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"