$ cat > loop.py <<EOF

  > from mercurial import commands

  > 

  > def loop(ui, loops, **opts):

  >     loops = int(loops)

  >     total = None

  >     if loops >= 0:

  >         total = loops

  >     if opts.get('total', None):

  >         total = int(opts.get('total'))

  >     loops = abs(loops)

  > 

  >     for i in range(loops):

  >         ui.progress('loop', i, 'loop.%d' % i, 'loopnum', total)

  >     ui.progress('loop', None, 'loop.done', 'loopnum', total)

  > 

  > commands.norepo += " loop"

  > 

  > cmdtable = {

  >     "loop": (loop, [('', 'total', '', 'override for total')],

  >              'hg loop LOOPS'),

  > }

  > EOF

  $ cat > filtercr.py <<EOF

  > import sys, re

  > for line in sys.stdin:

  >     line = re.sub(r'\r+[^\n]', lambda m: '\n' + m.group()[-1:], line)

  >     sys.stdout.write(line)

  > print

  > EOF

  $ echo "[extensions]" >> $HGRCPATH

  $ echo "progress=" >> $HGRCPATH

  $ echo "loop=`pwd`/loop.py" >> $HGRCPATH

  $ echo "[progress]" >> $HGRCPATH

  $ echo "assume-tty=1" >> $HGRCPATH

test default params, display nothing because of delay

  $ hg -y loop 3 2>&1 | python filtercr.py

  $ echo "delay=0" >> $HGRCPATH

  $ echo "refresh=0" >> $HGRCPATH

test with delay=0, refresh=0

  $ hg -y loop 3 2>&1 | python filtercr.py

  loop [                                                                    ] 0/3

  loop [=====================>                                              ] 1/3

  loop [============================================>                       ] 2/3

                                                                                  \r (esc)

test refresh is taken in account

  $ hg -y --config progress.refresh=100 loop 3 2>&1 | python filtercr.py

test format options 1

  $ hg -y --config 'progress.format=number topic item+2' loop 2 2>&1 | python filtercr.py

  0/2 loop lo

  1/2 loop lo

                                                                                  \r (esc)

test format options 2

  $ hg -y --config 'progress.format=number item-3 bar' loop 2 2>&1 | python filtercr.py

  0/2 p.0 [                                                                     ]

  1/2 p.1 [=================================>                                   ]

                                                                                  \r (esc)

test format options and indeterminate progress

  $ hg -y --config 'progress.format=number item bar' loop -- -2 2>&1 | python filtercr.py

  0 loop.0               [ <=>                                                  ]

  1 loop.1               [  <=>                                                 ]

                                                                                  \r (esc)

make sure things don't fall over if count > total

  $ hg -y loop --total 4 6 2>&1 | python filtercr.py

  loop [                                                                    ] 0/4

  loop [================>                                                   ] 1/4

  loop [=================================>                                  ] 2/4

  loop [==================================================>                 ] 3/4

  loop [===================================================================>] 4/4

  loop [ <=>                                                                ] 5/4

                                                                                  \r (esc)

test immediate progress completion

  $ hg -y loop 0 2>&1 | python filtercr.py