39
39
Running the Test Suite
40
40
======================
42
As of Bazaar 2.1, you must have the testtools_ library installed to run
45
.. _testtools: https://launchpad.net/testtools/
47
To test all of Bazaar, just run::
51
With ``--verbose`` bzr will print the name of every test as it is run.
53
This should always pass, whether run from a source tree or an installed
54
copy of Bazaar. Please investigate and/or report any failures.
57
Running particular tests
58
------------------------
42
60
Currently, bzr selftest is used to invoke tests.
43
61
You can provide a pattern argument to run a subset. For example,
44
62
to run just the blackbox tests, run::
86
104
--load-list. The later is rarely used but allows to run a subset of a list of
87
105
failing tests for example.
110
To test only the bzr core, ignoring any plugins you may have installed,
113
./bzr --no-plugins selftest
115
Disabling crash reporting
116
-------------------------
118
By default Bazaar uses apport_ to report program crashes. In developing
119
Bazaar it's normal and expected to have it crash from time to time, at
120
least because a test failed if for no other reason.
122
Therefore you should probably add ``debug_flags = no_apport`` to your
123
``bazaar.conf`` file (in ``~/.bazaar/`` on Unix), so that failures just
124
print a traceback rather than writing a crash file.
126
.. _apport: https://launchpad.net/apport/
90
129
Test suite debug flags
91
130
----------------------
97
136
This can provide useful logging to help debug test failures when used
98
137
with e.g. ``bzr -Dhpss selftest -E=allow_debug``
139
Note that this will probably cause some tests to fail, because they
140
don't expect to run with any debug flags on.
146
Bazaar can optionally produce output in the machine-readable subunit_
147
format, so that test output can be post-processed by various tools. To
148
generate a subunit test stream::
150
$ ./bzr selftest --subunit
152
Processing such a stream can be done using a variety of tools including:
154
* The builtin ``subunit2pyunit``, ``subunit-filter``, ``subunit-ls``,
155
``subunit2junitxml`` from the subunit project.
157
* tribunal_, a GUI for showing test results.
159
* testrepository_, a tool for gathering and managing test runs.
161
.. _subunit: https://launchpad.net/subunit/
162
.. _tribunal: https://launchpad.net/tribunal/
168
Bazaar ships with a config file for testrepository_. This can be very
169
useful for keeping track of failing tests and doing general workflow
170
support. To run tests using testrepository::
174
To run only failing tests::
176
$ testr run --failing
178
To run only some tests, without plugins::
180
$ test run test_selftest -- --no-plugins
182
See the testrepository documentation for more details.
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.
234
Normally you should add or update a test for all bug fixes or new features
104
238
Where should I put a new test?
105
239
------------------------------
195
329
We make selective use of doctests__. In general they should provide
196
330
*examples* within the API documentation which can incidentally be tested. We
197
331
don't try to test every important case using doctests |--| regular Python
198
tests are generally a better solution. That is, we just use doctests to
199
make our documentation testable, rather than as a way to make tests.
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.
201
338
Most of these are in ``bzrlib/doc/api``. More additions are welcome.
203
340
__ http://docs.python.org/lib/module-doctest.html
342
There is an `assertDoctestExampleMatches` method in
343
`bzrlib.tests.TestCase` that allows you to match against doctest-style
344
string templates (including ``...`` to skip sections) from regular Python
209
``bzrlib/tests/script.py`` allows users to write tests in a syntax very close to a shell session,
210
using a restricted and limited set of commands that should be enough to mimic
211
most of the behaviours.
351
``bzrlib/tests/script.py`` allows users to write tests in a syntax very
352
close to a shell session, using a restricted and limited set of commands
353
that should be enough to mimic most of the behaviours.
213
355
A script is a set of commands, each command is composed of:
445
You can run files containing shell-like scripts with::
447
$ bzr test-script <script>
449
where ``<script>`` is the path to the file containing the shell-like script.
296
451
The actual use of ScriptRunner within a TestCase looks something like
299
def test_unshelve_keep(self):
302
sr.run_script(self, '''
304
$ bzr shelve --all -m Foo
307
$ bzr unshelve --keep
454
from bzrlib.tests import script
456
def test_unshelve_keep(self):
458
script.run_script(self, '''
460
$ bzr shelve -q --all -m Foo
463
$ bzr unshelve -q --keep
470
You can also test commands that read user interaction::
472
def test_confirm_action(self):
473
"""You can write tests that demonstrate user confirmation"""
474
commands.builtin_command_registry.register(cmd_test_confirm)
475
self.addCleanup(commands.builtin_command_registry.remove, 'test-confirm')
478
2>Really do it? [y/n]:
483
To avoid having to specify "-q" for all commands whose output is
484
irrelevant, the run_script() method may be passed the keyword argument
485
``null_output_matches_anything=True``. For example::
487
def test_ignoring_null_output(self):
490
$ bzr ci -m 'first revision' --unchanged
493
""", null_output_matches_anything=True)
499
`bzrlib.tests.test_import_tariff` has some tests that measure how many
500
Python modules are loaded to run some representative commands.
502
We want to avoid loading code unnecessarily, for reasons including:
504
* Python modules are interpreted when they're loaded, either to define
505
classes or modules or perhaps to initialize some structures.
507
* With a cold cache we may incur blocking real disk IO for each module.
509
* Some modules depend on many others.
511
* Some optional modules such as `testtools` are meant to be soft
512
dependencies and only needed for particular cases. If they're loaded in
513
other cases then bzr may break for people who don't have those modules.
515
`test_import_tariff` allows us to check that removal of imports doesn't
518
This is done by running the command in a subprocess with
519
``--profile-imports``. Starting a whole Python interpreter is pretty
520
slow, so we don't want exhaustive testing here, but just enough to guard
521
against distinct fixed problems.
523
Assertions about precisely what is loaded tend to be brittle so we instead
524
make assertions that particular things aren't loaded.
526
Unless selftest is run with ``--no-plugins``, modules will be loaded in
527
the usual way and checks made on what they cause to be loaded. This is
528
probably worth checking into, because many bzr users have at least some
529
plugins installed (and they're included in binary installers).
531
In theory, plugins might have a good reason to load almost anything:
532
someone might write a plugin that opens a network connection or pops up a
533
gui window every time you run 'bzr status'. However, it's more likely
534
that the code to do these things is just being loaded accidentally. We
535
might eventually need to have a way to make exceptions for particular
538
Some things to check:
540
* non-GUI commands shouldn't load GUI libraries
542
* operations on bzr native formats sholudn't load foreign branch libraries
544
* network code shouldn't be loaded for purely local operations
546
* particularly expensive Python built-in modules shouldn't be loaded
547
unless there is a good reason
320
550
Testing locking behaviour
414
644
KnownFailure should be used with care as we don't want a
415
645
proliferation of quietly broken tests.
417
ModuleAvailableFeature
418
A helper for handling running tests based on whether a python
419
module is available. This can handle 3rd-party dependencies (is
420
``paramiko`` available?) as well as stdlib (``termios``) or
421
extension modules (``bzrlib._groupcompress_pyx``). You create a
422
new feature instance with::
424
MyModuleFeature = ModuleAvailableFeature('bzrlib.something')
427
def test_something(self):
428
self.requireFeature(MyModuleFeature)
429
something = MyModuleFeature.module
432
649
We plan to support three modes for running the test suite to control the
475
692
self.requireFeature(StraceFeature)
480
Features already defined in bzrlib.tests or bzrlib.tests.features include:
485
- UnicodeFilenameFeature,
694
The old naming style for features is CamelCase, but because they're
695
actually instances not classses they're now given instance-style names
698
Features already defined in ``bzrlib.tests`` and ``bzrlib.tests.features``
706
- UnicodeFilenameFeature
486
707
- FTPServerFeature
487
- CaseInsensitiveFilesystemFeature
488
- posix_permissions_feature: the test can rely on unix-style
489
permissions bits on files;
490
generally true on Unix but not on all filesystems
708
- CaseInsensitiveFilesystemFeature.
709
- chown_feature: The test can rely on OS being POSIX and python
711
- posix_permissions_feature: The test can use POSIX-style
712
user/group/other permission bits.
493
715
Defining a new feature that tests can require
508
730
SymlinkFeature = _SymlinkFeature()
732
A helper for handling running tests based on whether a python
733
module is available. This can handle 3rd-party dependencies (is
734
``paramiko`` available?) as well as stdlib (``termios``) or
735
extension modules (``bzrlib._groupcompress_pyx``). You create a
736
new feature instance with::
738
# in bzrlib/tests/features.py
739
apport = tests.ModuleAvailableFeature('apport')
742
# then in bzrlib/tests/test_apport.py
743
class TestApportReporting(TestCaseInTempDir):
745
_test_needs_features = [features.apport]
748
Testing deprecated code
749
-----------------------
751
When code is deprecated, it is still supported for some length of time,
752
usually until the next major version. The ``applyDeprecated`` helper
753
wraps calls to deprecated code to verify that it is correctly issuing the
754
deprecation warning, and also prevents the warnings from being printed
757
Typically patches that apply the ``@deprecated_function`` decorator should
758
update the accompanying tests to use the ``applyDeprecated`` wrapper.
760
``applyDeprecated`` is defined in ``bzrlib.tests.TestCase``. See the API
761
docs for more details.
511
764
Testing exceptions and errors
512
765
-----------------------------
586
839
whether a test should be added for that particular implementation,
587
840
or for all implementations of the interface.
589
The multiplication of tests for different implementations is normally
590
accomplished by overriding the ``load_tests`` function used to load tests
591
from a module. This function typically loads all the tests, then applies
592
a TestProviderAdapter to them, which generates a longer suite containing
593
all the test variations.
595
842
See also `Per-implementation tests`_ (above).
845
Test scenarios and variations
846
-----------------------------
601
848
Some utilities are provided for generating variations of tests. This can
602
849
be used for per-implementation tests, or other cases where the same test
607
854
values to which the test should be applied. The test suite should then
608
855
also provide a list of scenarios in which to run the tests.
610
Typically ``multiply_tests_from_modules`` should be called from the test
611
module's ``load_tests`` function.
857
A single *scenario* is defined by a `(name, parameter_dict)` tuple. The
858
short string name is combined with the name of the test method to form the
859
test instance name. The parameter dict is merged into the instance's
864
load_tests = load_tests_apply_scenarios
866
class TestCheckout(TestCase):
868
scenarios = multiply_scenarios(
869
VaryByRepositoryFormat(),
873
The `load_tests` declaration or definition should be near the top of the
874
file so its effect can be seen.
629
892
A base TestCase that extends the Python standard library's
630
TestCase in several ways. It adds more assertion methods (e.g.
631
``assertContainsRe``), ``addCleanup``, and other features (see its API
632
docs for details). It also has a ``setUp`` that makes sure that
633
global state like registered hooks and loggers won't interfere with
634
your test. All tests should use this base class (whether directly or
893
TestCase in several ways. TestCase is build on
894
``testtools.TestCase``, which gives it support for more assertion
895
methods (e.g. ``assertContainsRe``), ``addCleanup``, and other
896
features (see its API docs for details). It also has a ``setUp`` that
897
makes sure that global state like registered hooks and loggers won't
898
interfere with your test. All tests should use this base class
899
(whether directly or via a subclass). Note that we are trying not to
900
add more assertions at this point, and instead to build up a library
901
of ``bzrlib.tests.matchers``.
637
903
TestCaseWithMemoryTransport
638
904
Extends TestCase and adds methods like ``get_transport``,
711
977
Please see bzrlib.treebuilder for more details.
980
Temporarily changing state
981
~~~~~~~~~~~~~~~~~~~~~~~~~~
983
If your test needs to temporarily mutate some global state, and you need
984
it restored at the end, you can say for example::
986
self.overrideAttr(osutils, '_cached_user_encoding', 'latin-1')
988
Temporarily changing environment variables
989
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
991
If yout test needs to temporarily change some environment variable value
992
(which generally means you want it restored at the end), you can use::
994
self.overrideEnv('BZR_ENV_VAR', 'new_value')
996
If you want to remove a variable from the environment, you should use the
997
special ``None`` value::
999
self.overrideEnv('PATH', None)
1001
If you add a new feature which depends on a new environment variable, make
1002
sure it behaves properly when this variable is not defined (if applicable) and
1003
if you need to enforce a specific default value, check the
1004
``TestCase._cleanEnvironment`` in ``bzrlib.tests.__init__.py`` which defines a
1005
proper set of values for all tests.
1010
Our base ``TestCase`` class provides an ``addCleanup`` method, which
1011
should be used instead of ``tearDown``. All the cleanups are run when the
1012
test finishes, regardless of whether it passes or fails. If one cleanup
1013
fails, later cleanups are still run.
1015
(The same facility is available outside of tests through
1016
``bzrlib.cleanup``.)
1022
Generally we prefer automated testing but sometimes a manual test is the
1023
right thing, especially for performance tests that want to measure elapsed
1024
time rather than effort.
1026
Simulating slow networks
1027
------------------------
1029
To get realistically slow network performance for manually measuring
1030
performance, we can simulate 500ms latency (thus 1000ms round trips)::
1032
$ sudo tc qdisc add dev lo root netem delay 500ms
1034
Normal system behaviour is restored with ::
1036
$ sudo tc qdisc del dev lo root
1038
A more precise version that only filters traffic to port 4155 is::
1040
tc qdisc add dev lo root handle 1: prio
1041
tc qdisc add dev lo parent 1:3 handle 30: netem delay 500ms
1042
tc qdisc add dev lo parent 30:1 handle 40: prio
1043
tc filter add dev lo protocol ip parent 1:0 prio 3 u32 match ip dport 4155 0xffff flowid 1:3 handle 800::800
1044
tc filter add dev lo protocol ip parent 1:0 prio 3 u32 match ip sport 4155 0xffff flowid 1:3 handle 800::801
1046
and to remove this::
1048
tc filter del dev lo protocol ip parent 1: pref 3 u32
1049
tc qdisc del dev lo root handle 1:
1051
You can use similar code to add additional delay to a real network
1052
interface, perhaps only when talking to a particular server or pointing at
1053
a VM. For more information see <http://lartc.org/>.
714
1056
.. |--| unicode:: U+2014
1059
vim: ft=rst tw=74 ai et sw=4
added
removed
doc/developers/testing.txt
