stop

writer.go

@@ -107,16 +107,17 @@ func (w *Writer) Flush() error {
 func (w *Writer) Start() {
 	if w.ticker == nil {
 		w.ticker = time.NewTicker(w.RefreshInterval)
-		w.tdone = make(chan bool, 1)
+		w.tdone = make(chan bool)
 	}
 
 	go w.Listen()
 }
 
 // Stop stops the listener that updates the terminal
 func (w *Writer) Stop() {
-	_ = w.Flush()
-	close(w.tdone)
+	w.Flush()
+	w.tdone <- true
+	<-w.tdone
 }
 
 // Listen listens for updates to the writer's buffer and flushes to the out provided. It blocks the runtime.
@@ -132,6 +133,7 @@ func (w *Writer) Listen() {
 			w.ticker.Stop()
 			w.ticker = nil
 			w.mtx.Unlock()
+			close(w.tdone)
 			return
 		}
 	}

writer_test.go

@@ -22,3 +22,14 @@ func TestWriter(t *testing.T) {
 		t.Fatalf("want %q, got %q", want, b.String())
 	}
 }
+
+func TestStartCalledTwice(t *testing.T) {
+	w := New()
+	b := &bytes.Buffer{}
+	w.Out = b
+
+	w.Start()
+	w.Stop()
+	w.Start()
+	w.Stop()
+}