Move escape codes to Tty.

Library/Homebrew/cmd/fetch.rb

@@ -275,7 +275,7 @@ def run
 
  finished_downloads.each do |downloadable, future|
  previous_pending_line_count -= 1
- print "\033[K"
+ $stdout.print Tty.clear_to_end
  $stdout.flush
  output_message.call(downloadable, future)
  end
@@ -284,13 +284,13 @@ def run
  remaining_downloads.each do |downloadable, future|
  break if previous_pending_line_count >= [concurrency, (Tty.height - 1)].min
 
- print "\033[K"
+ $stdout.print Tty.clear_to_end
  $stdout.flush
  previous_pending_line_count += output_message.call(downloadable, future)
  end
 
  if previous_pending_line_count.positive?
- $stdout.print "\033[#{previous_pending_line_count}A"
+ $stdout.print Tty.move_cursor_up(previous_pending_line_count)
  $stdout.flush
  end
 
@@ -300,8 +300,11 @@ def run
  # FIXME: Implement cancellation of running downloads.
  end
 
- print "\n" * previous_pending_line_count
- $stdout.flush
+ if previous_pending_line_count.positive?
+ $stdout.print Tty.move_cursor_down(previous_pending_line_count - 1)
+ $stdout.flush
+ end
+
  raise
  end
  end

Library/Homebrew/utils/tty.rb

@@ -51,6 +51,21 @@ def strip_ansi(string)
  string.gsub(/\033\[\d+(;\d+)*m/, "")
  end
 
+ sig { params(line_count: Integer).returns(String) }
+ def move_cursor_up(line_count)
+ "\033[#{line_count}A"
+ end
+
+ sig { params(line_count: Integer).returns(String) }
+ def move_cursor_down(line_count)
+ "\033[#{line_count}B"
+ end
+
+ sig { returns(String) }
+ def clear_to_end
+ "\033[K"
+ end
+
  sig { returns(String) }
  def hide_cursor
  "\033[?25l"