diff --git a/bar.go b/bar.go
index 9b0de15..b151da5 100644
--- a/bar.go
+++ b/bar.go
@@ -4,7 +4,6 @@
 	"bytes"
 	"fmt"
 	"io"
-	"os"
 	"sync"
 	"time"
 	"unicode/utf8"
@@ -293,15 +292,16 @@
 }
 
 func (b *Bar) render(tw int, prependWs, appendWs *widthSync) <-chan []byte {
-	ch := make(chan []byte)
+	ch := make(chan []byte, 1)
 
 	go func() {
 		var st state
 		defer func() {
 			// recovering if external decorators panic
 			if p := recover(); p != nil {
-				fmt.Fprintf(os.Stderr, "bar %d: %q\n", st.id, p)
+				ch <- []byte(fmt.Sprintf("bar%02d panic: %q\n", st.id, p))
 			}
+			close(ch)
 		}()
 		result := make(chan state, 1)
 		select {
@@ -320,7 +320,6 @@
 		buf = concatenateBlocks(buf, st.bufP.Bytes(), st.bufB.Bytes(), st.bufA.Bytes())
 		buf = append(buf, '\n')
 		ch <- buf
-		close(ch)
 	}()
 
 	return ch
diff --git a/bar_test.go b/bar_test.go
index 7653a70..48bc62f 100644
--- a/bar_test.go
+++ b/bar_test.go
@@ -142,32 +142,6 @@
 	}
 }
 
-func TestGetSpinner(t *testing.T) {
-	var buf bytes.Buffer
-	p := mpb.New(mpb.Output(&buf))
-	bar := p.AddBar(0, mpb.BarTrim())
-
-	for i := 0; i < 100; i++ {
-		time.Sleep(10 * time.Millisecond)
-		bar.Incr(1)
-	}
-
-	p.Stop()
-
-	spinnerChars := []byte(`-\|/`)
-	seen := make(map[byte]bool)
-	for _, b := range bytes.Trim(buf.Bytes(), "\n") {
-		if !seen[b] {
-			seen[b] = true
-		}
-	}
-	for _, b := range spinnerChars {
-		if !seen[b] {
-			t.Errorf("Char %#U not found in bar's output\n", b)
-		}
-	}
-}
-
 func TestBarGetID(t *testing.T) {
 	var wg sync.WaitGroup
 	var buf bytes.Buffer
@@ -238,7 +212,7 @@
 func TestBarPanics(t *testing.T) {
 	var wg sync.WaitGroup
 	var buf bytes.Buffer
-	p := mpb.New(mpb.Output(&buf))
+	p := mpb.New(mpb.Output(&buf), mpb.WithWaitGroup(&wg))
 
 	wantPanic := "Upps!!!"
 	numBars := 3
@@ -259,19 +233,17 @@
 			defer wg.Done()
 			for i := 0; i < 100; i++ {
 				time.Sleep(10 * time.Millisecond)
-				bar.Incr(1)
+				bar.Increment()
 			}
 		}()
 	}
 
-	wg.Wait()
-	p.Stop()
-
-	bytes := removeLastRune(buf.Bytes())
-	out := strings.Split(string(bytes), "\n")
+	p.Stop()
+
+	out := bytes.Split(removeLastRune(buf.Bytes()), []byte("\n"))
 	gotPanic := out[len(out)-1]
-	if gotPanic != wantPanic {
-		t.Errorf("Want panic: %s, got panic: %s\n", wantPanic, gotPanic)
+	if string(gotPanic) != fmt.Sprintf("bar02 panic: %q", wantPanic) {
+		t.Errorf("Want: %q, got: %q\n", wantPanic, gotPanic)
 	}
 }
 
diff --git a/draw_test.go b/draw_test.go
index 9457d93..0ee810c 100644
--- a/draw_test.go
+++ b/draw_test.go
@@ -1,7 +1,7 @@
 package mpb
 
 import (
-	"reflect"
+	"bytes"
 	"testing"
 )
 
@@ -12,54 +12,68 @@
 		total     int64
 		current   int64
 		barRefill *refill
-		want      []byte
+		want      string
 	}{
-		{
-			termWidth: 1,
-			barWidth:  100,
-			want:      []byte{},
-		},
 		{
 			termWidth: 2,
 			barWidth:  100,
+			want:      "",
+		},
+		{
+			termWidth: 3,
+			barWidth:  100,
 			total:     100,
 			current:   20,
-			want:      []byte("[]"),
+			want:      "[-]",
+		},
+		{
+			termWidth: 5,
+			barWidth:  100,
+			total:     100,
+			current:   20,
+			want:      "[>--]",
+		},
+		{
+			termWidth: 6,
+			barWidth:  100,
+			total:     100,
+			current:   20,
+			want:      "[>---]",
 		},
 		{
 			termWidth: 20,
 			barWidth:  100,
 			total:     100,
 			current:   20,
-			want:      []byte("[===>--------------]"),
+			want:      "[===>--------------]",
 		},
 		{
 			termWidth: 50,
 			barWidth:  100,
 			total:     100,
 			current:   20,
-			want:      []byte("[=========>--------------------------------------]"),
+			want:      "[=========>--------------------------------------]",
 		},
 		{
 			termWidth: 100,
 			barWidth:  100,
 			total:     100,
 			current:   0,
-			want:      []byte("[--------------------------------------------------------------------------------------------------]"),
+			want:      "[--------------------------------------------------------------------------------------------------]",
 		},
 		{
 			termWidth: 100,
 			barWidth:  100,
 			total:     100,
 			current:   1,
-			want:      []byte("[>-------------------------------------------------------------------------------------------------]"),
+			want:      "[>-------------------------------------------------------------------------------------------------]",
 		},
 		{
 			termWidth: 100,
 			barWidth:  100,
 			total:     100,
 			current:   40,
-			want:      []byte("[======================================>-----------------------------------------------------------]"),
+			want:      "[======================================>-----------------------------------------------------------]",
 		},
 		{
 			termWidth: 100,
@@ -67,21 +81,21 @@
 			total:     100,
 			current:   40,
 			barRefill: &refill{'+', 32},
-			want:      []byte("[+++++++++++++++++++++++++++++++=======>-----------------------------------------------------------]"),
+			want:      "[+++++++++++++++++++++++++++++++=======>-----------------------------------------------------------]",
 		},
 		{
 			termWidth: 100,
 			barWidth:  100,
 			total:     100,
 			current:   99,
-			want:      []byte("[================================================================================================>-]"),
+			want:      "[================================================================================================>-]",
 		},
 		{
 			termWidth: 100,
 			barWidth:  100,
 			total:     100,
 			current:   100,
-			want:      []byte("[==================================================================================================]"),
+			want:      "[==================================================================================================]",
 		},
 	}
 
@@ -95,8 +109,10 @@
 		if test.barRefill != nil {
 			s.refill = test.barRefill
 		}
-		got := draw(s, test.termWidth, prependWs, appendWs)
-		if !reflect.DeepEqual(test.want, got) {
+		// got := draw(s, test.termWidth, prependWs, appendWs)
+		s.draw(test.termWidth, prependWs, appendWs)
+		got := s.bufB.String()
+		if got != test.want {
 			t.Errorf("Want: %q, Got: %q\n", test.want, got)
 		}
 	}
@@ -106,6 +122,9 @@
 	s := &state{
 		trimLeftSpace:  true,
 		trimRightSpace: true,
+		bufP:           new(bytes.Buffer),
+		bufB:           new(bytes.Buffer),
+		bufA:           new(bytes.Buffer),
 	}
 	s.updateFormat("[=>-]")
 	return s