golang io.writer new line after finished writing string

Question

I have the following code that uses a package to draw a progress bar

type tmpStruct struct {
}

func (t *tmpStruct) Write(p []byte) (n int, err error) {
    fmt.Fprintf(os.Stdout, "%s", string(p))
    return len(p), nil
}

func demoLoadingBarCount(maximumInt int) {
    buf := tmpStruct{}
    if nBuf, ok := interface{}(&buf).(io.Writer); ok {
        bar := progressbar.NewOptions(
            maximumInt,
            progressbar.OptionSetTheme(progressbar.Theme{Saucer: "█", SaucerPadding: "-", BarStart: ">", BarEnd: "<"}),
            progressbar.OptionSetWidth(100),
            progressbar.OptionSetWriter(nBuf),
        )
        for i := 0; i < maximumInt; i++ {
            bar.Add(1)
            time.Sleep(10 * time.Millisecond)
        }
    }
}

All works, except there is no new line at the end as you can see here

I can't add a new line character in the Write function as that will cause it to new line after every byte pushed to the writer. Is there a neat way can I do this?

EDIT: I want the new line after the progress bar and before the next line prints out

Answer 1

The simple answer to the question you've asked is simply to print an additional newline after the progress bar is complete:

func demoLoadingBarCount(maximumInt int) {
    buf := &tmpStruct{}
    bar := progressbar.NewOptions(
        maximumInt,
        progressbar.OptionSetTheme(progressbar.Theme{Saucer: "█", SaucerPadding: "-", BarStart: ">", BarEnd: "<"}),
        progressbar.OptionSetWidth(100),
        progressbar.OptionSetWriter(buf),
    )
    for i := 0; i < maximumInt; i++ {
        bar.Add(1)
        time.Sleep(10 * time.Millisecond)
    }
    fmt.Fprintf(buf, "\n") // <---- Add this
}

Although your comments indicate that this is problematic, but you haven't explained how. If you update your question to explain why this is a problem, perhaps a better solution can follow.