Test Runner
===========

Errors and Failures
-------------------

Let's look at tests that have errors and failures:

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

    >>> sys.argv = 'test --tests-pattern ^sampletests(f|_e|_f)?$ '.split()
    >>> testrunner.run(defaults)
    ... # doctest: +NORMALIZE_WHITESPACE
    Running unit tests:
    <BLANKLINE>
    <BLANKLINE>
    Failure in test eek (sample2.sampletests_e)
    Failed doctest test for sample2.sampletests_e.eek
      File "testrunner-ex/sample2/sampletests_e.py", line 28, in eek
    <BLANKLINE>
    ----------------------------------------------------------------------
    File "testrunner-ex/sample2/sampletests_e.py", line 30, in sample2.sampletests_e.eek
    Failed example:
        f()
    Exception raised:
        Traceback (most recent call last):
          File ".../doctest.py", line 1256, in __run
            compileflags, 1) in test.globs
          File "<doctest sample2.sampletests_e.eek[0]>", line 1, in ?
            f()
          File "testrunner-ex/sample2/sampletests_e.py", line 19, in f
            g()
          File "testrunner-ex/sample2/sampletests_e.py", line 24, in g
            x = y + 1
        NameError: global name 'y' is not defined
    <BLANKLINE>
    <BLANKLINE>
    <BLANKLINE>
    Error in test test3 (sample2.sampletests_e.Test)
    Traceback (most recent call last):
      File "testrunner-ex/sample2/sampletests_e.py", line 43, in test3
        f()
      File "testrunner-ex/sample2/sampletests_e.py", line 19, in f
        g()
      File "testrunner-ex/sample2/sampletests_e.py", line 24, in g
        x = y + 1
    NameError: global name 'y' is not defined
    <BLANKLINE>
    <BLANKLINE>
    <BLANKLINE>
    Failure in test testrunner-ex/sample2/e.txt
    Failed doctest test for e.txt
      File "testrunner-ex/sample2/e.txt", line 0
    <BLANKLINE>
    ----------------------------------------------------------------------
    File "testrunner-ex/sample2/e.txt", line 4, in e.txt
    Failed example:
        f()
    Exception raised:
        Traceback (most recent call last):
          File ".../doctest.py", line 1256, in __run
            compileflags, 1) in test.globs
          File "<doctest e.txt[1]>", line 1, in ?
            f()
          File "<doctest e.txt[0]>", line 2, in f
            return x
        NameError: global name 'x' is not defined
    <BLANKLINE>
    <BLANKLINE>
    <BLANKLINE>
    Failure in test test (sample2.sampletests_f.Test)
    Traceback (most recent call last):
      File "testrunner-ex/sample2/sampletests_f.py", line 21, in test
        self.assertEqual(1,0)
      File "/usr/local/python/2.3/lib/python2.3/unittest.py", line 302, in failUnlessEqual
        raise self.failureException, \
    AssertionError: 1 != 0
    <BLANKLINE>
      Ran 200 tests with 3 failures and 1 errors in 0.038 seconds.
    Running samplelayers.Layer1 tests:
      Set up samplelayers.Layer1 in 0.000 seconds.
      Ran 9 tests with 0 failures and 0 errors in 0.000 seconds.
    Running samplelayers.Layer11 tests:
      Set up samplelayers.Layer11 in 0.000 seconds.
      Ran 34 tests with 0 failures and 0 errors in 0.007 seconds.
    Running samplelayers.Layer111 tests:
      Set up samplelayers.Layerx in 0.000 seconds.
      Set up samplelayers.Layer111 in 0.000 seconds.
      Ran 34 tests with 0 failures and 0 errors in 0.007 seconds.
    Running samplelayers.Layer112 tests:
      Tear down samplelayers.Layer111 in 0.000 seconds.
      Set up samplelayers.Layer112 in 0.000 seconds.
      Ran 34 tests with 0 failures and 0 errors in 0.006 seconds.
    Running samplelayers.Layer12 tests:
      Tear down samplelayers.Layer112 in 0.000 seconds.
      Tear down samplelayers.Layerx in 0.000 seconds.
      Tear down samplelayers.Layer11 in 0.000 seconds.
      Set up samplelayers.Layer12 in 0.000 seconds.
      Ran 34 tests with 0 failures and 0 errors in 0.007 seconds.
    Running samplelayers.Layer121 tests:
      Set up samplelayers.Layer121 in 0.000 seconds.
      Ran 34 tests with 0 failures and 0 errors in 0.006 seconds.
    Running samplelayers.Layer122 tests:
      Tear down samplelayers.Layer121 in 0.000 seconds.
      Set up samplelayers.Layer122 in 0.000 seconds.
      Ran 34 tests with 0 failures and 0 errors in 0.007 seconds.
    Tearing down left over layers:
      Tear down samplelayers.Layer122 in 0.000 seconds.
      Tear down samplelayers.Layer12 in 0.000 seconds.
      Tear down samplelayers.Layer1 in 0.000 seconds.
    Total: 413 tests, 3 failures, 1 errors
    True

We see that we get an error report and a traceback for the failing
test.  In addition, the test runner returned True, indicating that
there was an error.

If we ask for single verbosity, the dotted output will be interrupted:

    >>> sys.argv = 'test --tests-pattern ^sampletests(f|_e|_f)?$ -uv'.split()
    >>> testrunner.run(defaults)
    ... # doctest: +NORMALIZE_WHITESPACE +REPORT_NDIFF
    Running tests at level 1
    Running unit tests:
      Running:
     .................................................................................................
    <BLANKLINE>
    Failure in test eek (sample2.sampletests_e)
    Failed doctest test for sample2.sampletests_e.eek
      File "testrunner-ex/sample2/sampletests_e.py", line 28, in eek
    <BLANKLINE>
    ----------------------------------------------------------------------
    File "testrunner-ex/sample2/sampletests_e.py", line 30,
        in sample2.sampletests_e.eek
    Failed example:
        f()
    Exception raised:
        Traceback (most recent call last):
          File ".../doctest.py", line 1256, in __run
            compileflags, 1) in test.globs
          File "<doctest sample2.sampletests_e.eek[0]>", line 1, in ?
            f()
          File "testrunner-ex/sample2/sampletests_e.py", line 19, in f
            g()
          File "testrunner-ex/sample2/sampletests_e.py", line 24, in g
            x = y + 1
        NameError: global name 'y' is not defined
    <BLANKLINE>
    ...
    <BLANKLINE>
    <BLANKLINE>
    Error in test test3 (sample2.sampletests_e.Test)
    Traceback (most recent call last):
      File "testrunner-ex/sample2/sampletests_e.py", line 43, in test3
        f()
      File "testrunner-ex/sample2/sampletests_e.py", line 19, in f
        g()
      File "testrunner-ex/sample2/sampletests_e.py", line 24, in g
        x = y + 1
    NameError: global name 'y' is not defined
    <BLANKLINE>
    ...
    <BLANKLINE>
    Failure in test testrunner-ex/sample2/e.txt
    Failed doctest test for e.txt
      File "testrunner-ex/sample2/e.txt", line 0
    <BLANKLINE>
    ----------------------------------------------------------------------
    File "testrunner-ex/sample2/e.txt", line 4, in e.txt
    Failed example:
        f()
    Exception raised:
        Traceback (most recent call last):
          File ".../doctest.py", line 1256, in __run
            compileflags, 1) in test.globs
          File "<doctest e.txt[1]>", line 1, in ?
            f()
          File "<doctest e.txt[0]>", line 2, in f
            return x
        NameError: global name 'x' is not defined
    <BLANKLINE>
    .
    <BLANKLINE>
    Failure in test test (sample2.sampletests_f.Test)
    Traceback (most recent call last):
      File "testrunner-ex/sample2/sampletests_f.py", line 21, in test
        self.assertEqual(1,0)
      File ".../unittest.py", line 302, in failUnlessEqual
        raise self.failureException, \
    AssertionError: 1 != 0
    <BLANKLINE>
    ................................................................................................
    <BLANKLINE>
      Ran 200 tests with 3 failures and 1 errors in 0.040 seconds.
    True

Similarly for progress output:

    >>> sys.argv = ('test --tests-pattern ^sampletests(f|_e|_f)?$ -u -ssample2'
    ...             ' -p').split()
    >>> testrunner.run(defaults)
    ... # doctest: +NORMALIZE_WHITESPACE +REPORT_NDIFF
    Running unit tests:
      Running:
        1/56 (1.8%)
    <BLANKLINE>
    Failure in test eek (sample2.sampletests_e)
    Failed doctest test for sample2.sampletests_e.eek
      File "testrunner-ex/sample2/sampletests_e.py", line 28, in eek
    <BLANKLINE>
    ----------------------------------------------------------------------
    File "testrunner-ex/sample2/sampletests_e.py", line 30,
           in sample2.sampletests_e.eek
    Failed example:
        f()
    Exception raised:
        Traceback (most recent call last):
          File ".../doctest.py", line 1256, in __run
            compileflags, 1) in test.globs
          File "<doctest sample2.sampletests_e.eek[0]>", line 1, in ?
            f()
          File "testrunner-ex/sample2/sampletests_e.py", line 19, in f
            g()
          File "testrunner-ex/sample2/sampletests_e.py", line 24, in g
            x = y + 1
        NameError: global name 'y' is not defined
    <BLANKLINE>
        2/56 (3.6%)\r
                   \r
        3/56 (5.4%)\r
                   \r
        4/56 (7.1%)
    <BLANKLINE>
    Error in test test3 (sample2.sampletests_e.Test)
    Traceback (most recent call last):
      File "testrunner-ex/sample2/sampletests_e.py", line 43, in test3
        f()
      File "testrunner-ex/sample2/sampletests_e.py", line 19, in f
        g()
      File "testrunner-ex/sample2/sampletests_e.py", line 24, in g
        x = y + 1
    NameError: global name 'y' is not defined
    <BLANKLINE>
        5/56 (8.9%)\r
                   \r
        6/56 (10.7%)\r
                    \r
        7/56 (12.5%)
    <BLANKLINE>
    Failure in test testrunner-ex/sample2/e.txt
    Failed doctest test for e.txt
      File "testrunner-ex/sample2/e.txt", line 0
    <BLANKLINE>
    ----------------------------------------------------------------------
    File "testrunner-ex/sample2/e.txt", line 4, in e.txt
    Failed example:
        f()
    Exception raised:
        Traceback (most recent call last):
          File ".../doctest.py", line 1256, in __run
            compileflags, 1) in test.globs
          File "<doctest e.txt[1]>", line 1, in ?
            f()
          File "<doctest e.txt[0]>", line 2, in f
            return x
        NameError: global name 'x' is not defined
    <BLANKLINE>
        8/56 (14.3%)
    <BLANKLINE>
    Failure in test test (sample2.sampletests_f.Test)
    Traceback (most recent call last):
      File "testrunner-ex/sample2/sampletests_f.py", line 21, in test
        self.assertEqual(1,0)
      File ".../unittest.py", line 302, in failUnlessEqual
        raise self.failureException, \
    AssertionError: 1 != 0
    <BLANKLINE>
        9/56 (16.1%)\r
                    \r
        10/56 (17.9%)\r
                     \r
        11/56 (19.6%)\r
                     \r
        12/56 (21.4%)\r
                     \r
        13/56 (23.2%)\r
                     \r
        14/56 (25.0%)\r
                     \r
        15/56 (26.8%)\r
                     \r
        16/56 (28.6%)\r
                     \r
        17/56 (30.4%)\r
                     \r
        18/56 (32.1%)\r
                     \r
        19/56 (33.9%)\r
                     \r
        20/56 (35.7%)\r
                     \r
        24/56 (42.9%)\r
                     \r
        25/56 (44.6%)\r
                     \r
        26/56 (46.4%)\r
                     \r
        27/56 (48.2%)\r
                     \r
        28/56 (50.0%)\r
                     \r
        29/56 (51.8%)\r
                     \r
        30/56 (53.6%)\r
                     \r
        31/56 (55.4%)\r
                     \r
        32/56 (57.1%)\r
                     \r
        33/56 (58.9%)\r
                     \r
        34/56 (60.7%)\r
                     \r
        35/56 (62.5%)\r
                     \r
        36/56 (64.3%)\r
                     \r
        40/56 (71.4%)\r
                     \r
        41/56 (73.2%)\r
                     \r
        42/56 (75.0%)\r
                     \r
        43/56 (76.8%)\r
                     \r
        44/56 (78.6%)\r
                     \r
        45/56 (80.4%)\r
                     \r
        46/56 (82.1%)\r
                     \r
        47/56 (83.9%)\r
                     \r
        48/56 (85.7%)\r
                     \r
        49/56 (87.5%)\r
                     \r
        50/56 (89.3%)\r
                     \r
        51/56 (91.1%)\r
                     \r
        52/56 (92.9%)\r
                     \r
        56/56 (100.0%)\r
                      \r
    <BLANKLINE>
      Ran 56 tests with 3 failures and 1 errors in 0.054 seconds.
    True

For greater levels of verbosity, we summarize the errors at the end of
the test

    >>> sys.argv = ('test --tests-pattern ^sampletests(f|_e|_f)?$ -u -ssample2'
    ...             ' -vv').split()
    >>> testrunner.run(defaults)
    ... # doctest: +NORMALIZE_WHITESPACE
    Running tests at level 1
    Running unit tests:
      Running:
        eek (sample2.sampletests_e)
    <BLANKLINE>
    Failure in test eek (sample2.sampletests_e)
    Failed doctest test for sample2.sampletests_e.eek
      File "testrunner-ex/sample2/sampletests_e.py", line 28, in eek
    <BLANKLINE>
    ----------------------------------------------------------------------
    File "testrunner-ex/sample2/sampletests_e.py", line 30,
           in sample2.sampletests_e.eek
    Failed example:
        f()
    Exception raised:
        Traceback (most recent call last):
          File ".../doctest.py", line 1256, in __run
            compileflags, 1) in test.globs
          File "<doctest sample2.sampletests_e.eek[0]>", line 1, in ?
            f()
          File "testrunner-ex/sample2/sampletests_e.py", line 19, in f
            g()
          File "testrunner-ex/sample2/sampletests_e.py", line 24, in g
            x = y + 1
        NameError: global name 'y' is not defined
    <BLANKLINE>
    <BLANKLINE>
        test1 (sample2.sampletests_e.Test)
        test2 (sample2.sampletests_e.Test)
        test3 (sample2.sampletests_e.Test)
    <BLANKLINE>
    Error in test test3 (sample2.sampletests_e.Test)
    Traceback (most recent call last):
      File "testrunner-ex/sample2/sampletests_e.py", line 43, in test3
        f()
      File "testrunner-ex/sample2/sampletests_e.py", line 19, in f
        g()
      File "testrunner-ex/sample2/sampletests_e.py", line 24, in g
        x = y + 1
    NameError: global name 'y' is not defined
    <BLANKLINE>
    <BLANKLINE>
        test4 (sample2.sampletests_e.Test)
        test5 (sample2.sampletests_e.Test)
        testrunner-ex/sample2/e.txt
    <BLANKLINE>
    Failure in test testrunner-ex/sample2/e.txt
    Failed doctest test for e.txt
      File "testrunner-ex/sample2/e.txt", line 0
    <BLANKLINE>
    ----------------------------------------------------------------------
    File "testrunner-ex/sample2/e.txt", line 4, in e.txt
    Failed example:
        f()
    Exception raised:
        Traceback (most recent call last):
          File ".../doctest.py", line 1256, in __run
            compileflags, 1) in test.globs
          File "<doctest e.txt[1]>", line 1, in ?
            f()
          File "<doctest e.txt[0]>", line 2, in f
            return x
        NameError: global name 'x' is not defined
    <BLANKLINE>
    <BLANKLINE>
        test (sample2.sampletests_f.Test)
    <BLANKLINE>
    Failure in test test (sample2.sampletests_f.Test)
    Traceback (most recent call last):
      File "testrunner-ex/sample2/sampletests_f.py", line 21, in test
        self.assertEqual(1,0)
      File ".../unittest.py", line 302, in failUnlessEqual
        raise self.failureException, \
    AssertionError: 1 != 0
    <BLANKLINE>
    <BLANKLINE>
        test_x1 (sample2.sample21.sampletests.TestA)
        test_y0 (sample2.sample21.sampletests.TestA)
        test_z0 (sample2.sample21.sampletests.TestA)
        test_x0 (sample2.sample21.sampletests.TestB)
        test_y1 (sample2.sample21.sampletests.TestB)
        test_z0 (sample2.sample21.sampletests.TestB)
        test_1 (sample2.sample21.sampletests.TestNotMuch)
        test_2 (sample2.sample21.sampletests.TestNotMuch)
        test_3 (sample2.sample21.sampletests.TestNotMuch)
        test_x0 (sample2.sample21.sampletests)
        test_y0 (sample2.sample21.sampletests)
        test_z1 (sample2.sample21.sampletests)
        testrunner-ex/sample2/sample21/../../sampletests.txt
        test_x1 (sample2.sampletests.test_1.TestA)
        test_y0 (sample2.sampletests.test_1.TestA)
        test_z0 (sample2.sampletests.test_1.TestA)
        test_x0 (sample2.sampletests.test_1.TestB)
        test_y1 (sample2.sampletests.test_1.TestB)
        test_z0 (sample2.sampletests.test_1.TestB)
        test_1 (sample2.sampletests.test_1.TestNotMuch)
        test_2 (sample2.sampletests.test_1.TestNotMuch)
        test_3 (sample2.sampletests.test_1.TestNotMuch)
        test_x0 (sample2.sampletests.test_1)
        test_y0 (sample2.sampletests.test_1)
        test_z1 (sample2.sampletests.test_1)
        testrunner-ex/sample2/sampletests/../../sampletests.txt
        test_x1 (sample2.sampletests.testone.TestA)
        test_y0 (sample2.sampletests.testone.TestA)
        test_z0 (sample2.sampletests.testone.TestA)
        test_x0 (sample2.sampletests.testone.TestB)
        test_y1 (sample2.sampletests.testone.TestB)
        test_z0 (sample2.sampletests.testone.TestB)
        test_1 (sample2.sampletests.testone.TestNotMuch)
        test_2 (sample2.sampletests.testone.TestNotMuch)
        test_3 (sample2.sampletests.testone.TestNotMuch)
        test_x0 (sample2.sampletests.testone)
        test_y0 (sample2.sampletests.testone)
        test_z1 (sample2.sampletests.testone)
        testrunner-ex/sample2/sampletests/../../sampletests.txt
      Ran 56 tests with 3 failures and 1 errors in 0.060 seconds.
    <BLANKLINE>
    Tests with errors:
       test3 (sample2.sampletests_e.Test)
    <BLANKLINE>
    Tests with failures:
       eek (sample2.sampletests_e)
       testrunner-ex/sample2/e.txt
       test (sample2.sampletests_f.Test)
    True

Suppressing multiple doctest errors
-----------------------------------

Often, when a doctest example fails, the failure will cause later
examples in the same test to fail.  Each failure is reported:

    >>> sys.argv = 'test --tests-pattern ^sampletests_1$'.split()
    >>> testrunner.run(defaults) # doctest: +NORMALIZE_WHITESPACE
    Running unit tests:
    <BLANKLINE>
    <BLANKLINE>
    Failure in test eek (sample2.sampletests_1)
    Failed doctest test for sample2.sampletests_1.eek
      File "testrunner-ex/sample2/sampletests_1.py", line 17, in eek
    <BLANKLINE>
    ----------------------------------------------------------------------
    File "testrunner-ex/sample2/sampletests_1.py", line 19,
         in sample2.sampletests_1.eek
    Failed example:
        x = y
    Exception raised:
        Traceback (most recent call last):
          File ".../doctest.py", line 1256, in __run
            compileflags, 1) in test.globs
          File "<doctest sample2.sampletests_1.eek[0]>", line 1, in ?
            x = y
        NameError: name 'y' is not defined
    ----------------------------------------------------------------------
    File "testrunner-ex/sample2/sampletests_1.py", line 21,
         in sample2.sampletests_1.eek
    Failed example:
        x
    Exception raised:
        Traceback (most recent call last):
          File ".../doctest.py", line 1256, in __run
            compileflags, 1) in test.globs
          File "<doctest sample2.sampletests_1.eek[1]>", line 1, in ?
            x
        NameError: name 'x' is not defined
    ----------------------------------------------------------------------
    File "testrunner-ex/sample2/sampletests_1.py", line 24,
         in sample2.sampletests_1.eek
    Failed example:
        z = x + 1
    Exception raised:
        Traceback (most recent call last):
          File ".../doctest.py", line 1256, in __run
            compileflags, 1) in test.globs
          File "<doctest sample2.sampletests_1.eek[2]>", line 1, in ?
            z = x + 1
        NameError: name 'x' is not defined
    <BLANKLINE>
      Ran 1 tests with 1 failures and 0 errors in 0.002 seconds.
    True

This can be a bit confusing, especially when there are enough tests
that they scroll off a screen.  Often you just want to see the first
failure.  This can be accomplished with the -1 option (for "just show
me the first failed example in a doctest" :)

    >>> sys.argv = 'test --tests-pattern ^sampletests_1$ -1'.split()
    >>> testrunner.run(defaults) # doctest:
    Running unit tests:
    <BLANKLINE>
    <BLANKLINE>
    Failure in test eek (sample2.sampletests_1)
    Failed doctest test for sample2.sampletests_1.eek
      File "testrunner-ex/sample2/sampletests_1.py", line 17, in eek
    <BLANKLINE>
    ----------------------------------------------------------------------
    File "testrunner-ex/sample2/sampletests_1.py", line 19,
         in sample2.sampletests_1.eek
    Failed example:
        x = y
    Exception raised:
        Traceback (most recent call last):
          File ".../doctest.py", line 1256, in __run
            compileflags, 1) in test.globs
          File "<doctest sample2.sampletests_1.eek[0]>", line 1, in ?
            x = y
        NameError: name 'y' is not defined
    <BLANKLINE>
      Ran 1 tests with 1 failures and 0 errors in 0.001 seconds.
    True

Getting diff output for doctest failures
----------------------------------------

If a doctest has large expected and actual output, it can be hard to
see differences when expected and actual output differ.  The --ndiff,
--udiff, and --cdiff options can be used to get diff output pf various
kinds.

    >>> sys.argv = 'test --tests-pattern ^pledge$'.split()
    >>> _ = testrunner.run(defaults)
    Running unit tests:
    <BLANKLINE>
    <BLANKLINE>
    Failure in test pledge (pledge)
    Failed doctest test for pledge.pledge
      File "testrunner-ex/pledge.py", line 24, in pledge
    <BLANKLINE>
    ----------------------------------------------------------------------
    File "testrunner-ex/pledge.py", line 26, in pledge.pledge
    Failed example:
        print pledge_template % ('and earthling', 'planet'),
    Expected:
        I give my pledge, as an earthling,
        to save, and faithfully, to defend from waste,
        the natural resources of my planet.
        It's soils, minerals, forests, waters, and wildlife.
    Got:
        I give my pledge, as and earthling,
        to save, and faithfully, to defend from waste,
        the natural resources of my planet.
        It's soils, minerals, forests, waters, and wildlife.
    <BLANKLINE>
      Ran 1 tests with 1 failures and 0 errors in 0.002 seconds.

Here, the actual output uses the word "and" rather than the word "an",
but it's a bit hard to pick this out.  Wr can use the various diff
outputs to see this better. We could modify the test to ask for diff
output, but it's easier to use one of the diff options.

The --ndiff option requests a diff using Python's ndiff utility. This
is the only method that marks differences within lines as well as
across lines. For example, if a line of expected output contains digit
1 where actual output contains letter l, a line is inserted with a
caret marking the mismatching column positions.

    >>> sys.argv = 'test --tests-pattern ^pledge$ --ndiff'.split()
    >>> _ = testrunner.run(defaults)
    Running unit tests:
    <BLANKLINE>
    <BLANKLINE>
    Failure in test pledge (pledge)
    Failed doctest test for pledge.pledge
      File "testrunner-ex/pledge.py", line 24, in pledge
    <BLANKLINE>
    ----------------------------------------------------------------------
    File "testrunner-ex/pledge.py", line 26, in pledge.pledge
    Failed example:
        print pledge_template % ('and earthling', 'planet'),
    Differences (ndiff with -expected +actual):
        - I give my pledge, as an earthling,
        + I give my pledge, as and earthling,
        ?                        +
          to save, and faithfully, to defend from waste,
          the natural resources of my planet.
          It's soils, minerals, forests, waters, and wildlife.
    <BLANKLINE>
      Ran 1 tests with 1 failures and 0 errors in 0.003 seconds.

The -udiff option requests a standard "unified" diff:

    >>> sys.argv = 'test --tests-pattern ^pledge$ --udiff'.split()
    >>> _ = testrunner.run(defaults)
    Running unit tests:
    <BLANKLINE>
    <BLANKLINE>
    Failure in test pledge (pledge)
    Failed doctest test for pledge.pledge
      File "testrunner-ex/pledge.py", line 24, in pledge
    <BLANKLINE>
    ----------------------------------------------------------------------
    File "testrunner-ex/pledge.py", line 26, in pledge.pledge
    Failed example:
        print pledge_template % ('and earthling', 'planet'),
    Differences (unified diff with -expected +actual):
        @@ -1,3 +1,3 @@
        -I give my pledge, as an earthling,
        +I give my pledge, as and earthling,
         to save, and faithfully, to defend from waste,
         the natural resources of my planet.
    <BLANKLINE>
      Ran 1 tests with 1 failures and 0 errors in 0.002 seconds.

The -cdiff option requests a standard "context" diff:

    >>> sys.argv = 'test --tests-pattern ^pledge$ --cdiff'.split()
    >>> _ = testrunner.run(defaults)
    Running unit tests:
    <BLANKLINE>
    <BLANKLINE>
    Failure in test pledge (pledge)
    Failed doctest test for pledge.pledge
      File "testrunner-ex/pledge.py", line 24, in pledge
    <BLANKLINE>
    ----------------------------------------------------------------------
    File "testrunner-ex/pledge.py", line 26, in pledge.pledge
    Failed example:
        print pledge_template % ('and earthling', 'planet'),
    Differences (context diff with expected followed by actual):
        ***************
        *** 1,3 ****
        ! I give my pledge, as an earthling,
          to save, and faithfully, to defend from waste,
          the natural resources of my planet.
        --- 1,3 ----
        ! I give my pledge, as and earthling,
          to save, and faithfully, to defend from waste,
          the natural resources of my planet.
    <BLANKLINE>
      Ran 1 tests with 1 failures and 0 errors in 0.002 seconds.


Testing-Module Import Errors
----------------------------

If there are errors when importing a test module, these errors are
reported.  In order to illustrate a module with a syntax error, we create
one now:  this module used to be checked in to the project, but then it was
included in distributions of projects using zope.testing too, and distutils
complained about the syntax error when it compiled Python files during
installation of such projects.  So first we create a module with bad syntax:

    >>> badsyntax_path = os.path.join(directory_with_tests,
    ...                               "sample2", "sampletests_i.py")
    >>> f = open(badsyntax_path, "w")
    >>> print >> f, "importx unittest"  # syntax error
    >>> f.close()

Then run the tests:

    >>> sys.argv = ('test --tests-pattern ^sampletests(f|_i)?$ --layer 1 '
    ...            ).split()
    >>> testrunner.run(defaults)
    ... # doctest: +NORMALIZE_WHITESPACE
    Test-module import failures:
    <BLANKLINE>
    Module: sample2.sampletests_i
    <BLANKLINE>
      File "testrunner-ex/sample2/sampletests_i.py", line 1
        importx unittest
                       ^
    SyntaxError: invalid syntax
    <BLANKLINE>
    <BLANKLINE>
    Module: sample2.sample21.sampletests_i
    <BLANKLINE>
    Traceback (most recent call last):
      File "testrunner-ex/sample2/sample21/sampletests_i.py", line 15, in ?
        import zope.testing.huh
    ImportError: No module named huh
    <BLANKLINE>
    <BLANKLINE>
    Module: sample2.sample22.sampletests_i
    <BLANKLINE>
    AttributeError: 'module' object has no attribute 'test_suite'
    <BLANKLINE>
    <BLANKLINE>
    Module: sample2.sample23.sampletests_i
    <BLANKLINE>
    Traceback (most recent call last):
      File "testrunner-ex/sample2/sample23/sampletests_i.py", line 18, in ?
        class Test(unittest.TestCase):
      File "testrunner-ex/sample2/sample23/sampletests_i.py", line 23, in Test
        raise TypeError('eek')
    TypeError: eek
    <BLANKLINE>
    <BLANKLINE>
    Running samplelayers.Layer1 tests:
      Set up samplelayers.Layer1 in 0.000 seconds.
      Ran 9 tests with 0 failures and 0 errors in 0.000 seconds.
    Running samplelayers.Layer11 tests:
      Set up samplelayers.Layer11 in 0.000 seconds.
      Ran 34 tests with 0 failures and 0 errors in 0.007 seconds.
    Running samplelayers.Layer111 tests:
      Set up samplelayers.Layerx in 0.000 seconds.
      Set up samplelayers.Layer111 in 0.000 seconds.
      Ran 34 tests with 0 failures and 0 errors in 0.007 seconds.
    Running samplelayers.Layer112 tests:
      Tear down samplelayers.Layer111 in 0.000 seconds.
      Set up samplelayers.Layer112 in 0.000 seconds.
      Ran 34 tests with 0 failures and 0 errors in 0.007 seconds.
    Running samplelayers.Layer12 tests:
      Tear down samplelayers.Layer112 in 0.000 seconds.
      Tear down samplelayers.Layerx in 0.000 seconds.
      Tear down samplelayers.Layer11 in 0.000 seconds.
      Set up samplelayers.Layer12 in 0.000 seconds.
      Ran 34 tests with 0 failures and 0 errors in 0.007 seconds.
    Running samplelayers.Layer121 tests:
      Set up samplelayers.Layer121 in 0.000 seconds.
      Ran 34 tests with 0 failures and 0 errors in 0.007 seconds.
    Running samplelayers.Layer122 tests:
      Tear down samplelayers.Layer121 in 0.000 seconds.
      Set up samplelayers.Layer122 in 0.000 seconds.
      Ran 34 tests with 0 failures and 0 errors in 0.006 seconds.
    Tearing down left over layers:
      Tear down samplelayers.Layer122 in 0.000 seconds.
      Tear down samplelayers.Layer12 in 0.000 seconds.
      Tear down samplelayers.Layer1 in 0.000 seconds.
    Total: 213 tests, 0 failures, 0 errors
    <BLANKLINE>
    Test-modules with import problems:
      sample2.sampletests_i
      sample2.sample21.sampletests_i
      sample2.sample22.sampletests_i
      sample2.sample23.sampletests_i
    True

And remove the file with bad syntax:

    >>> os.remove(badsyntax_path)
