Fixed #14799 -- Provided a full solution for test database creation order problems. (b11c21d6) · Commits · Dom Sekotill / django

django/test/simple.py

+53 −13

Original line number	Diff line number	Diff line
		@@ -2,12 +2,21 @@ import sys
		import signal

		from django.conf import settings
		from django.core.exceptions import ImproperlyConfigured
		from django.db.models import get_app, get_apps
		from django.test import _doctest as doctest
		from django.test.utils import setup_test_environment, teardown_test_environment
		from django.test.testcases import OutputChecker, DocTestRunner, TestCase
		from django.utils import unittest

		try:
		all
		except NameError:
		from django.utils.itercompat import all


		__all__ = ('DjangoTestRunner', 'DjangoTestSuiteRunner', 'run_tests')

		# The module name for tests outside models.py
		TEST_MODULE = 'tests'

		@@ -183,6 +192,40 @@ def reorder_suite(suite, classes):
		bins[0].addTests(bins[i+1])
		return bins[0]

		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()
		while test_databases:
		changed = False
		deferred = []

		while test_databases:
		signature, aliases = test_databases.pop()
		dependencies_satisfied = True
		for alias in aliases:
		if alias in dependencies:
		if all(a in resolved_databases for a in dependencies[alias]):
		# all dependencies for this alias are satisfied
		dependencies.pop(alias)
		resolved_databases.add(alias)
		else:
		dependencies_satisfied = False
		else:
		resolved_databases.add(alias)

		if dependencies_satisfied:
		ordered_test_databases.append((signature, aliases))
		changed = True
		else:
		deferred.append((signature, aliases))

		if not changed:
		raise ImproperlyConfigured("Circular dependency in TEST_DEPENDENCIES")
		test_databases = deferred
		return ordered_test_databases

		class DjangoTestSuiteRunner(object):
		def __init__(self, verbosity=1, interactive=True, failfast=True, **kwargs):
		@@ -222,6 +265,7 @@ class DjangoTestSuiteRunner(object):
		# and which ones are test mirrors or duplicate entries in DATABASES
		mirrored_aliases = {}
		test_databases = {}
		dependencies = {}
		for alias in connections:
		connection = connections[alias]
		if connection.settings_dict['TEST_MIRROR']:
		@@ -239,20 +283,16 @@ class DjangoTestSuiteRunner(object):
		connection.settings_dict['NAME'],
		), []).append(alias)

		# Re-order the list of databases to create, making sure the default
		# database is first. Otherwise, creation order is semi-random (i.e.
		# dict ordering dependent).
		dbs_to_create = []
		for dbinfo, aliases in test_databases.items():
		if DEFAULT_DB_ALIAS in aliases:
		dbs_to_create.insert(0, (dbinfo, aliases))
		if 'TEST_DEPENDENCIES' in connection.settings_dict:
		dependencies[alias] = connection.settings_dict['TEST_DEPENDENCIES']
		else:
		dbs_to_create.append((dbinfo, aliases))
		if alias != 'default':
		dependencies[alias] = connection.settings_dict.get('TEST_DEPENDENCIES', ['default'])

		# Final pass -- actually create the databases.
		# Second pass -- actually create the databases.
		old_names = []
		mirrors = []
		for (host, port, engine, db_name), aliases in dbs_to_create:
		for (host, port, engine, db_name), aliases in dependency_ordered(test_databases.items(), dependencies):
		# Actually create the database for the first connection
		connection = connections[aliases[0]]
		old_names.append((connection, db_name, True))

docs/topics/testing.txt

+47 −0

Original line number	Diff line number	Diff line
		@@ -454,6 +454,53 @@ will be redirected to point at ``default``. As a result, writes to
		the same database, not because there is data replication between the
		two databases.

		.. _topics-testing-creation-dependencies:

		Controlling creation order for test databases
		~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

		.. versionadded:: 1.3

		By default, Django will always create the ``default`` database first.
		However, no guarantees are made on the creation order of any other
		databases in your test setup.

		If your database configuration requires a specific creation order, you
		can specify the dependencies that exist using the
		:setting:`TEST_DEPENDENCIES` setting. Consider the following
		(simplified) example database configuration::

		DATABASES = {
		'default': {
		# ... db settings
		TEST_DEPENDENCIES = ['diamonds']
		},
		'diamonds': {
		# ... db settings
		}
		'clubs': {
		# ... db settings
		TEST_DEPENDENCIES = ['diamonds']
		}
		'spades': {
		# ... db settings
		TEST_DEPENDENCIES = ['diamonds','hearts']
		}
		'hearts': {
		# ... db settings
		TEST_DEPENDENCIES = ['diamonds','clubs']
		}
		}

		Under this configuration, the ``diamonds`` database will be created first,
		as it is the only database alias without dependencies. The ``default``` and
		``clubs`` alias will be created next (although the order of creation of this
		pair is not guaranteed); then ``hearts``; and finally ``spades``.

		If there are any circular dependencies in the
		:setting:`TEST_DEPENDENCIES` definition, an ``ImproperlyConfigured``
		exception will be raised.

		Other test conditions
		---------------------

tests/regressiontests/test_runner/tests.py

+91 −0

Original line number	Diff line number	Diff line
		@@ -3,6 +3,7 @@ Tests for django test runner
		"""
		import StringIO

		from django.core.exceptions import ImproperlyConfigured
		from django.test import simple
		from django.utils import unittest

		@@ -27,3 +28,93 @@ class DjangoTestRunnerTests(unittest.TestCase):
		result = dtr.run(suite)
		self.assertEqual(1, result.testsRun)
		self.assertEqual(1, len(result.failures))

		class DependencyOrderingTests(unittest.TestCase):

		def test_simple_dependencies(self):
		raw = [
		('s1', ['alpha']),
		('s2', ['bravo']),
		('s3', ['charlie']),
		]
		dependencies = {
		'alpha': ['charlie'],
		'bravo': ['charlie'],
		}

		ordered = simple.dependency_ordered(raw, dependencies=dependencies)
		ordered_sigs = [sig for sig,aliases in ordered]

		self.assertIn('s1', ordered_sigs)
		self.assertIn('s2', ordered_sigs)
		self.assertIn('s3', ordered_sigs)
		self.assertLess(ordered_sigs.index('s3'), ordered_sigs.index('s1'))
		self.assertLess(ordered_sigs.index('s3'), ordered_sigs.index('s2'))

		def test_chained_dependencies(self):
		raw = [
		('s1', ['alpha']),
		('s2', ['bravo']),
		('s3', ['charlie']),
		]
		dependencies = {
		'alpha': ['bravo'],
		'bravo': ['charlie'],
		}

		ordered = simple.dependency_ordered(raw, dependencies=dependencies)
		ordered_sigs = [sig for sig,aliases in ordered]

		self.assertIn('s1', ordered_sigs)
		self.assertIn('s2', ordered_sigs)
		self.assertIn('s3', ordered_sigs)

		# Explicit dependencies
		self.assertLess(ordered_sigs.index('s2'), ordered_sigs.index('s1'))
		self.assertLess(ordered_sigs.index('s3'), ordered_sigs.index('s2'))

		# Implied dependencies
		self.assertLess(ordered_sigs.index('s3'), ordered_sigs.index('s1'))

		def test_multiple_dependencies(self):
		raw = [
		('s1', ['alpha']),
		('s2', ['bravo']),
		('s3', ['charlie']),
		('s4', ['delta']),
		]
		dependencies = {
		'alpha': ['bravo','delta'],
		'bravo': ['charlie'],
		'delta': ['charlie'],
		}

		ordered = simple.dependency_ordered(raw, dependencies=dependencies)
		ordered_sigs = [sig for sig,aliases in ordered]

		self.assertIn('s1', ordered_sigs)
		self.assertIn('s2', ordered_sigs)
		self.assertIn('s3', ordered_sigs)
		self.assertIn('s4', ordered_sigs)

		# Explicit dependencies
		self.assertLess(ordered_sigs.index('s2'), ordered_sigs.index('s1'))
		self.assertLess(ordered_sigs.index('s4'), ordered_sigs.index('s1'))
		self.assertLess(ordered_sigs.index('s3'), ordered_sigs.index('s2'))
		self.assertLess(ordered_sigs.index('s3'), ordered_sigs.index('s4'))

		# Implicit dependencies
		self.assertLess(ordered_sigs.index('s3'), ordered_sigs.index('s1'))

		def test_circular_dependencies(self):
		raw = [
		('s1', ['alpha']),
		('s2', ['bravo']),
		]
		dependencies = {
		'bravo': ['alpha'],
		'alpha': ['bravo'],
		}

		self.assertRaises(ImproperlyConfigured, simple.dependency_ordered, raw, dependencies=dependencies)