Return -1 from GetMax for a bar of unknown length

progressbar.go

@@ -876,19 +876,20 @@ func New64(max int64) *ProgressBar {
 	return NewOptions64(max)
 }
 
-// GetMax returns the max of a bar
+// GetMax returns the max of a bar, or -1 if the length is unknown
 func (p *ProgressBar) GetMax() int {
-	p.lock.Lock()
-	defer p.lock.Unlock()
-
-	return int(p.config.max)
+	return int(p.GetMax64())
 }
 
-// GetMax64 returns the current max
+// GetMax64 returns the current max, or -1 if the length is unknown
 func (p *ProgressBar) GetMax64() int64 {
 	p.lock.Lock()
 	defer p.lock.Unlock()
 
+	// For an unknown length, config.max holds the spinner width, not a max.
+	if p.config.ignoreLength {
+		return -1
+	}
 	return p.config.max
 }
 

progressbar_test.go

@@ -431,6 +431,29 @@ func TestState(t *testing.T) {
 	}
 }
 
+func TestGetMaxUnknownLength(t *testing.T) {
+	bar := NewOptions(-1, OptionSetWriter(io.Discard), OptionSetSpinnerChangeInterval(0))
+	if got := bar.GetMax(); got != -1 {
+		t.Errorf("GetMax() = %d, want -1", got)
+	}
+	if got := bar.GetMax64(); got != -1 {
+		t.Errorf("GetMax64() = %d, want -1", got)
+	}
+	if got := bar.State().Max; got != -1 {
+		t.Errorf("State().Max = %d, want -1", got)
+	}
+
+	bar = NewOptions(100, OptionSetWriter(io.Discard), OptionSetSpinnerChangeInterval(0))
+	bar.ChangeMax(-1)
+	if got := bar.GetMax64(); got != -1 {
+		t.Errorf("after ChangeMax(-1), GetMax64() = %d, want -1", got)
+	}
+	bar.ChangeMax(50)
+	if got := bar.GetMax64(); got != 50 {
+		t.Errorf("after ChangeMax(50), GetMax64() = %d, want 50", got)
+	}
+}
+
 func TestStateBeforeStart(t *testing.T) {
 	for _, tc := range []struct {
 		name     string