File: //usr/lib/python2.6/site-packages/nose/plugins/base.py
import os
import textwrap
from optparse import OptionConflictError
from warnings import warn
from nose.util import tolist
class Plugin(object):
"""Base class for nose plugins. It's not *necessary* to subclass this
class to create a plugin; however, all plugins must implement
`options(self, parser, env)` and `configure(self, options, conf)`, and
must have the attributes `enabled`, `name` and `score`. The `name`
attribute may contain hyphens ('-').
Plugins should not be enabled by default.
Subclassing Plugin (and calling the superclass methods in
__init__, configure, and options, if you override them) will give
your plugin some friendly default behavior:
* A --with-$name option will be added to the command line interface
to enable the plugin, and a corresponding environment variable
will be used as the default value. The plugin class's docstring
will be used as the help for this option.
* The plugin will not be enabled unless this option is selected by
the user.
"""
can_configure = False
enabled = False
enableOpt = None
name = None
score = 100
def __init__(self):
if self.name is None:
self.name = self.__class__.__name__.lower()
if self.enableOpt is None:
self.enableOpt = "enable_plugin_%s" % self.name.replace('-', '_')
def addOptions(self, parser, env=os.environ):
"""Add command-line options for this plugin.
The base plugin class adds --with-$name by default, used to enable the
plugin.
"""
self.add_options(parser, env)
def add_options(self, parser, env=os.environ):
"""Non-camel-case version of func name for backwards compatibility.
"""
# FIXME raise deprecation warning if wasn't called by wrapper
try:
self.options(parser, env)
self.can_configure = True
except OptionConflictError, e:
warn("Plugin %s has conflicting option string: %s and will "
"be disabled" % (self, e), RuntimeWarning)
self.enabled = False
self.can_configure = False
def options(self, parser, env=os.environ):
"""New plugin API: override to just set options. Implement
this method instead of addOptions or add_options for normal
options behavior with protection from OptionConflictErrors.
"""
env_opt = 'NOSE_WITH_%s' % self.name.upper()
env_opt = env_opt.replace('-', '_')
parser.add_option("--with-%s" % self.name,
action="store_true",
dest=self.enableOpt,
default=env.get(env_opt),
help="Enable plugin %s: %s [%s]" %
(self.__class__.__name__, self.help(), env_opt))
def configure(self, options, conf):
"""Configure the plugin and system, based on selected options.
The base plugin class sets the plugin to enabled if the enable option
for the plugin (self.enableOpt) is true.
"""
if not self.can_configure:
return
self.conf = conf
if hasattr(options, self.enableOpt):
self.enabled = getattr(options, self.enableOpt)
def help(self):
"""Return help for this plugin. This will be output as the help
section of the --with-$name option that enables the plugin.
"""
if self.__class__.__doc__:
# doc sections are often indented; compress the spaces
return textwrap.dedent(self.__class__.__doc__)
return "(no help available)"
# Compatiblity shim
def tolist(self, val):
warn("Plugin.tolist is deprecated. Use nose.util.tolist instead",
DeprecationWarning)
return tolist(val)
class IPluginInterface(object):
"""
Nose plugin API
---------------
While it is recommended that plugins subclass
nose.plugins.Plugin, the only requirements for a plugin are
that it implement the methods `options(self, parser, env)` and
`configure(self, options, conf)`, and have the attributes
`enabled`, `name` and `score`.
Plugins may implement any or all of the methods documented
below. Please note that they *must not* subclass `IPluginInterface`;
`IPluginInterface` is a only description of the plugin API.
When plugins are called, the first plugin that implements a method
and returns a non-None value wins, and plugin processing ends. The
exceptions to this are methods marked as `generative` or
`chainable`. `generative` methods combine the output of all
plugins that respond with an iterable into a single flattened
iterable response (a generator, really). `chainable` methods pass
the results of calling plugin A as the input to plugin B, where
the positions in the chain are determined by the plugin sort
order, which is in order by `score` descending.
In general, plugin methods correspond directly to methods of
`nose.selector.Selector`, `nose.loader.TestLoader` and
`nose.result.TextTestResult` are called by those methods when they are
called. In some cases, the plugin hook doesn't neatly match the
method in which it is called; for those, the documentation for the
hook will tell you where in the test process it is called.
Plugin hooks fall into four broad categories: selecting and
loading tests, handling errors raised by tests, preparing objects
used in the testing process, and watching and reporting on test
results.
Selecting and loading tests
===========================
To alter test selection behavior, implement any necessary `want*`
methods as outlined below. Keep in mind, though, that when your
plugin returns True from a `want*` method, you will send the requested
object through the normal test collection process. If the object
represents something from which normal tests can't be collected, you
must also implement a loader method to load the tests.
Examples:
* The builtin doctests plugin implements `wantFile` to enable
loading of doctests from files that are not python modules. It
also implements `loadTestsFromModule` to load doctests from
python modules, and `loadTestsFromFile` to load tests from the
non-module files selected by `wantFile`.
* The builtin attrib plugin implements `wantFunction` and
`wantMethod` so that it can reject tests that don't match the
specified attributes.
Handling errors
===============
To alter error handling behavior -- for instance to catch a
certain class of exception and handle it differently from the
normal error or failure handling -- you should subclass
`ErrorClassPlugin`. See the documentation for `ErrorClassPlugin`_ for
more details.
Examples:
* The builtin skip and deprecated plugins are ErrorClass plugins.
Preparing test objects
======================
To alter, get a handle on, or replace test framework objects such
as the loader, result, runner, and test cases, use the appropriate
prepare methods. The simplest reason to use prepare is if you need
to use an object yourself. For example, the isolate plugin
implements `prepareTestLoader` so that it can use the test loader
later on to load tests. If you return a value from a prepare
method, that value will be used in place of the loader, result,
runner or test case, respectively. When replacing test cases, be
aware that you are replacing the entire test case -- including the
whole `run(result)` method of the `unittest.TestCase` -- so if you
want normal unittest test result reporting, you must implement the
same calls to result as `unittest.TestCase.run`.
Examples:
* The builtin isolate plugin implements `prepareTestLoader` but
does not replace the test loader.
* The builtin profile plugin implements `prepareTest` and does
replace the top-level test case by returning the case wrapped in
the profiler function.
Watching or reporting on tests
==============================
To record information about tests or other modules imported during
the testing process, output additional reports, or entirely change
test report output, implement any of the methods outlined below that
correspond to TextTestResult methods.
Examples:
* The builtin cover plugin implements `begin` and `report` to
capture and report code coverage metrics for all or selected modules
loaded during testing.
* The builtin profile plugin implements `begin`, `prepareTest` and
`report` to record and output profiling information. In this
case, the plugin's `prepareTest` method constructs a function that
runs the test through the hotshot profiler's runcall() method.
"""
def __new__(cls, *arg, **kw):
raise TypeError("IPluginInterface class is for documentation only")
def addOptions(self, parser, env=os.environ):
"""Called to allow plugin to register command line
options with the parser.
Do *not* return a value from this method unless you want to stop
all other plugins from setting their options.
.. Note:: DEPRECATED -- implement `options` instead.
"""
pass
add_options = addOptions
add_options.deprecated = True
def addDeprecated(self, test):
"""Called when a deprecated test is seen. DO NOT return a value
unless you want to stop other plugins from seeing the deprecated
test.
.. Note:: DEPRECATED -- check error class in addError instead
:Parameters:
test : `nose.case.Test`_
the test case
"""
pass
addDeprecated.deprecated = True
def addError(self, test, err):
"""Called when a test raises an uncaught exception. DO NOT return a
value unless you want to stop other plugins from seeing that the
test has raised an error.
:Parameters:
test : `nose.case.Test`_
the test case
err : 3-tuple
sys.exc_info() tuple
capt : string
Captured output, if any
.. Note:: DEPRECATED: this parameter will not be passed
"""
pass
addError.changed = True
def addFailure(self, test, err):
"""Called when a test fails. DO NOT return a value unless you
want to stop other plugins from seeing that the test has failed.
:Parameters:
test : `nose.case.Test`_
the test case
err : 3-tuple
sys.exc_info() tuple
capt : string
Captured output, if any.
.. Note:: DEPRECATED: this parameter will not be passed
tb_info : string
Introspected traceback info, if any
.. Note:: DEPRECATED: this parameter will not be passed
"""
pass
addFailure.changed = True
def addSkip(self, test):
"""Called when a test is skipped. DO NOT return a value unless
you want to stop other plugins from seeing the skipped test.
.. Note:: DEPRECATED -- check error class in addError instead
:Parameters:
test : `nose.case.Test`_
the test case
"""
pass
addSkip.deprecated = True
def addSuccess(self, test):
"""Called when a test passes. DO NOT return a value unless you
want to stop other plugins from seeing the passing test.
:Parameters:
test : `nose.case.Test`_
the test case
capt : string
Captured output, if any.
.. Note:: DEPRECATED: this parameter will not be passed
"""
pass
addSuccess.changed = True
def afterContext(self):
"""Called after a context (generally a module) has been
lazy-loaded, imported, setup, had its tests loaded and
executed, and torn down.
"""
pass
afterContext._new = True
def afterDirectory(self, path):
"""Called after all tests have been loaded from directory at path
and run.
:Parameters:
path : string
the directory that has finished processing
"""
pass
afterDirectory._new = True
def afterImport(self, filename, module):
"""Called after module is imported from filename. afterImport
is called even if the import failed.
:Parameters:
filename : string
The file that was loaded
module : string
The name of the module
"""
pass
afterImport._new = True
def afterTest(self, test):
"""Called after the test has been run and the result recorded
(after stopTest).
:Parameters:
test : `nose.case.Test`_
the test case
"""
pass
afterTest._new = True
def beforeContext(self):
"""Called before a context (generally a module) is
examined. Since the context is not yet loaded, plugins don't
get to know what the context is; so any context operations
should use a stack that is pushed in `beforeContext` and popped
in `afterContext` to ensure they operate symmetrically.
`beforeContext` and `afterContext` are mainly
useful for tracking and restoring global state around possible
changes from within a context, whatever the context may be. If
you need to operate on contexts themselves, see `startContext`
and `stopContext`, which are passed the context in question, but
are called after it has been loaded (imported in the module
case).
"""
pass
beforeContext._new = True
def beforeDirectory(self, path):
"""Called before tests are loaded from directory at path.
:Parameters:
path : string
the directory that is about to be processed
"""
pass
beforeDirectory._new = True
def beforeImport(self, filename, module):
"""Called before module is imported from filename.
:Parameters:
filename : string
The file that will be loaded
module : string
The name of the module found in file
"""
beforeImport._new = True
def beforeTest(self, test):
"""Called before the test is run (before startTest).
:Parameters:
test : `nose.case.Test`_
the test case
"""
pass
beforeTest._new = True
def begin(self):
"""Called before any tests are collected or run. Use this to
perform any setup needed before testing begins.
"""
pass
def configure(self, options, conf):
"""Called after the command line has been parsed, with the
parsed options and the config container. Here, implement any
config storage or changes to state or operation that are set
by command line options.
Do *not* return a value from this method unless you want to
stop all other plugins from being configured.
"""
pass
def finalize(self, result):
"""Called after all report output, including output from all
plugins, has been sent to the stream. Use this to print final
test results or perform final cleanup. Return None to allow
other plugins to continue printing, any other value to stop
them.
.. Note:: When tests are run under a test runner other than
`nose.core.TextTestRunner`_, for example when tests are run
via ``python setup.py test``, this method may be called
**before** the default report output is sent.
"""
pass
def describeTest(self, test):
"""Return a test description. Called by
`nose.case.Test.shortDescription`.
:Parameters:
test : `nose.case.Test`_
the test case
"""
pass
describeTest._new = True
def formatError(self, test, err):
"""Called in result.addError, before plugin.addError. If you
want to replace or modify the error tuple, return a new error
tuple.
:Parameters:
test : `nose.case.Test`_
the test case
err : 3-tuple
sys.exc_info() tuple
"""
pass
formatError._new = True
formatError.chainable = True
# test arg is not chainable
formatError.static_args = (True, False)
def formatFailure(self, test, err):
"""Called in result.addFailure, before plugin.addFailure. If you
want to replace or modify the error tuple, return a new error
tuple. Since this method is chainable, you must return the
test as well, so you you'll return something like::
return (test, err)
:Parameters:
test : `nose.case.Test`_
the test case
err : 3-tuple
sys.exc_info() tuple
"""
pass
formatFailure._new = True
formatFailure.chainable = True
# test arg is not chainable
formatFailure.static_args = (True, False)
def handleError(self, test, err):
"""Called on addError. To handle the error yourself and prevent normal
error processing, return a true value.
:Parameters:
test : `nose.case.Test`_
the test case
err : 3-tuple
sys.exc_info() tuple
"""
pass
handleError._new = True
def handleFailure(self, test, err):
"""Called on addFailure. To handle the failure yourself and
prevent normal failure processing, return a true value.
:Parameters:
test : `nose.case.Test`_
the test case
err : 3-tuple
sys.exc_info() tuple
"""
pass
handleFailure._new = True
def loadTestsFromDir(self, path):
"""Return iterable of tests from a directory. May be a
generator. Each item returned must be a runnable
unittest.TestCase (or subclass) instance or suite instance.
Return None if your plugin cannot collect any tests from
directory.
:Parameters:
path : string
The path to the directory.
"""
pass
loadTestsFromDir.generative = True
loadTestsFromDir._new = True
def loadTestsFromModule(self, module):
"""Return iterable of tests in a module. May be a
generator. Each item returned must be a runnable
unittest.TestCase (or subclass) instance.
Return None if your plugin cannot
collect any tests from module.
:Parameters:
module : python module
The module object
"""
pass
loadTestsFromModule.generative = True
def loadTestsFromName(self, name, module=None, importPath=None):
"""Return tests in this file or module. Return None if you are not able
to load any tests, or an iterable if you are. May be a
generator.
:Parameters:
name : string
The test name. May be a file or module name plus a test
callable. Use split_test_name to split into parts. Or it might
be some crazy name of your own devising, in which case, do
whatever you want.
module : python module
Module from which the name is to be loaded
importPath :
Path from which file (must be a python module) was found
.. Note:: DEPRECATED: this argument will NOT be passed.
"""
pass
loadTestsFromName.generative = True
def loadTestsFromNames(self, names, module=None):
"""Return a tuple of (tests loaded, remaining names). Return
None if you are not able to load any tests. Multiple plugins
may implement loadTestsFromNames; the remaining name list from
each will be passed to the next as input.
:Parameters:
names : iterable
List of test names.
module : python module
Module from which the names are to be loaded
"""
pass
loadTestsFromNames._new = True
loadTestsFromNames.chainable = True
def loadTestsFromFile(self, filename):
"""Return tests in this file. Return None if you are not
interested in loading any tests, or an iterable if you are and
can load some. May be a generator. *If you are interested in
loading tests from the file and encounter no errors, but find
no tests, yield False or return [False].*
.. Note:: This method replaces loadTestsFromPath from the 0.9
API.
:Parameters:
filename : string
The full path to the file or directory.
"""
pass
loadTestsFromFile.generative = True
loadTestsFromFile._new = True
def loadTestsFromPath(self, path):
"""
.. Note:: DEPRECATED -- use loadTestsFromFile instead
"""
pass
loadTestsFromPath.deprecated = True
def loadTestsFromTestCase(self, cls):
"""Return tests in this test case class. Return None if you are
not able to load any tests, or an iterable if you are. May be a
generator.
:Parameters:
cls : class
The test case class. Must be subclass of unittest.TestCase.
"""
pass
loadTestsFromTestCase.generative = True
def loadTestsFromTestClass(self, cls):
"""Return tests in this test class. Class will *not* be a
unittest.TestCase subclass. Return None if you are not able to
load any tests, an iterable if you are. May be a generator.
:Parameters:
cls : class
The test class. Must NOT be subclass of unittest.TestCase.
"""
pass
loadTestsFromTestClass._new = True
loadTestsFromTestClass.generative = True
def makeTest(self, obj, parent):
"""Given an object and its parent, return or yield one or more
test cases. Each test must be a unittest.TestCase (or subclass)
instance. This is called before default test loading to allow
plugins to load an alternate test case or cases for an
object. May be a generator.
:Parameters:
obj : any object
The object to be made into a test
parent : class, module or other object
The parent of obj (eg, for a method, the class)
"""
pass
makeTest._new = True
makeTest.generative = True
def options(self, parser, env=os.environ):
"""Called to allow plugin to register command line
options with the parser.
Do *not* return a value from this method unless you want to stop
all other plugins from setting their options.
"""
pass
options._new = True
def prepareTest(self, test):
"""Called before the test is run by the test runner. Please
note the article *the* in the previous sentence: prepareTest
is called *only once*, and is passed the test case or test
suite that the test runner will execute. It is *not* called
for each individual test case. If you return a non-None value,
that return value will be run as the test. Use this hook to
wrap or decorate the test with another function. If you need
to modify or wrap individual test cases, use `prepareTestCase`
instead.
:Parameters:
test : `nose.case.Test`_
the test case
"""
pass
def prepareTestCase(self, test):
"""Prepare or wrap an individual test case. Called before
execution of the test. The test passed here is a
nose.case.Test instance; the case to be executed is in the
test attribute of the passed case. To modify the test to be
run, you should return a callable that takes one argument (the
test result object) -- it is recommended that you *do not*
side-effect the nose.case.Test instance you have been passed.
Keep in mind that when you replace the test callable you are
replacing the run() method of the test case -- including the
exception handling and result calls, etc.
:Parameters:
test : `nose.case.Test`_
the test case
"""
pass
prepareTestCase._new = True
def prepareTestLoader(self, loader):
"""Called before tests are loaded. To replace the test loader,
return a test loader. To allow other plugins to process the
test loader, return None. Only one plugin may replace the test
loader. Only valid when using nose.TestProgram.
:Parameters:
loader : `nose.loader.TestLoader` or other loader instance
the test loader
"""
pass
prepareTestLoader._new = True
def prepareTestResult(self, result):
"""Called before the first test is run. To use a different
test result handler for all tests than the given result,
return a test result handler. NOTE however that this handler
will only be seen by tests, that is, inside of the result
proxy system. The TestRunner and TestProgram -- whether nose's
or other -- will continue to see the original result
handler. For this reason, it is usually better to monkeypatch
the result (for instance, if you want to handle some
exceptions in a unique way). Only one plugin may replace the
result, but many may monkeypatch it. If you want to
monkeypatch and stop other plugins from doing so, monkeypatch
and return the patched result.
:Parameters:
result : `nose.result.TextTestResult` or other result instance
the test result
"""
pass
prepareTestResult._new = True
def prepareTestRunner(self, runner):
"""Called before tests are run. To replace the test runner,
return a test runner. To allow other plugins to process the
test runner, return None. Only valid when using nose.TestProgram.
:Parameters:
runner : `nose.core.TextTestRunner` or other runner instance
the test runner
"""
pass
prepareTestRunner._new = True
def report(self, stream):
"""Called after all error output has been printed. Print your
plugin's report to the provided stream. Return None to allow
other plugins to print reports, any other value to stop them.
:Parameters:
stream : file-like object
stream object; send your output here
"""
pass
def setOutputStream(self, stream):
"""Called before test output begins. To direct test output to a
new stream, return a stream object, which must implement a
`write(msg)` method. If you only want to note the stream, not
capture or redirect it, then return None.
:Parameters:
stream : file-like object
the original output stream
"""
def startContext(self, context):
"""Called before context setup and the running of tests in the
context. Note that tests have already been *loaded* from the
context before this call.
:Parameters:
context : module, class or other object
the context about to be setup. May be a module or class, or any
other object that contains tests.
"""
pass
startContext._new = True
def startTest(self, test):
"""Called before each test is run. DO NOT return a value unless
you want to stop other plugins from seeing the test start.
:Parameters:
test : `nose.case.Test`_
the test case
"""
pass
def stopContext(self, context):
"""Called after the tests in a context have run and the
context has been torn down.
:Parameters:
context : module, class or other object
the context that has just been torn down.
"""
pass
stopContext._new = True
def stopTest(self, test):
"""Called after each test is run. DO NOT return a value unless
you want to stop other plugins from seeing that the test has stopped.
:Parameters:
test : `nose.case.Test`_
the test case
"""
pass
def testName(self, test):
"""Return a short test name. Called by `nose.case.Test.__str__`.
:Parameters:
test : `nose.case.Test`_
the test case
"""
pass
testName._new = True
def wantClass(self, cls):
"""Return true if you want the main test selector to collect
tests from this class, false if you don't, and None if you don't
care.
:Parameters:
cls : class
The class being examined by the selector
"""
pass
def wantDirectory(self, dirname):
"""Return true if you want test collection to descend into this
directory, false if you do not, and None if you don't care.
:Parameters:
dirname : string
Full path to directory being examined by the selector
"""
pass
def wantFile(self, file):
"""Return true if you want to collect tests from this file,
false if you do not and None if you don't care.
Change from 0.9: The optional package parameter is no longer passed.
:Parameters:
file : string
Full path to file being examined by the selector
"""
pass
def wantFunction(self, function):
"""Return true to collect this function as a test, false to
prevent it from being collected, and None if you don't care.
:Parameters:
function : function
The function object being examined by the selector
"""
pass
def wantMethod(self, method):
"""Return true to collect this method as a test, false to
prevent it from being collected, and None if you don't care.
:Parameters:
method : unbound method
The method object being examined by the selector
"""
pass
def wantModule(self, module):
"""Return true if you want to collection to descend into this
module, false to prevent the collector from descending into the
module, and None if you don't care.
:Parameters:
module : python module
The module object being examined by the selector
"""
pass
def wantModuleTests(self, module):
"""
.. Note:: DEPRECATED -- this method will not be called, it has
been folded into wantModule.
"""
pass
wantModuleTests.deprecated = True