dotsv2: remove jitters

internal/dotwriter/writer.go

@@ -31,11 +31,21 @@ func (w *Writer) Flush() error {
 		return nil
 	}
 	defer w.hideCursor()()
-	w.clearLines(w.lineCount)
-	w.lineCount = bytes.Count(w.buf.Bytes(), []byte{'\n'})
-	_, err := w.out.Write(w.buf.Bytes())
+	w.up(w.lineCount)
+
+	lines := bytes.Split(w.buf.Bytes(), []byte{'\n'})
+	w.lineCount = len(lines) - 1
+	for i, line := range lines {
+		w.out.Write(line)
+		w.clearRest()
+		if i != len(lines)-1 {
+			w.out.Write([]byte{'\n'})
+		} else {
+
+		}
+	}
 	w.buf.Reset()
-	return err
+	return nil
 }
 
 // Write saves buf to a buffer

internal/dotwriter/writer_posix.go

@@ -17,6 +17,17 @@ func (w *Writer) clearLines(count int) {
 	_, _ = fmt.Fprint(w.out, strings.Repeat(clear, count))
 }
 
+func (w *Writer) up(count int) {
+	if count == 0 {
+		return
+	}
+	_, _ = fmt.Fprint(w.out, fmt.Sprintf("%c[%dA", ESC, count))
+}
+
+func (w *Writer) clearRest() {
+	_, _ = fmt.Fprint(w.out, fmt.Sprintf("%c[0K", ESC))
+}
+
 // hideCursor hides the cursor and returns a function to restore the cursor back.
 func (w *Writer) hideCursor() func() {
 	_, _ = fmt.Fprint(w.out, hide)