"""Attribute selector plugin. Oftentimes when testing you will want to select tests based on criteria rather then simply by filename. For example, you might want to run all tests except for the slow ones. You can do this with the Attribute selector plugin by setting attributes on your test methods. Here is an example: .. code-block:: python def test_big_download(): import urllib # commence slowness... test_big_download.slow = 1 Once you've assigned an attribute ``slow = 1`` you can exclude that test and all other tests having the slow attribute by running :: $ nosetests -a '!slow' There is also a decorator available for you that will set attributes. Here's how to set ``slow=1`` like above with the decorator: .. code-block:: python from nose.plugins.attrib import attr @attr('slow') def test_big_download(): import urllib # commence slowness... And here's how to set an attribute with a specific value: .. code-block:: python from nose.plugins.attrib import attr @attr(speed='slow') def test_big_download(): import urllib # commence slowness... This test could be run with :: $ nosetests -a speed=slow In Python 2.6 and higher, ``@attr`` can be used on a class to set attributes on all its test methods at once. For example: .. code-block:: python from nose.plugins.attrib import attr @attr(speed='slow') class MyTestCase: def test_long_integration(self): pass def test_end_to_end_something(self): pass Below is a reference to the different syntaxes available. Simple syntax ------------- Examples of using the ``-a`` and ``--attr`` options: * ``nosetests -a status=stable`` Only runs tests with attribute "status" having value "stable" * ``nosetests -a priority=2,status=stable`` Runs tests having both attributes and values * ``nosetests -a priority=2 -a slow`` Runs tests that match either attribute * ``nosetests -a tags=http`` If a test's ``tags`` attribute was a list and it contained the value ``http`` then it would be run * ``nosetests -a slow`` Runs tests with the attribute ``slow`` if its value does not equal False (False, [], "", etc...) * ``nosetests -a '!slow'`` Runs tests that do NOT have the attribute ``slow`` or have a ``slow`` attribute that is equal to False **NOTE**: if your shell (like bash) interprets '!' as a special character make sure to put single quotes around it. Expression Evaluation --------------------- Examples using the ``-A`` and ``--eval-attr`` options: * ``nosetests -A "not slow"`` Evaluates the Python expression "not slow" and runs the test if True * ``nosetests -A "(priority > 5) and not slow"`` Evaluates a complex Python expression and runs the test if True """ import inspect import logging import os import sys from inspect import isfunction from nose.plugins.base import Plugin from nose.util import tolist log = logging.getLogger('nose.plugins.attrib') compat_24 = sys.version_info >= (2, 4) def attr(*args, **kwargs): """Decorator that adds attributes to classes or functions for use with the Attribute (-a) plugin. """ def wrap_ob(ob): for name in args: setattr(ob, name, True) for name, value in kwargs.items(): setattr(ob, name, value) return ob return wrap_ob def get_method_attr(method, cls, attr_name, default = False): """Look up an attribute on a method/ function. If the attribute isn't found there, looking it up in the method's class, if any. """ Missing = object() value = getattr(method, attr_name, Missing) if value is Missing and cls is not None: value = getattr(cls, attr_name, Missing) if value is Missing: return default return value class ContextHelper: """Object that can act as context dictionary for eval and looks up names as attributes on a method/ function and its class. """ def __init__(self, method, cls): self.method = method self.cls = cls def __getitem__(self, name): return get_method_attr(self.method, self.cls, name) class AttributeSelector(Plugin): """Selects test cases to be run based on their attributes. """ def __init__(self): Plugin.__init__(self) self.attribs = [] def options(self, parser, env): """Register command line options""" parser.add_option("-a", "--attr", dest="attr", action="append", default=env.get('NOSE_ATTR'), metavar="ATTR", help="Run only tests that have attributes " "specified by ATTR [NOSE_ATTR]") # disable in < 2.4: eval can't take needed args if compat_24: parser.add_option("-A", "--eval-attr", dest="eval_attr", metavar="EXPR", action="append", default=env.get('NOSE_EVAL_ATTR'), help="Run only tests for whose attributes " "the Python expression EXPR evaluates " "to True [NOSE_EVAL_ATTR]") def configure(self, options, config): """Configure the plugin and system, based on selected options. attr and eval_attr may each be lists. self.attribs will be a list of lists of tuples. In that list, each list is a group of attributes, all of which must match for the rule to match. """ self.attribs = [] # handle python eval-expression parameter if compat_24 and options.eval_attr: eval_attr = tolist(options.eval_attr) for attr in eval_attr: # "<python expression>" # -> eval(expr) in attribute context must be True def eval_in_context(expr, obj, cls): return eval(expr, None, ContextHelper(obj, cls)) self.attribs.append([(attr, eval_in_context)]) # attribute requirements are a comma separated list of # 'key=value' pairs if options.attr: std_attr = tolist(options.attr) for attr in std_attr: # all attributes within an attribute group must match attr_group = [] for attrib in attr.strip().split(","): # don't die on trailing comma if not attrib: continue items = attrib.split("=", 1) if len(items) > 1: # "name=value" # -> 'str(obj.name) == value' must be True key, value = items else: key = items[0] if key[0] == "!": # "!name" # 'bool(obj.name)' must be False key = key[1:] value = False else: # "name" # -> 'bool(obj.name)' must be True value = True attr_group.append((key, value)) self.attribs.append(attr_group) if self.attribs: self.enabled = True def validateAttrib(self, method, cls = None): """Verify whether a method has the required attributes The method is considered a match if it matches all attributes for any attribute group. .""" # TODO: is there a need for case-sensitive value comparison? any = False for group in self.attribs: match = True for key, value in group: attr = get_method_attr(method, cls, key) if callable(value): if not value(key, method, cls): match = False break elif value is True: # value must exist and be True if not bool(attr): match = False break elif value is False: # value must not exist or be False if bool(attr): match = False break elif type(attr) in (list, tuple): # value must be found in the list attribute if not str(value).lower() in [str(x).lower() for x in attr]: match = False break else: # value must match, convert to string and compare if (value != attr and str(value).lower() != str(attr).lower()): match = False break any = any or match if any: # not True because we don't want to FORCE the selection of the # item, only say that it is acceptable return None return False def wantFunction(self, function): """Accept the function if its attributes match. """ return self.validateAttrib(function) def wantMethod(self, method): """Accept the method if its attributes match. """ try: cls = method.__self__.__class__ except AttributeError: return False return self.validateAttrib(method, cls)