When reducing terminal size, bar will not remain in the same line in each rendering. Is it a bug?

• Device: MacBook Pro 13-inch, 2020
• Terminal: build-in Terminal application
• Description:
  • After the width of terminal got thinner, the previous bar remain above (which is acceptable).
  • But the new bar kept starting new lines and re-render each progress, which may not be acceptable.
  • Please refer to attached screen capture file.

source test file content:

package progress

import (
	"os"
	"testing"
	"time"

	progressbar "github.com/schollz/progressbar/v3"
	. "github.com/smartystreets/goconvey/convey"
	"golang.org/x/term"
)

func TestGeneral(t *testing.T) {
	Convey("progressbar", t, func() { testProgressbar(t) })
}

func testProgressbar(t *testing.T) {
	bar := progressbar.Default(100, "test progressbar")

	for i := 0; i < 100; i++ {
		bar.Set(i)
		time.Sleep(50 * time.Millisecond)
	}

	bar.Clear()
	w, h, err := term.GetSize(int(os.Stdout.Fd()))
	So(err, ShouldBeNil)
	t.Logf("Done, terminal size: %d x %d", w, h)
}

https://user-images.githubusercontent.com/6083108/131773460-a44c00ec-7065-4d05-8d85-1ad95ab09146.mov

Start with the provided Go test, especially TestGeneral and testProgressbar, and reproduce the behavior in the macOS Terminal while narrowing the terminal width. Inspect the progress bar's rendering and terminal-size handling to determine whether each update should remain on one line after resizing. Done means the behavior is reproduced, clarified, and covered by a regression test.