无法将切片附加到现有切片

My goal below is to return a slice of slices, so I can iterate over them later in my main function.

The current behavior is the "test" variable will show each line in a slice when I print it at fmt.PrintLn(test), but the "parsed" variable when printed at fmt.PrintLn(showParsed) is empty. How can I resolve that?

func lsCommand(outString string) []string {
    scanner := bufio.NewScanner(strings.NewReader(outString))
    var parsed []string
    for scanner.Scan() {
        s := scanner.Text()
        ss := strings.Fields(s)
        test := append(parsed, ss...)
        fmt.Println(test)
    }
    return parsed
}

func main() {
    ctx := context.Background()
    ok, outString, errString := runBashCommandAndKillIfTooSlow(ctx, "ls", 2000*time.Millisecond)
    if ok != true {
        panic(errString)
    }

    showParsed := lsCommand(outString)
    fmt.Println(showParsed)
}

append isn't guaranteed to modify the slice passed to it, so parsed isn't changed. Only test contains the elements of ss. Use the returned value in each iteration:

var parsed []string
for scanner.Scan() {
    s := scanner.Text()
    ss := strings.Fields(s)
    parsed = append(parsed, ss...)
}
return parsed