Repeating Tests
===============

The --repeat option can be used to repeat tests some number of times.
Repeating tests is useful to help make sure that tests clean up after
themselves.

    >>> import os.path, sys
    >>> directory_with_tests = os.path.join(this_directory, 'testrunner-ex')
    >>> defaults = [
    ...     '--path', directory_with_tests,
    ...     '--tests-pattern', '^sampletestsf?$',
    ...     ]

    >>> sys.argv = 'test --layer 112 --layer UnitTests --repeat 3'.split()
    >>> from zope import testrunner
    >>> testrunner.run_internal(defaults)
    Running samplelayers.Layer112 tests:
      Set up samplelayers.Layerx in 0.000 seconds.
      Set up samplelayers.Layer1 in 0.000 seconds.
      Set up samplelayers.Layer11 in 0.000 seconds.
      Set up samplelayers.Layer112 in 0.000 seconds.
    Iteration 1
      Ran 26 tests with 0 failures, 0 errors and 0 skipped in 0.010 seconds.
    Iteration 2
      Ran 26 tests with 0 failures, 0 errors and 0 skipped in 0.010 seconds.
    Iteration 3
      Ran 26 tests with 0 failures, 0 errors and 0 skipped in 0.010 seconds.
    Running zope.testrunner.layer.UnitTests tests:
      Tear down samplelayers.Layer112 in N.NNN seconds.
      Tear down samplelayers.Layerx in N.NNN seconds.
      Tear down samplelayers.Layer11 in N.NNN seconds.
      Tear down samplelayers.Layer1 in N.NNN seconds.
      Set up zope.testrunner.layer.UnitTests in N.NNN seconds.
    Iteration 1
      Ran 156 tests with 0 failures, 0 errors and 0 skipped in N.NNN seconds.
    Iteration 2
      Ran 156 tests with 0 failures, 0 errors and 0 skipped in N.NNN seconds.
    Iteration 3
      Ran 156 tests with 0 failures, 0 errors and 0 skipped in N.NNN seconds.
    Tearing down left over layers:
      Tear down zope.testrunner.layer.UnitTests in N.NNN seconds.
    Total: 182 tests, 0 failures, 0 errors and 0 skipped in N.NNN seconds.
    False

The tests are repeated by layer.  Layers are set up and torn down only
once.