Explicit newline if string is not cleared after finish

Fixes schollz#75

progressbar.go

@@ -585,6 +585,13 @@ func (p *ProgressBar) render() error {
 		}
 	}
 	if p.state.finished {
+		// append a newline if we're leaving the progressbar around
+		if !p.config.clearOnFinish {
+			if _, err := p.config.writer.Write([]byte{'\n'}); err != nil {
+				return err
+			}
+		}
+
 		// when using ANSI codes we don't pre-clean the current line
 		if p.config.useANSICodes {
 			err := clearProgressBar(p.config, p.state)
@@ -679,7 +686,6 @@ func renderProgressBar(c config, s *state) (int, error) {
 					bytesString += fmt.Sprintf("%s/%s%s", currentHumanize, c.maxHumanized, c.maxHumanizedSuffix)
 				} else {
 					bytesString += fmt.Sprintf("%s%s/%s%s", currentHumanize, currentSuffix, c.maxHumanized, c.maxHumanizedSuffix)
-
 				}
 			} else {
 				bytesString += fmt.Sprintf("%.0f/%d", s.currentBytes, c.max)

progressbar_test.go

@@ -17,6 +17,34 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
+// clearBuffer simulates lines printed to the screen. Any carriage returns will
+// reset the beginning of the accumulated bytes, while any newline will write
+// accumulated bytes. Useful for testing against how the screen would appear
+type clearBuffer struct {
+	b []byte
+}
+
+func (c *clearBuffer) Write(p []byte) (int, error) {
+	start := 0
+	for i, b := range p {
+		switch b {
+		case '\r':
+			start = i + 1
+		case '\n':
+			c.b = append(c.b, p[start:i+1]...)
+			start = i + 1
+		}
+	}
+	if start < len(p) {
+		c.b = append(c.b, p[start:]...)
+	}
+	return len(p), nil
+}
+
+func (c *clearBuffer) String() string {
+	return string(c.b)
+}
+
 func BenchmarkRender(b *testing.B) {
 	bar := NewOptions64(100000000,
 		OptionSetWriter(os.Stderr),
@@ -87,6 +115,7 @@ func ExampleOptionClearOnFinish() {
 	// Output:
 	// Finished
 }
+
 func ExampleProgressBar_Finish() {
 	bar := NewOptions(100, OptionSetWidth(10), OptionSetRenderBlankState(false))
 	bar.Finish()
@@ -502,7 +531,6 @@ func TestConcurrency(t *testing.T) {
 }
 
 func TestIterationNames(t *testing.T) {
-
 	b := Default(20)
 	tc := b.config
 
@@ -520,6 +548,28 @@ func TestIterationNames(t *testing.T) {
 	}
 }
 
+func TestNoClear(t *testing.T) {
+	buf := &clearBuffer{}
+	bar := NewOptions(100, OptionSetWidth(10), OptionSetWriter(buf))
+	bar.Finish()
+	bar = NewOptions(100, OptionSetWidth(10), OptionSetWriter(buf))
+	bar.Finish()
+	want := " 100% |██████████| \n 100% |██████████| \n"
+	if buf.String() != want {
+		t.Errorf("Expected to see two lines:\n%s instead I got:\n%s\n", want, buf.String())
+	}
+
+	buf = &clearBuffer{}
+	bar = NewOptions(100, OptionSetWidth(10), OptionClearOnFinish(), OptionSetWriter(buf))
+	bar.Finish()
+	bar = NewOptions(100, OptionSetWidth(10), OptionClearOnFinish(), OptionSetWriter(buf))
+	bar.Finish()
+	want = ""
+	if buf.String() != want {
+		t.Errorf("Expected to see no lines, instead I got:\n%s\n", buf.String())
+	}
+}
+
 func md5sum(r io.Reader) (string, error) {
 	hash := md5.New()
 	_, err := io.Copy(hash, r)