view tests/test-worker.t @ 31950:cc70c6dbac30

util: add a way to issue deprecation warning without a UI object

Our current deprecation warning mechanism relies on ui object. They are case
where we cannot have access to the UI object. On a general basis we avoid using
the python mechanism for deprecation warning because up to Python 2.6 it is
exposing warning to unsuspecting user who cannot do anything to deal with them.

So we build a "safe" strategy to hide this warnings behind a flag in an
environment variable. The test runner set this flag so that tests show these
warning.  This will help us marker API as deprecated for extensions to update
their code.

Test UI worker interaction

  $ cat > t.py <<EOF
  > from __future__ import absolute_import, print_function
  > from mercurial import (
  >     cmdutil,
  >     ui as uimod,
  >     worker,
  > )
  > def runme(ui, args):
  >     for arg in args:
  >         ui.status('run\n')
  >         yield 1, arg
  > cmdtable = {}
  > command = cmdutil.command(cmdtable)
  > @command('test', [], 'hg test [COST]')
  > def t(ui, repo, cost=1.0):
  >     cost = float(cost)
  >     ui.status('start\n')
  >     runs = worker.worker(ui, cost, runme, (ui,), range(8))
  >     for n, i in runs:
  >         pass
  >     ui.status('done\n')
  > EOF
  $ abspath=`pwd`/t.py
  $ hg init

Run tests with worker enable by forcing a heigh cost

  $ hg --config "extensions.t=$abspath" test 100000.0
  start
  run
  run
  run
  run
  run
  run
  run
  run
  done

Run tests without worker by forcing a low cost

  $ hg --config "extensions.t=$abspath" test 0.0000001
  start
  run
  run
  run
  run
  run
  run
  run
  run
  done