30
34
down the track do not break new features or bug fixes that you are
31
35
contributing today.
33
As of September 2009, Bazaar ships with a test suite containing over
34
23,000 tests and growing. We are proud of it and want to remain so. As
35
community members, we all benefit from it. Would you trust version control
36
on your project to a product *without* a test suite like Bazaar has?
37
As of May 2008, Bazaar ships with a test suite containing over 12000 tests
38
and growing. We are proud of it and want to remain so. As community
39
members, we all benefit from it. Would you trust version control on
40
your project to a product *without* a test suite like Bazaar has?
39
43
Running the Test Suite
40
44
======================
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
------------------------
60
46
Currently, bzr selftest is used to invoke tests.
61
47
You can provide a pattern argument to run a subset. For example,
62
48
to run just the blackbox tests, run::
136
101
This can provide useful logging to help debug test failures when used
137
102
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
238
108
Where should I put a new test?
239
109
------------------------------
308
178
Per-implementation tests are tests that are defined once and then run
309
179
against multiple implementations of an interface. For example,
310
``per_transport.py`` defines tests that all Transport implementations
311
(local filesystem, HTTP, and so on) must pass. They are found in
312
``bzrlib/tests/per_*/*.py``, and ``bzrlib/tests/per_*.py``.
180
``test_transport_implementations.py`` defines tests that all Transport
181
implementations (local filesystem, HTTP, and so on) must pass.
183
They are found in ``bzrlib/tests/*_implementations/test_*.py``,
184
``bzrlib/tests/per_*/*.py``, and
185
``bzrlib/tests/test_*_implementations.py``.
314
187
These are really a sub-category of unit tests, but an important one.
316
Along the same lines are tests for extension modules. We generally have
317
both a pure-python and a compiled implementation for each module. As such,
318
we want to run the same tests against both implementations. These can
319
generally be found in ``bzrlib/tests/*__*.py`` since extension modules are
320
usually prefixed with an underscore. Since there are only two
321
implementations, we have a helper function
322
``bzrlib.tests.permute_for_extension``, which can simplify the
323
``load_tests`` implementation.
337
201
__ http://docs.python.org/lib/module-doctest.html
343
``bzrlib/tests/script.py`` allows users to write tests in a syntax very close to a shell session,
344
using a restricted and limited set of commands that should be enough to mimic
345
most of the behaviours.
347
A script is a set of commands, each command is composed of:
349
* one mandatory command line,
350
* one optional set of input lines to feed the command,
351
* one optional set of output expected lines,
352
* one optional set of error expected lines.
354
Input, output and error lines can be specified in any order.
356
Except for the expected output, all lines start with a special
357
string (based on their origin when used under a Unix shell):
359
* '$ ' for the command,
361
* nothing for output,
364
Comments can be added anywhere, they start with '#' and end with
367
The execution stops as soon as an expected output or an expected error is not
370
When no output is specified, any ouput from the command is accepted
371
and execution continue.
373
If an error occurs and no expected error is specified, the execution stops.
375
An error is defined by a returned status different from zero, not by the
376
presence of text on the error stream.
378
The matching is done on a full string comparison basis unless '...' is used, in
379
which case expected output/errors can be less precise.
383
The following will succeeds only if 'bzr add' outputs 'adding file'::
388
If you want the command to succeed for any output, just use::
392
The following will stop with an error::
396
If you want it to succeed, use::
399
2> bzr: ERROR: unknown command "not-a-command"
401
You can use ellipsis (...) to replace any piece of text you don't want to be
404
$ bzr branch not-a-branch
405
2>bzr: ERROR: Not a branch...not-a-branch/".
407
This can be used to ignore entire lines too::
413
# And here we explain that surprising fourth line
420
You can check the content of a file with cat::
425
You can also check the existence of a file with cat, the following will fail if
426
the file doesn't exist::
430
The actual use of ScriptRunner within a TestCase looks something like
433
from bzrlib.tests import script
435
def test_unshelve_keep(self):
437
script.run_script(self, '''
439
$ bzr shelve --all -m Foo
442
$ bzr unshelve --keep
449
You can also test commands that read user interaction::
451
def test_confirm_action(self):
452
"""You can write tests that demonstrate user confirmation"""
453
commands.builtin_command_registry.register(cmd_test_confirm)
454
self.addCleanup(commands.builtin_command_registry.remove, 'test-confirm')
457
2>Really do it? [y/n]:
465
`bzrlib.tests.test_import_tariff` has some tests that measure how many
466
Python modules are loaded to run some representative commands.
468
We want to avoid loading code unnecessarily, for reasons including:
470
* Python modules are interpreted when they're loaded, either to define
471
classes or modules or perhaps to initialize some structures.
473
* With a cold cache we may incur blocking real disk IO for each module.
475
* Some modules depend on many others.
477
* Some optional modules such as `testtools` are meant to be soft
478
dependencies and only needed for particular cases. If they're loaded in
479
other cases then bzr may break for people who don't have those modules.
481
`test_import_tariff` allows us to check that removal of imports doesn't
484
This is done by running the command in a subprocess with
485
``--profile-imports``. Starting a whole Python interpreter is pretty
486
slow, so we don't want exhaustive testing here, but just enough to guard
487
against distinct fixed problems.
489
Assertions about precisely what is loaded tend to be brittle so we instead
490
make assertions that particular things aren't loaded.
492
Unless selftest is run with ``--no-plugins``, modules will be loaded in
493
the usual way and checks made on what they cause to be loaded. This is
494
probably worth checking into, because many bzr users have at least some
495
plugins installed (and they're included in binary installers).
497
In theory, plugins might have a good reason to load almost anything:
498
someone might write a plugin that opens a network connection or pops up a
499
gui window every time you run 'bzr status'. However, it's more likely
500
that the code to do these things is just being loaded accidentally. We
501
might eventually need to have a way to make exceptions for particular
504
Some things to check:
506
* non-GUI commands shouldn't load GUI libraries
508
* operations on bzr native formats sholudn't load foreign branch libraries
510
* network code shouldn't be loaded for purely local operations
512
* particularly expensive Python built-in modules shouldn't be loaded
513
unless there is a good reason
516
Testing locking behaviour
517
-------------------------
519
In order to test the locking behaviour of commands, it is possible to install
520
a hook that is called when a write lock is: acquired, released or broken.
521
(Read locks also exist, they cannot be discovered in this way.)
523
A hook can be installed by calling bzrlib.lock.Lock.hooks.install_named_hook.
524
The three valid hooks are: `lock_acquired`, `lock_released` and `lock_broken`.
531
lock.Lock.hooks.install_named_hook('lock_acquired',
532
locks_acquired.append, None)
533
lock.Lock.hooks.install_named_hook('lock_released',
534
locks_released.append, None)
536
`locks_acquired` will now receive a LockResult instance for all locks acquired
537
since the time the hook is installed.
539
The last part of the `lock_url` allows you to identify the type of object that is locked.
541
- BzrDir: `/branch-lock`
542
- Working tree: `/checkout/lock`
543
- Branch: `/branch/lock`
544
- Repository: `/repository/lock`
546
To test if a lock is a write lock on a working tree, one can do the following::
548
self.assertEndsWith(locks_acquired[0].lock_url, "/checkout/lock")
550
See bzrlib/tests/commands/test_revert.py for an example of how to use this for
686
328
``_probe`` and ``feature_name`` methods. For example::
688
330
class _SymlinkFeature(Feature):
690
332
def _probe(self):
691
333
return osutils.has_symlinks()
693
335
def feature_name(self):
694
336
return 'symlinks'
696
338
SymlinkFeature = _SymlinkFeature()
698
A helper for handling running tests based on whether a python
699
module is available. This can handle 3rd-party dependencies (is
700
``paramiko`` available?) as well as stdlib (``termios``) or
701
extension modules (``bzrlib._groupcompress_pyx``). You create a
702
new feature instance with::
704
# in bzrlib/tests/features.py
705
apport = tests.ModuleAvailableFeature('apport')
708
# then in bzrlib/tests/test_apport.py
709
class TestApportReporting(TestCaseInTempDir):
711
_test_needs_features = [features.apport]
714
Testing deprecated code
715
-----------------------
717
When code is deprecated, it is still supported for some length of time,
718
usually until the next major version. The ``applyDeprecated`` helper
719
wraps calls to deprecated code to verify that it is correctly issuing the
720
deprecation warning, and also prevents the warnings from being printed
723
Typically patches that apply the ``@deprecated_function`` decorator should
724
update the accompanying tests to use the ``applyDeprecated`` wrapper.
726
``applyDeprecated`` is defined in ``bzrlib.tests.TestCase``. See the API
727
docs for more details.
730
341
Testing exceptions and errors
731
342
-----------------------------
848
459
A base TestCase that extends the Python standard library's
849
TestCase in several ways. TestCase is build on
850
``testtools.TestCase``, which gives it support for more assertion
851
methods (e.g. ``assertContainsRe``), ``addCleanup``, and other
852
features (see its API docs for details). It also has a ``setUp`` that
853
makes sure that global state like registered hooks and loggers won't
854
interfere with your test. All tests should use this base class
855
(whether directly or via a subclass). Note that we are trying not to
856
add more assertions at this point, and instead to build up a library
857
of ``bzrlib.tests.matchers``.
460
TestCase in several ways. It adds more assertion methods (e.g.
461
``assertContainsRe``), ``addCleanup``, and other features (see its API
462
docs for details). It also has a ``setUp`` that makes sure that
463
global state like registered hooks and loggers won't interfere with
464
your test. All tests should use this base class (whether directly or
859
467
TestCaseWithMemoryTransport
860
468
Extends TestCase and adds methods like ``get_transport``,
933
541
Please see bzrlib.treebuilder for more details.
936
Temporarily changing state
937
~~~~~~~~~~~~~~~~~~~~~~~~~~
939
If your test needs to temporarily mutate some global state, and you need
940
it restored at the end, you can say for example::
942
self.overrideAttr(osutils, '_cached_user_encoding', 'latin-1')
947
Our base ``TestCase`` class provides an ``addCleanup`` method, which
948
should be used instead of ``tearDown``. All the cleanups are run when the
949
test finishes, regardless of whether it passes or fails. If one cleanup
950
fails, later cleanups are still run.
952
(The same facility is available outside of tests through
959
Generally we prefer automated testing but sometimes a manual test is the
960
right thing, especially for performance tests that want to measure elapsed
961
time rather than effort.
963
Simulating slow networks
964
------------------------
966
To get realistically slow network performance for manually measuring
967
performance, we can simulate 500ms latency (thus 1000ms round trips)::
969
$ sudo tc qdisc add dev lo root netem delay 500ms
971
Normal system behaviour is restored with ::
973
$ sudo tc qdisc del dev lo root
975
A more precise version that only filters traffic to port 4155 is::
977
tc qdisc add dev lo root handle 1: prio
978
tc qdisc add dev lo parent 1:3 handle 30: netem delay 500ms
979
tc qdisc add dev lo parent 30:1 handle 40: prio
980
tc filter add dev lo protocol ip parent 1:0 prio 3 u32 match ip dport 4155 0xffff flowid 1:3 handle 800::800
981
tc filter add dev lo protocol ip parent 1:0 prio 3 u32 match ip sport 4155 0xffff flowid 1:3 handle 800::801
985
tc filter del dev lo protocol ip parent 1: pref 3 u32
986
tc qdisc del dev lo root handle 1:
988
You can use similar code to add additional delay to a real network
989
interface, perhaps only when talking to a particular server or pointing at
990
a VM. For more information see <http://lartc.org/>.
993
544
.. |--| unicode:: U+2014
996
vim: ft=rst tw=74 ai et sw=4
added
removed
doc/developers/testing.txt
