184
184
.. _testrepository: https://launchpad.net/testrepository
187
Babune continuous integration
188
-----------------------------
190
We have a Hudson continuous-integration system that automatically runs
191
tests across various platforms. In the future we plan to add more
192
combinations including testing plugins. See
193
<http://babune.ladeuil.net:24842/>. (Babune = Bazaar Buildbot Network.)
196
Running tests in parallel
197
-------------------------
199
Bazaar can use subunit to spawn multiple test processes. There is
200
slightly more chance you will hit ordering or timing-dependent bugs but
203
$ ./bzr selftest --parallel=fork
205
Note that you will need the Subunit library
206
<https://launchpad.net/subunit/> to use this, which is in
207
``python-subunit`` on Ubuntu.
210
Running tests from a ramdisk
211
----------------------------
213
The tests create and delete a lot of temporary files. In some cases you
214
can make the test suite run much faster by running it on a ramdisk. For
218
$ sudo mount -t tmpfs none /ram
219
$ TMPDIR=/ram ./bzr selftest ...
221
You could also change ``/tmp`` in ``/etc/fstab`` to have type ``tmpfs``,
222
if you don't mind possibly losing other files in there when the machine
223
restarts. Add this line (if there is none for ``/tmp`` already)::
225
none /tmp tmpfs defaults 0 0
227
With a 6-core machine and ``--parallel=fork`` using a tmpfs doubles the
228
test execution speed.
329
284
We make selective use of doctests__. In general they should provide
330
285
*examples* within the API documentation which can incidentally be tested. We
331
286
don't try to test every important case using doctests |--| regular Python
332
tests are generally a better solution. That is, we just use doctests to make
333
our documentation testable, rather than as a way to make tests. Be aware that
334
doctests are not as well isolated as the unit tests, if you need more
335
isolation, you're likely want to write unit tests anyway if only to get a
336
better control of the test environment.
287
tests are generally a better solution. That is, we just use doctests to
288
make our documentation testable, rather than as a way to make tests.
338
290
Most of these are in ``bzrlib/doc/api``. More additions are welcome.
440
You can run files containing shell-like scripts with::
442
$ bzr test-script <script>
444
where ``<script>`` is the path to the file containing the shell-like script.
446
385
The actual use of ScriptRunner within a TestCase looks something like
449
from bzrlib.tests import script
451
def test_unshelve_keep(self):
453
script.run_script(self, '''
455
$ bzr shelve -q --all -m Foo
458
$ bzr unshelve -q --keep
465
You can also test commands that read user interaction::
467
def test_confirm_action(self):
468
"""You can write tests that demonstrate user confirmation"""
469
commands.builtin_command_registry.register(cmd_test_confirm)
470
self.addCleanup(commands.builtin_command_registry.remove, 'test-confirm')
473
2>Really do it? [y/n]:
478
To avoid having to specify "-q" for all commands whose output is
479
irrelevant, the run_script() method may be passed the keyword argument
480
``null_output_matches_anything=True``. For example::
482
def test_ignoring_null_output(self):
485
$ bzr ci -m 'first revision' --unchanged
488
""", null_output_matches_anything=True)
388
def test_unshelve_keep(self):
391
sr.run_script(self, '''
393
$ bzr shelve --all -m Foo
396
$ bzr unshelve --keep
491
404
Import tariff tests
492
405
-------------------
834
731
whether a test should be added for that particular implementation,
835
732
or for all implementations of the interface.
734
The multiplication of tests for different implementations is normally
735
accomplished by overriding the ``load_tests`` function used to load tests
736
from a module. This function typically loads all the tests, then applies
737
a TestProviderAdapter to them, which generates a longer suite containing
738
all the test variations.
837
740
See also `Per-implementation tests`_ (above).
840
Test scenarios and variations
841
-----------------------------
843
746
Some utilities are provided for generating variations of tests. This can
844
747
be used for per-implementation tests, or other cases where the same test
849
752
values to which the test should be applied. The test suite should then
850
753
also provide a list of scenarios in which to run the tests.
852
A single *scenario* is defined by a `(name, parameter_dict)` tuple. The
853
short string name is combined with the name of the test method to form the
854
test instance name. The parameter dict is merged into the instance's
859
load_tests = load_tests_apply_scenarios
861
class TestCheckout(TestCase):
863
scenarios = multiply_scenarios(
864
VaryByRepositoryFormat(),
868
The `load_tests` declaration or definition should be near the top of the
869
file so its effect can be seen.
755
Typically ``multiply_tests_from_modules`` should be called from the test
756
module's ``load_tests`` function.
887
774
A base TestCase that extends the Python standard library's
888
TestCase in several ways. TestCase is build on
889
``testtools.TestCase``, which gives it support for more assertion
890
methods (e.g. ``assertContainsRe``), ``addCleanup``, and other
891
features (see its API docs for details). It also has a ``setUp`` that
892
makes sure that global state like registered hooks and loggers won't
893
interfere with your test. All tests should use this base class
894
(whether directly or via a subclass). Note that we are trying not to
895
add more assertions at this point, and instead to build up a library
896
of ``bzrlib.tests.matchers``.
775
TestCase in several ways. It adds more assertion methods (e.g.
776
``assertContainsRe``), ``addCleanup``, and other features (see its API
777
docs for details). It also has a ``setUp`` that makes sure that
778
global state like registered hooks and loggers won't interfere with
779
your test. All tests should use this base class (whether directly or
898
782
TestCaseWithMemoryTransport
899
783
Extends TestCase and adds methods like ``get_transport``,
972
856
Please see bzrlib.treebuilder for more details.
977
PreviewTrees are based on TreeTransforms. This means they can represent
978
virtually any state that a WorkingTree can have, including unversioned files.
979
They can be used to test the output of anything that produces TreeTransforms,
980
such as merge algorithms and revert. They can also be used to test anything
981
that takes arbitrary Trees as its input.
985
# Get an empty tree to base the transform on.
986
b = self.make_branch('.')
987
empty_tree = b.repository.revision_tree(_mod_revision.NULL_REVISION)
988
tt = TransformPreview(empty_tree)
989
self.addCleanup(tt.finalize)
990
# Empty trees don't have a root, so add it first.
991
root = tt.new_directory('', ROOT_PARENT, 'tree-root')
992
# Set the contents of a file.
993
tt.new_file('new-file', root, 'contents', 'file-id')
994
preview = tt.get_preview_tree()
996
self.assertEqual('contents', preview.get_file_text('file-id'))
998
PreviewTrees can stack, with each tree falling back to the previous::
1000
tt2 = TransformPreview(preview)
1001
self.addCleanup(tt2.finalize)
1002
tt2.new_file('new-file2', tt2.root, 'contents2', 'file-id2')
1003
preview2 = tt2.get_preview_tree()
1004
self.assertEqual('contents', preview2.get_file_text('file-id'))
1005
self.assertEqual('contents2', preview2.get_file_text('file-id2'))
1008
Temporarily changing state
1009
~~~~~~~~~~~~~~~~~~~~~~~~~~
1011
If your test needs to temporarily mutate some global state, and you need
1012
it restored at the end, you can say for example::
1014
self.overrideAttr(osutils, '_cached_user_encoding', 'latin-1')
1016
Temporarily changing environment variables
1017
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1019
If yout test needs to temporarily change some environment variable value
1020
(which generally means you want it restored at the end), you can use::
1022
self.overrideEnv('BZR_ENV_VAR', 'new_value')
1024
If you want to remove a variable from the environment, you should use the
1025
special ``None`` value::
1027
self.overrideEnv('PATH', None)
1029
If you add a new feature which depends on a new environment variable, make
1030
sure it behaves properly when this variable is not defined (if applicable) and
1031
if you need to enforce a specific default value, check the
1032
``TestCase._cleanEnvironment`` in ``bzrlib.tests.__init__.py`` which defines a
1033
proper set of values for all tests.
1038
Our base ``TestCase`` class provides an ``addCleanup`` method, which
1039
should be used instead of ``tearDown``. All the cleanups are run when the
1040
test finishes, regardless of whether it passes or fails. If one cleanup
1041
fails, later cleanups are still run.
1043
(The same facility is available outside of tests through
1044
``bzrlib.cleanup``.)
1050
Generally we prefer automated testing but sometimes a manual test is the
1051
right thing, especially for performance tests that want to measure elapsed
1052
time rather than effort.
1054
Simulating slow networks
1055
------------------------
1057
To get realistically slow network performance for manually measuring
1058
performance, we can simulate 500ms latency (thus 1000ms round trips)::
1060
$ sudo tc qdisc add dev lo root netem delay 500ms
1062
Normal system behaviour is restored with ::
1064
$ sudo tc qdisc del dev lo root
1066
A more precise version that only filters traffic to port 4155 is::
1068
tc qdisc add dev lo root handle 1: prio
1069
tc qdisc add dev lo parent 1:3 handle 30: netem delay 500ms
1070
tc qdisc add dev lo parent 30:1 handle 40: prio
1071
tc filter add dev lo protocol ip parent 1:0 prio 3 u32 match ip dport 4155 0xffff flowid 1:3 handle 800::800
1072
tc filter add dev lo protocol ip parent 1:0 prio 3 u32 match ip sport 4155 0xffff flowid 1:3 handle 800::801
1074
and to remove this::
1076
tc filter del dev lo protocol ip parent 1: pref 3 u32
1077
tc qdisc del dev lo root handle 1:
1079
You can use similar code to add additional delay to a real network
1080
interface, perhaps only when talking to a particular server or pointing at
1081
a VM. For more information see <http://lartc.org/>.
1084
859
.. |--| unicode:: U+2014
1087
vim: ft=rst tw=74 ai et sw=4
added
removed
doc/developers/testing.txt
