Testing

Installing the testing tool

Every Grok-based project will install a test runner that can find and run all test cases for your project. This test runner is installed using Buildout with the zc.recipe.testrunner recipe. The default configuration is:

[test]
recipe = zc.recipe.testrunner
eggs = <my-grok-project-name>
defaults = ['--tests-pattern', '^f?tests$', '-v']

Using the test runner

The test runner can be invoked by the test program in your projects bin directory.

usage

Usage: test [options] [MODULE] [TEST]

options: help

-h, --help

show this help message and exit

options: searching and filtering

options in this group are used to define which tests to run.

-s PACKAGE, --package=PACKAGE, --dir=PACKAGE
	Search the given package’s directories for tests. This can be specified more than once to run tests in multiple parts of the source tree. For example, if refactoring interfaces, you don’t want to see the way you have broken setups for tests in other packages. You just want to run the interface tests. Packages are supplied as dotted names. For compatibility with the old test runner, forward and backward slashed in package names are converted to dots. (In the special case of packages spread over multiple directories, only directories within the test search path are searched. See the –path option.)
-m MODULE, --module=MODULE
	Specify a test-module filter as a regular expression. This is a case-sensitive regular expression, used in search (not match) mode, to limit which test modules are searched for tests. The regular expressions are checked against dotted module names. In an extension of Python regexp notation, a leading ”!” is stripped and causes the sense of the remaining regexp to be negated (so ”!bc” matches any string that does not match “bc”, and vice versa). The option can be specified multiple test-module filters. Test modules matching any of the test filters are searched. If no test-module filter is specified, then all test modules are used.
-t TEST, --test=TEST
	Specify a test filter as a regular expression. This is a case-sensitive regular expression, used in search (not match) mode, to limit which tests are run. In an extension of Python regexp notation, a leading ”!” is stripped and causes the sense of the remaining regexp to be negated (so ”!bc” matches any string that does not match “bc”, and vice versa). The option can be specified multiple test filters. Tests matching any of the test filters are included. If no test filter is specified, then all tests are run.
-u, --unit	Run only unit tests, ignoring any layer options.
-f, --non-unit	Run tests other than unit tests.
--layer=LAYER	Specify a test layer to run. The option can be given multiple times to specify more than one layer. If not specified, all layers are run. It is common for the running script to provide default values for this option. Layers are specified regular expressions, used in search mode, for dotted names of objects that define a layer. In an extension of Python regexp notation, a leading ”!” is stripped and causes the sense of the remaining regexp to be negated (so ”!bc” matches any string that does not match “bc”, and vice versa). The layer named ‘unit’ is reserved for unit tests, however, take note of the –unit and non-unit options.
-a AT_LEVEL, --at-level=AT_LEVEL
	Run the tests at the given level. Any test at a level at or below this is run, any test at a level above this is not run. Level 0 runs all tests.
--all	Run tests at all levels.
--list-tests	List all tests that matched your filters. Do not run any tests.

options: reporting

Reporting options control basic aspects of test-runner output

-v, --verbose	Make output more verbose. Increment the verbosity level.
-q, --quiet	Make the output minimal, overriding any verbosity options.
-p, --progress	Output progress status
--no-progress	Do not output progress status. This is the default, but can be used to counter a previous use of –progress or -p.
--auto-progress
	Output progress status, but only when stdout is a terminal.
-c, --color	Colorize the output.
-C, --no-color	Do not colorize the output. This is the default, but can be used to counter a previous use of –color or -c.
--auto-color	Colorize the output, but only when stdout is a terminal.
--slow-test=N	With -c and -vvv, highlight tests that take longer than N seconds (default: 10).
-1, --hide-secondary-failures
	Report only the first failure in a doctest. (Examples after the failure are still executed, in case they do any cleanup.)
--show-secondary-failures
	Report all failures in a doctest. This is the default, but can be used to counter a default use of -1 or –hide-secondary-failures.
--ndiff	When there is a doctest failure, show it as a diff using the ndiff.py utility.
--udiff	When there is a doctest failure, show it as a unified diff.
--cdiff	When there is a doctest failure, show it as a context diff.

options: analysis

Analysis options provide tools for analysing test output.

-D, --post-mortem
	Enable post-mortem debugging of test failures
-g GC, --gc=GC	Set the garbage collector generation threshold. This can be used to stress memory and gc correctness. Some crashes are only reproducible when the threshold is set to 1 (aggressive garbage collection). Do “–gc 0” to disable garbage collection altogether. The –gc option can be used up to 3 times to specify up to 3 of the 3 Python gc_threshold settings.
-G GC_OPTION, --gc-option=GC_OPTION
	Set a Python gc-module debug flag. This option can be used more than once to set multiple flags.
-N REPEAT, --repeat=REPEAT
	Repeat the tests the given number of times. This option is used to make sure that tests leave their environment in the state they found it and, with the –report-refcounts option to look for memory leaks.
-r, --report-refcounts
	After each run of the tests, output a report summarizing changes in refcounts by object type. This option that requires that Python was built with the –with-pydebug option to configure.
--coverage=COVERAGE
	Perform code-coverage analysis, saving trace data to the directory with the given name. A code coverage summary is printed to standard out.
--profile=PROFILE
	Run the tests under cProfiler or hotshot and display the top 50 stats, sorted by cumulative time and number of calls.
--pychecker	Run the tests under pychecker

options: setup

Setup options are normally supplied by the testrunner script, although they can be overridden by users.

--path=PATH	Specify a path to be added to Python’s search path. This option can be used multiple times to specify multiple search paths. The path is usually specified by the test-runner script itself, rather than by users of the script, although it can be overridden by users. Only tests found in the path will be run. This option also specifies directories to be searched for tests. See the search_directory.
--test-path=TEST_PATH
	Specify a path to be searched for tests, but not added to the Python search path. This option can be used multiple times to specify multiple search paths. The path is usually specified by the test-runner script itself, rather than by users of the script, although it can be overridden by users. Only tests found in the path will be run.
--package-path=PACKAGE_PATH
	Specify a path to be searched for tests, but not added to the Python search path. Also specify a package for files found in this path. This is used to deal with directories that are stitched into packages that are not otherwise searched for tests. This option takes 2 arguments. The first is a path name. The second is the package name. This option can be used multiple times to specify multiple search paths. The path is usually specified by the test-runner script itself, rather than by users of the script, although it can be overridden by users. Only tests found in the path will be run.
--tests-pattern=TESTS_PATTERN
	The test runner looks for modules containing tests. It uses this pattern to identify these modules. The modules may be either packages or python files. If a test module is a package, it uses the value given by the test-file-pattern to identify python files within the package containing tests.
--suite-name=SUITE_NAME
	Specify the name of the object in each test_module that contains the module’s test suite.
--test-file-pattern=TEST_FILE_PATTERN
	Specify a pattern for identifying python files within a tests package. See the documentation for the –tests-pattern option.
--ignore_dir=IGNORE_DIR
	Specifies the name of a directory to ignore when looking for tests.

options: other

Other options

-k, --keepbytecode
	Normally, the test runner scans the test paths and the test directories looking for and deleting pyc or pyo files without corresponding py files. This is to prevent spurious test failures due to finding compiled modules where source modules have been deleted. This scan can be time consuming. Using this option disables this scan. If you know you haven’t removed any modules since last running the tests, can make the test run go much faster.
--usecompiled	Normally, a package must contain an __init__.py file, and only .py files can contain test code. When this option is specified, compiled Python files (.pyc and .pyo) can be used instead: a directory containing __init__.pyc or __init__.pyo is also considered to be a package, and if file XYZ.py contains tests but is absent while XYZ.pyc or XYZ.pyo exists then the compiled files will be used. This is necessary when running tests against a tree where the .py files have been removed after compilation to .pyc/.pyo. Use of this option implies –keepbytecode.
--exit-with-status
	Return an error exit status if the tests failed. This can be useful for an invoking process that wants to monitor the result of a test run.

Discovering Test Cases

The test runner looks for modules containing tests. It uses the default pattern of ‘^f?tests$’ to identify these modules. The test runner will then use the name test_suite in all matching modules as the object to provide test suites.

Test Supporting API

To support testing in Grok-based projects, Grok comes with a couple of helpers located in the grok.testing module.

Grok test helpers.

grok.testing.grok_component(name, component, context=None, module_info=None, templates=None)

Grok a single component.

This function can be used to grok individual components within a doctest, such as adapters. It sets up just enough context for some grokking to work, though more complicated grokkers which need module context (such as view grokkers) might not work.

Returns True or False depending on whether the grokking worked or not.

A sample doctest could look as follows:

This defines the object we want to provide an adapter for:

>>> class Bar(object):
...    pass

This is the interface that we want to adapt to:

>>> from zope.interface import Interface
>>> class IFoo(Interface):
...    pass

This is the adapter itself:

>>> import grokcore.component as grok
>>> class MyAdapter(grok.Adapter):
...    grok.provides(IFoo)
...    grok.context(Bar)

Now we will register the adapter using grok_component():

>>> from grok.testing import grok, grok_component
>>> grok('grokcore.component.meta')
>>> grok_component('MyAdapter', MyAdapter)
True

The adapter should now be available:

>>> adapted = IFoo(Bar())
>>> isinstance(adapted, MyAdapter)
True

Deprecated since version 1.0: Use grokcore.component.testing.grok_component() instead.

grok.testing.grok(module_name)

Grok a module.

Test helper to ‘grok’ a module named by module_name, a dotted path to a module like 'mypkg.mymodule'. ‘grokking’ hereby means to do all the ZCML configurations triggered by directives like grok.context() etc. This is only needed if your module was not grokked during test setup time as it normally happens with functional tests.

grok.testing.warn(message, category=None, stacklevel=1)

Intended to replace warnings.warn in tests.

Modified copy from zope.deprecation.tests to:

• make the signature identical to warnings.warn
• to check for *.pyc and *.pyo files.

When zope.deprecation is fixed, this warn function can be removed again.