Source code for django.test.utils

import collections
import logging
import re
import sys
import time
import warnings
from contextlib import contextmanager
from functools import wraps
from io import StringIO
from itertools import chain
from types import SimpleNamespace
from unittest import TestCase, skipIf, skipUnless
from xml.dom.minidom import Node, parseString

from django.apps import apps
from django.apps.registry import Apps
from django.conf import UserSettingsHolder, settings
from django.core import mail
from django.core.exceptions import ImproperlyConfigured
from django.core.signals import request_started
from django.db import DEFAULT_DB_ALIAS, connections, reset_queries
from django.db.models.options import Options
from django.template import Template
from django.test.signals import setting_changed, template_rendered
from django.urls import get_script_prefix, set_script_prefix
from django.utils.translation import deactivate

    import jinja2
except ImportError:
    jinja2 = None

__all__ = (
    'Approximate', 'ContextList', 'isolate_lru_cache', 'get_runner',
    'modify_settings', 'override_settings',
    'setup_test_environment', 'teardown_test_environment',

TZ_SUPPORT = hasattr(time, 'tzset')

class Approximate:
    def __init__(self, val, places=7):
        self.val = val
        self.places = places

    def __repr__(self):
        return repr(self.val)

    def __eq__(self, other):
        if self.val == other:
            return True
        return round(abs(self.val - other), self.places) == 0

class ContextList(list):
    A wrapper that provides direct key access to context items contained
    in a list of context objects.
    def __getitem__(self, key):
        if isinstance(key, str):
            for subcontext in self:
                if key in subcontext:
                    return subcontext[key]
            raise KeyError(key)
            return super().__getitem__(key)

    def get(self, key, default=None):
            return self.__getitem__(key)
        except KeyError:
            return default

    def __contains__(self, key):
        except KeyError:
            return False
        return True

    def keys(self):
        Flattened keys of subcontexts.
        return set(chain.from_iterable(d for subcontext in self for d in subcontext))

def instrumented_test_render(self, context):
    An instrumented Template render method, providing a signal that can be
    intercepted by the test Client.
    template_rendered.send(sender=self, template=self, context=context)
    return self.nodelist.render(context)

class _TestState:

[docs]def setup_test_environment(debug=None): """ Perform global pre-test setup, such as installing the instrumented template renderer and setting the email backend to the locmem email backend. """ if hasattr(_TestState, 'saved_data'): # Executing this function twice would overwrite the saved values. raise RuntimeError( "setup_test_environment() was already called and can't be called " "again without first calling teardown_test_environment()." ) if debug is None: debug = settings.DEBUG saved_data = SimpleNamespace() _TestState.saved_data = saved_data saved_data.allowed_hosts = settings.ALLOWED_HOSTS # Add the default host of the test client. settings.ALLOWED_HOSTS = list(settings.ALLOWED_HOSTS) + ['testserver'] saved_data.debug = settings.DEBUG settings.DEBUG = debug saved_data.email_backend = settings.EMAIL_BACKEND settings.EMAIL_BACKEND = 'django.core.mail.backends.locmem.EmailBackend' saved_data.template_render = Template._render Template._render = instrumented_test_render mail.outbox = [] deactivate()
[docs]def teardown_test_environment(): """ Perform any global post-test teardown, such as restoring the original template renderer and restoring the email sending functions. """ saved_data = _TestState.saved_data settings.ALLOWED_HOSTS = saved_data.allowed_hosts settings.DEBUG = saved_data.debug settings.EMAIL_BACKEND = saved_data.email_backend Template._render = saved_data.template_render del _TestState.saved_data del mail.outbox
[docs]def setup_databases(verbosity, interactive, keepdb=False, debug_sql=False, parallel=0, **kwargs): """Create the test databases.""" test_databases, mirrored_aliases = get_unique_databases_and_mirrors() old_names = [] for signature, (db_name, aliases) in test_databases.items(): first_alias = None for alias in aliases: connection = connections[alias] old_names.append((connection, db_name, first_alias is None)) # Actually create the database for the first connection if first_alias is None: first_alias = alias connection.creation.create_test_db( verbosity=verbosity, autoclobber=not interactive, keepdb=keepdb, serialize=connection.settings_dict.get('TEST', {}).get('SERIALIZE', True), ) if parallel > 1: for index in range(parallel): connection.creation.clone_test_db( suffix=str(index + 1), verbosity=verbosity, keepdb=keepdb, ) # Configure all other connections as mirrors of the first one else: connections[alias].creation.set_as_test_mirror(connections[first_alias].settings_dict) # Configure the test mirrors. for alias, mirror_alias in mirrored_aliases.items(): connections[alias].creation.set_as_test_mirror( connections[mirror_alias].settings_dict) if debug_sql: for alias in connections: connections[alias].force_debug_cursor = True return old_names
def dependency_ordered(test_databases, dependencies): """ Reorder test_databases into an order that honors the dependencies described in TEST[DEPENDENCIES]. """ ordered_test_databases = [] resolved_databases = set() # Maps db signature to dependencies of all its aliases dependencies_map = {} # Check that no database depends on its own alias for sig, (_, aliases) in test_databases: all_deps = set() for alias in aliases: all_deps.update(dependencies.get(alias, [])) if not all_deps.isdisjoint(aliases): raise ImproperlyConfigured( "Circular dependency: databases %r depend on each other, " "but are aliases." % aliases ) dependencies_map[sig] = all_deps while test_databases: changed = False deferred = [] # Try to find a DB that has all its dependencies met for signature, (db_name, aliases) in test_databases: if dependencies_map[signature].issubset(resolved_databases): resolved_databases.update(aliases) ordered_test_databases.append((signature, (db_name, aliases))) changed = True else: deferred.append((signature, (db_name, aliases))) if not changed: raise ImproperlyConfigured("Circular dependency in TEST[DEPENDENCIES]") test_databases = deferred return ordered_test_databases def get_unique_databases_and_mirrors(): """ Figure out which databases actually need to be created. Deduplicate entries in DATABASES that correspond the same database or are configured as test mirrors. Return two values: - test_databases: ordered mapping of signatures to (name, list of aliases) where all aliases share the same underlying database. - mirrored_aliases: mapping of mirror aliases to original aliases. """ mirrored_aliases = {} test_databases = {} dependencies = {} default_sig = connections[DEFAULT_DB_ALIAS].creation.test_db_signature() for alias in connections: connection = connections[alias] test_settings = connection.settings_dict['TEST'] if test_settings['MIRROR']: # If the database is marked as a test mirror, save the alias. mirrored_aliases[alias] = test_settings['MIRROR'] else: # Store a tuple with DB parameters that uniquely identify it. # If we have two aliases with the same values for that tuple, # we only need to create the test database once. item = test_databases.setdefault( connection.creation.test_db_signature(), (connection.settings_dict['NAME'], set()) ) item[1].add(alias) if 'DEPENDENCIES' in test_settings: dependencies[alias] = test_settings['DEPENDENCIES'] else: if alias != DEFAULT_DB_ALIAS and connection.creation.test_db_signature() != default_sig: dependencies[alias] = test_settings.get('DEPENDENCIES', [DEFAULT_DB_ALIAS]) test_databases = dependency_ordered(test_databases.items(), dependencies) test_databases = collections.OrderedDict(test_databases) return test_databases, mirrored_aliases
[docs]def teardown_databases(old_config, verbosity, parallel=0, keepdb=False): """Destroy all the non-mirror databases.""" for connection, old_name, destroy in old_config: if destroy: if parallel > 1: for index in range(parallel): connection.creation.destroy_test_db( suffix=str(index + 1), verbosity=verbosity, keepdb=keepdb, ) connection.creation.destroy_test_db(old_name, verbosity, keepdb)
def get_runner(settings, test_runner_class=None): if not test_runner_class: test_runner_class = settings.TEST_RUNNER test_path = test_runner_class.split('.') # Allow for relative paths if len(test_path) > 1: test_module_name = '.'.join(test_path[:-1]) else: test_module_name = '.' test_module = __import__(test_module_name, {}, {}, test_path[-1]) test_runner = getattr(test_module, test_path[-1]) return test_runner class TestContextDecorator: """ A base class that can either be used as a context manager during tests or as a test function or unittest.TestCase subclass decorator to perform temporary alterations. `attr_name`: attribute assigned the return value of enable() if used as a class decorator. `kwarg_name`: keyword argument passing the return value of enable() if used as a function decorator. """ def __init__(self, attr_name=None, kwarg_name=None): self.attr_name = attr_name self.kwarg_name = kwarg_name def enable(self): raise NotImplementedError def disable(self): raise NotImplementedError def __enter__(self): return self.enable() def __exit__(self, exc_type, exc_value, traceback): self.disable() def decorate_class(self, cls): if issubclass(cls, TestCase): decorated_setUp = cls.setUp decorated_tearDown = cls.tearDown def setUp(inner_self): context = self.enable() if self.attr_name: setattr(inner_self, self.attr_name, context) decorated_setUp(inner_self) def tearDown(inner_self): decorated_tearDown(inner_self) self.disable() cls.setUp = setUp cls.tearDown = tearDown return cls raise TypeError('Can only decorate subclasses of unittest.TestCase') def decorate_callable(self, func): @wraps(func) def inner(*args, **kwargs): with self as context: if self.kwarg_name: kwargs[self.kwarg_name] = context return func(*args, **kwargs) return inner def __call__(self, decorated): if isinstance(decorated, type): return self.decorate_class(decorated) elif callable(decorated): return self.decorate_callable(decorated) raise TypeError('Cannot decorate object of type %s' % type(decorated))
[docs]class override_settings(TestContextDecorator): """ Act as either a decorator or a context manager. If it's a decorator, take a function and return a wrapped function. If it's a contextmanager, use it with the ``with`` statement. In either event, entering/exiting are called before and after, respectively, the function/block is executed. """ def __init__(self, **kwargs): self.options = kwargs super().__init__() def enable(self): # Keep this code at the beginning to leave the settings unchanged # in case it raises an exception because INSTALLED_APPS is invalid. if 'INSTALLED_APPS' in self.options: try: apps.set_installed_apps(self.options['INSTALLED_APPS']) except Exception: apps.unset_installed_apps() raise override = UserSettingsHolder(settings._wrapped) for key, new_value in self.options.items(): setattr(override, key, new_value) self.wrapped = settings._wrapped settings._wrapped = override for key, new_value in self.options.items(): setting_changed.send(sender=settings._wrapped.__class__, setting=key, value=new_value, enter=True) def disable(self): if 'INSTALLED_APPS' in self.options: apps.unset_installed_apps() settings._wrapped = self.wrapped del self.wrapped for key in self.options: new_value = getattr(settings, key, None) setting_changed.send(sender=settings._wrapped.__class__, setting=key, value=new_value, enter=False) def save_options(self, test_func): if test_func._overridden_settings is None: test_func._overridden_settings = self.options else: # Duplicate dict to prevent subclasses from altering their parent. test_func._overridden_settings = dict( test_func._overridden_settings, **self.options) def decorate_class(self, cls): from django.test import SimpleTestCase if not issubclass(cls, SimpleTestCase): raise ValueError( "Only subclasses of Django SimpleTestCase can be decorated " "with override_settings") self.save_options(cls) return cls
[docs]class modify_settings(override_settings): """ Like override_settings, but makes it possible to append, prepend, or remove items instead of redefining the entire list. """ def __init__(self, *args, **kwargs): if args: # Hack used when instantiating from SimpleTestCase.setUpClass. assert not kwargs self.operations = args[0] else: assert not args self.operations = list(kwargs.items()) super(override_settings, self).__init__() def save_options(self, test_func): if test_func._modified_settings is None: test_func._modified_settings = self.operations else: # Duplicate list to prevent subclasses from altering their parent. test_func._modified_settings = list( test_func._modified_settings) + self.operations def enable(self): self.options = {} for name, operations in self.operations: try: # When called from SimpleTestCase.setUpClass, values may be # overridden several times; cumulate changes. value = self.options[name] except KeyError: value = list(getattr(settings, name, [])) for action, items in operations.items(): # items my be a single value or an iterable. if isinstance(items, str): items = [items] if action == 'append': value = value + [item for item in items if item not in value] elif action == 'prepend': value = [item for item in items if item not in value] + value elif action == 'remove': value = [item for item in value if item not in items] else: raise ValueError("Unsupported action: %s" % action) self.options[name] = value super().enable()
class override_system_checks(TestContextDecorator): """ Act as a decorator. Override list of registered system checks. Useful when you override `INSTALLED_APPS`, e.g. if you exclude `auth` app, you also need to exclude its system checks. """ def __init__(self, new_checks, deployment_checks=None): from django.core.checks.registry import registry self.registry = registry self.new_checks = new_checks self.deployment_checks = deployment_checks super().__init__() def enable(self): self.old_checks = self.registry.registered_checks self.registry.registered_checks = set() for check in self.new_checks: self.registry.register(check, *getattr(check, 'tags', ())) self.old_deployment_checks = self.registry.deployment_checks if self.deployment_checks is not None: self.registry.deployment_checks = set() for check in self.deployment_checks: self.registry.register(check, *getattr(check, 'tags', ()), deploy=True) def disable(self): self.registry.registered_checks = self.old_checks self.registry.deployment_checks = self.old_deployment_checks def compare_xml(want, got): """ Try to do a 'xml-comparison' of want and got. Plain string comparison doesn't always work because, for example, attribute ordering should not be important. Ignore comment nodes and leading and trailing whitespace. Based on """ _norm_whitespace_re = re.compile(r'[ \t\n][ \t\n]+') def norm_whitespace(v): return _norm_whitespace_re.sub(' ', v) def child_text(element): return ''.join( for c in element.childNodes if c.nodeType == Node.TEXT_NODE) def children(element): return [c for c in element.childNodes if c.nodeType == Node.ELEMENT_NODE] def norm_child_text(element): return norm_whitespace(child_text(element)) def attrs_dict(element): return dict(element.attributes.items()) def check_element(want_element, got_element): if want_element.tagName != got_element.tagName: return False if norm_child_text(want_element) != norm_child_text(got_element): return False if attrs_dict(want_element) != attrs_dict(got_element): return False want_children = children(want_element) got_children = children(got_element) if len(want_children) != len(got_children): return False for want, got in zip(want_children, got_children): if not check_element(want, got): return False return True def first_node(document): for node in document.childNodes: if node.nodeType != Node.COMMENT_NODE: return node want = want.strip().replace('\\n', '\n') got = got.strip().replace('\\n', '\n') # If the string is not a complete xml document, we may need to add a # root element. This allow us to compare fragments, like "<foo/><bar/>" if not want.startswith('<?xml'): wrapper = '<root>%s</root>' want = wrapper % want got = wrapper % got # Parse the want and got strings, and compare the parsings. want_root = first_node(parseString(want)) got_root = first_node(parseString(got)) return check_element(want_root, got_root) def str_prefix(s): return s % {'_': ''} class CaptureQueriesContext: """ Context manager that captures queries executed by the specified connection. """ def __init__(self, connection): self.connection = connection def __iter__(self): return iter(self.captured_queries) def __getitem__(self, index): return self.captured_queries[index] def __len__(self): return len(self.captured_queries) @property def captured_queries(self): return self.connection.queries[self.initial_queries:self.final_queries] def __enter__(self): self.force_debug_cursor = self.connection.force_debug_cursor self.connection.force_debug_cursor = True # Run any initialization queries if needed so that they won't be # included as part of the count. self.connection.ensure_connection() self.initial_queries = len(self.connection.queries_log) self.final_queries = None request_started.disconnect(reset_queries) return self def __exit__(self, exc_type, exc_value, traceback): self.connection.force_debug_cursor = self.force_debug_cursor request_started.connect(reset_queries) if exc_type is not None: return self.final_queries = len(self.connection.queries_log) class ignore_warnings(TestContextDecorator): def __init__(self, **kwargs): self.ignore_kwargs = kwargs if 'message' in self.ignore_kwargs or 'module' in self.ignore_kwargs: self.filter_func = warnings.filterwarnings else: self.filter_func = warnings.simplefilter super().__init__() def enable(self): self.catch_warnings = warnings.catch_warnings() self.catch_warnings.__enter__() self.filter_func('ignore', **self.ignore_kwargs) def disable(self): self.catch_warnings.__exit__(*sys.exc_info()) @contextmanager def patch_logger(logger_name, log_level, log_kwargs=False): """ Context manager that takes a named logger and the logging level and provides a simple mock-like list of messages received """ calls = [] def replacement(msg, *args, **kwargs): call = msg % args calls.append((call, kwargs) if log_kwargs else call) logger = logging.getLogger(logger_name) orig = getattr(logger, log_level) setattr(logger, log_level, replacement) try: yield calls finally: setattr(logger, log_level, orig) # On OSes that don't provide tzset (Windows), we can't set the timezone # in which the program runs. As a consequence, we must skip tests that # don't enforce a specific timezone (with timezone.override or equivalent), # or attempt to interpret naive datetimes in the default timezone. requires_tz_support = skipUnless( TZ_SUPPORT, "This test relies on the ability to run a program in an arbitrary " "time zone, but your operating system isn't able to do that." ) @contextmanager def extend_sys_path(*paths): """Context manager to temporarily add paths to sys.path.""" _orig_sys_path = sys.path[:] sys.path.extend(paths) try: yield finally: sys.path = _orig_sys_path @contextmanager def isolate_lru_cache(lru_cache_object): """Clear the cache of an LRU cache object on entering and exiting.""" lru_cache_object.cache_clear() try: yield finally: lru_cache_object.cache_clear() @contextmanager def captured_output(stream_name): """Return a context manager used by captured_stdout/stdin/stderr that temporarily replaces the sys stream *stream_name* with a StringIO. Note: This function and the following ``captured_std*`` are copied from CPython's ```` module.""" orig_stdout = getattr(sys, stream_name) setattr(sys, stream_name, StringIO()) try: yield getattr(sys, stream_name) finally: setattr(sys, stream_name, orig_stdout) def captured_stdout(): """Capture the output of sys.stdout: with captured_stdout() as stdout: print("hello") self.assertEqual(stdout.getvalue(), "hello\n") """ return captured_output("stdout") def captured_stderr(): """Capture the output of sys.stderr: with captured_stderr() as stderr: print("hello", file=sys.stderr) self.assertEqual(stderr.getvalue(), "hello\n") """ return captured_output("stderr") def captured_stdin(): """Capture the input to sys.stdin: with captured_stdin() as stdin: stdin.write('hello\n') # call test code that consumes from sys.stdin captured = input() self.assertEqual(captured, "hello") """ return captured_output("stdin") @contextmanager def freeze_time(t): """ Context manager to temporarily freeze time.time(). This temporarily modifies the time function of the time module. Modules which import the time function directly (e.g. `from time import time`) won't be affected This isn't meant as a public API, but helps reduce some repetitive code in Django's test suite. """ _real_time = time.time time.time = lambda: t try: yield finally: time.time = _real_time def require_jinja2(test_func): """ Decorator to enable a Jinja2 template engine in addition to the regular Django template engine for a test or skip it if Jinja2 isn't available. """ test_func = skipIf(jinja2 is None, "this test requires jinja2")(test_func) test_func = override_settings(TEMPLATES=[{ 'BACKEND': 'django.template.backends.django.DjangoTemplates', 'APP_DIRS': True, }, { 'BACKEND': 'django.template.backends.jinja2.Jinja2', 'APP_DIRS': True, 'OPTIONS': {'keep_trailing_newline': True}, }])(test_func) return test_func class override_script_prefix(TestContextDecorator): """Decorator or context manager to temporary override the script prefix.""" def __init__(self, prefix): self.prefix = prefix super().__init__() def enable(self): self.old_prefix = get_script_prefix() set_script_prefix(self.prefix) def disable(self): set_script_prefix(self.old_prefix) class LoggingCaptureMixin: """ Capture the output from the 'django' logger and store it on the class's logger_output attribute. """ def setUp(self): self.logger = logging.getLogger('django') self.old_stream = self.logger.handlers[0].stream self.logger_output = StringIO() self.logger.handlers[0].stream = self.logger_output def tearDown(self): self.logger.handlers[0].stream = self.old_stream class isolate_apps(TestContextDecorator): """ Act as either a decorator or a context manager to register models defined in its wrapped context to an isolated registry. The list of installed apps the isolated registry should contain must be passed as arguments. Two optional keyword arguments can be specified: `attr_name`: attribute assigned the isolated registry if used as a class decorator. `kwarg_name`: keyword argument passing the isolated registry if used as a function decorator. """ def __init__(self, *installed_apps, **kwargs): self.installed_apps = installed_apps super().__init__(**kwargs) def enable(self): self.old_apps = Options.default_apps apps = Apps(self.installed_apps) setattr(Options, 'default_apps', apps) return apps def disable(self): setattr(Options, 'default_apps', self.old_apps) def tag(*tags): """Decorator to add tags to a test class or method.""" def decorator(obj): setattr(obj, 'tags', set(tags)) return obj return decorator
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