34
30
down the track do not break new features or bug fixes that you are
35
31
contributing today.
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?
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?
43
39
Running the Test Suite
44
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
------------------------
46
60
Currently, bzr selftest is used to invoke tests.
47
61
You can provide a pattern argument to run a subset. For example,
48
62
to run just the blackbox tests, run::
101
136
This can provide useful logging to help debug test failures when used
102
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
108
238
Where should I put a new test?
109
239
------------------------------
178
308
Per-implementation tests are tests that are defined once and then run
179
309
against multiple implementations of an interface. For example,
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``.
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``.
187
314
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.
201
337
__ 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
453
`bzrlib.tests.test_import_tariff` has some tests that measure how many
454
Python modules are loaded to run some representative commands.
456
We want to avoid loading code unnecessarily, for reasons including:
458
* Python modules are interpreted when they're loaded, either to define
459
classes or modules or perhaps to initialize some structures.
461
* With a cold cache we may incur blocking real disk IO for each module.
463
* Some modules depend on many others.
465
* Some optional modules such as `testtools` are meant to be soft
466
dependencies and only needed for particular cases. If they're loaded in
467
other cases then bzr may break for people who don't have those modules.
469
`test_import_tariff` allows us to check that removal of imports doesn't
472
This is done by running the command in a subprocess with
473
``--profile-imports``. Starting a whole Python interpreter is pretty
474
slow, so we don't want exhaustive testing here, but just enough to guard
475
against distinct fixed problems.
477
Assertions about precisely what is loaded tend to be brittle so we instead
478
make assertions that particular things aren't loaded.
480
Unless selftest is run with ``--no-plugins``, modules will be loaded in
481
the usual way and checks made on what they cause to be loaded. This is
482
probably worth checking into, because many bzr users have at least some
483
plugins installed (and they're included in binary installers).
485
In theory, plugins might have a good reason to load almost anything:
486
someone might write a plugin that opens a network connection or pops up a
487
gui window every time you run 'bzr status'. However, it's more likely
488
that the code to do these things is just being loaded accidentally. We
489
might eventually need to have a way to make exceptions for particular
492
Some things to check:
494
* non-GUI commands shouldn't load GUI libraries
496
* operations on bzr native formats sholudn't load foreign branch libraries
498
* network code shouldn't be loaded for purely local operations
500
* particularly expensive Python built-in modules shouldn't be loaded
501
unless there is a good reason
504
Testing locking behaviour
505
-------------------------
507
In order to test the locking behaviour of commands, it is possible to install
508
a hook that is called when a write lock is: acquired, released or broken.
509
(Read locks also exist, they cannot be discovered in this way.)
511
A hook can be installed by calling bzrlib.lock.Lock.hooks.install_named_hook.
512
The three valid hooks are: `lock_acquired`, `lock_released` and `lock_broken`.
519
lock.Lock.hooks.install_named_hook('lock_acquired',
520
locks_acquired.append, None)
521
lock.Lock.hooks.install_named_hook('lock_released',
522
locks_released.append, None)
524
`locks_acquired` will now receive a LockResult instance for all locks acquired
525
since the time the hook is installed.
527
The last part of the `lock_url` allows you to identify the type of object that is locked.
529
- BzrDir: `/branch-lock`
530
- Working tree: `/checkout/lock`
531
- Branch: `/branch/lock`
532
- Repository: `/repository/lock`
534
To test if a lock is a write lock on a working tree, one can do the following::
536
self.assertEndsWith(locks_acquired[0].lock_url, "/checkout/lock")
538
See bzrlib/tests/commands/test_revert.py for an example of how to use this for
459
820
A base TestCase that extends the Python standard library's
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
821
TestCase in several ways. TestCase is build on
822
``testtools.TestCase``, which gives it support for more assertion
823
methods (e.g. ``assertContainsRe``), ``addCleanup``, and other
824
features (see its API docs for details). It also has a ``setUp`` that
825
makes sure that global state like registered hooks and loggers won't
826
interfere with your test. All tests should use this base class
827
(whether directly or via a subclass). Note that we are trying not to
828
add more assertions at this point, and instead to build up a library
829
of ``bzrlib.tests.matchers``.
467
831
TestCaseWithMemoryTransport
468
832
Extends TestCase and adds methods like ``get_transport``,
541
905
Please see bzrlib.treebuilder for more details.
908
Temporarily changing state
909
~~~~~~~~~~~~~~~~~~~~~~~~~~
911
If your test needs to temporarily mutate some global state, and you need
912
it restored at the end, you can say for example::
914
self.overrideAttr(osutils, '_cached_user_encoding', 'latin-1')
919
Our base ``TestCase`` class provides an ``addCleanup`` method, which
920
should be used instead of ``tearDown``. All the cleanups are run when the
921
test finishes, regardless of whether it passes or fails. If one cleanup
922
fails, later cleanups are still run.
924
(The same facility is available outside of tests through
931
Generally we prefer automated testing but sometimes a manual test is the
932
right thing, especially for performance tests that want to measure elapsed
933
time rather than effort.
935
Simulating slow networks
936
------------------------
938
To get realistically slow network performance for manually measuring
939
performance, we can simulate 500ms latency (thus 1000ms round trips)::
941
$ sudo tc qdisc add dev lo root netem delay 500ms
943
Normal system behaviour is restored with ::
945
$ sudo tc qdisc del dev lo root
947
A more precise version that only filters traffic to port 4155 is::
949
tc qdisc add dev lo root handle 1: prio
950
tc qdisc add dev lo parent 1:3 handle 30: netem delay 500ms
951
tc qdisc add dev lo parent 30:1 handle 40: prio
952
tc filter add dev lo protocol ip parent 1:0 prio 3 u32 match ip dport 4155 0xffff flowid 1:3 handle 800::800
953
tc filter add dev lo protocol ip parent 1:0 prio 3 u32 match ip sport 4155 0xffff flowid 1:3 handle 800::801
957
tc filter del dev lo protocol ip parent 1: pref 3 u32
958
tc qdisc del dev lo root handle 1:
960
You can use similar code to add additional delay to a real network
961
interface, perhaps only when talking to a particular server or pointing at
962
a VM. For more information see <http://lartc.org/>.
544
965
.. |--| unicode:: U+2014
968
vim: ft=rst tw=74 ai et sw=4
added
removed
doc/developers/testing.txt
