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We make selective use of doctests__. In general they should provide
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*examples* within the API documentation which can incidentally be tested. We
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don't try to test every important case using doctests |--| regular Python
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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
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doctests are not as well isolated as the unit tests, if you need more
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isolation, you're likely want to write unit tests anyway if only to get a
336
better control of the test environment.
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tests are generally a better solution. That is, we just use doctests to
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make our documentation testable, rather than as a way to make tests.
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Most of these are in ``bzrlib/doc/api``. More additions are welcome.
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__ http://docs.python.org/lib/module-doctest.html
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There is an `assertDoctestExampleMatches` method in
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`bzrlib.tests.TestCase` that allows you to match against doctest-style
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string templates (including ``...`` to skip sections) from regular Python
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``bzrlib/tests/script.py`` allows users to write tests in a syntax very
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close to a shell session, using a restricted and limited set of commands
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that should be enough to mimic most of the behaviours.
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``bzrlib/tests/script.py`` allows users to write tests in a syntax very close to a shell session,
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using a restricted and limited set of commands that should be enough to mimic
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most of the behaviours.
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A script is a set of commands, each command is composed of:
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The execution stops as soon as an expected output or an expected error is not
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If output occurs and no output is expected, the execution stops and the
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test fails. If unexpected output occurs on the standard error, then
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execution stops and the test fails.
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When no output is specified, any ouput from the command is accepted
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and execution continue.
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If an error occurs and no expected error is specified, the execution stops.
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You can run files containing shell-like scripts with::
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$ bzr test-script <script>
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where ``<script>`` is the path to the file containing the shell-like script.
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The actual use of ScriptRunner within a TestCase looks something like
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435
def test_unshelve_keep(self):
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436
# some setup here
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script.run_script(self, '''
460
$ bzr shelve -q --all -m Foo
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$ bzr shelve --all -m Foo
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$ bzr shelve --list
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$ bzr unshelve -q --keep
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$ bzr unshelve --keep
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$ bzr shelve --list
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To avoid having to specify "-q" for all commands whose output is
484
irrelevant, the run_script() method may be passed the keyword argument
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``null_output_matches_anything=True``. For example::
487
def test_ignoring_null_output(self):
490
$ bzr ci -m 'first revision' --unchanged
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""", null_output_matches_anything=True)
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Import tariff tests
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-------------------
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This is done by running the command in a subprocess with
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``PYTHON_VERBOSE=1``. Starting a whole Python interpreter is pretty slow,
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so we don't want exhaustive testing here, but just enough to guard against
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distinct fixed problems.
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``--profile-imports``. Starting a whole Python interpreter is pretty
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slow, so we don't want exhaustive testing here, but just enough to guard
487
against distinct fixed problems.
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Assertions about precisely what is loaded tend to be brittle so we instead
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make assertions that particular things aren't loaded.
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whether a test should be added for that particular implementation,
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or for all implementations of the interface.
808
The multiplication of tests for different implementations is normally
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accomplished by overriding the ``load_tests`` function used to load tests
810
from a module. This function typically loads all the tests, then applies
811
a TestProviderAdapter to them, which generates a longer suite containing
812
all the test variations.
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See also `Per-implementation tests`_ (above).
845
Test scenarios and variations
846
-----------------------------
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Some utilities are provided for generating variations of tests. This can
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be used for per-implementation tests, or other cases where the same test
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826
values to which the test should be applied. The test suite should then
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827
also provide a list of scenarios in which to run the tests.
857
A single *scenario* is defined by a `(name, parameter_dict)` tuple. The
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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
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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.
829
Typically ``multiply_tests_from_modules`` should be called from the test
830
module's ``load_tests`` function.
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Please see bzrlib.treebuilder for more details.
982
PreviewTrees are based on TreeTransforms. This means they can represent
983
virtually any state that a WorkingTree can have, including unversioned files.
984
They can be used to test the output of anything that produces TreeTransforms,
985
such as merge algorithms and revert. They can also be used to test anything
986
that takes arbitrary Trees as its input.
990
# Get an empty tree to base the transform on.
991
b = self.make_branch('.')
992
empty_tree = b.repository.revision_tree(_mod_revision.NULL_REVISION)
993
tt = TransformPreview(empty_tree)
994
self.addCleanup(tt.finalize)
995
# Empty trees don't have a root, so add it first.
996
root = tt.new_directory('', ROOT_PARENT, 'tree-root')
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# Set the contents of a file.
998
tt.new_file('new-file', root, 'contents', 'file-id')
999
preview = tt.get_preview_tree()
1000
# Test the contents.
1001
self.assertEqual('contents', preview.get_file_text('file-id'))
1003
PreviewTrees can stack, with each tree falling back to the previous::
1005
tt2 = TransformPreview(preview)
1006
self.addCleanup(tt2.finalize)
1007
tt2.new_file('new-file2', tt2.root, 'contents2', 'file-id2')
1008
preview2 = tt2.get_preview_tree()
1009
self.assertEqual('contents', preview2.get_file_text('file-id'))
1010
self.assertEqual('contents2', preview2.get_file_text('file-id2'))
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936
Temporarily changing state
1014
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~~~~~~~~~~~~~~~~~~~~~~~~~~
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self.overrideAttr(osutils, '_cached_user_encoding', 'latin-1')
1021
Temporarily changing environment variables
1022
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1024
If yout test needs to temporarily change some environment variable value
1025
(which generally means you want it restored at the end), you can use::
1027
self.overrideEnv('BZR_ENV_VAR', 'new_value')
1029
If you want to remove a variable from the environment, you should use the
1030
special ``None`` value::
1032
self.overrideEnv('PATH', None)
1034
If you add a new feature which depends on a new environment variable, make
1035
sure it behaves properly when this variable is not defined (if applicable) and
1036
if you need to enforce a specific default value, check the
1037
``TestCase._cleanEnvironment`` in ``bzrlib.tests.__init__.py`` which defines a
1038
proper set of values for all tests.
added
removed
doc/developers/testing.txt
