django/tests/transactions/tests.py

from __future__ import unicode_literals

import sys
from unittest import skipIf, skipUnless

from django.db import connection, transaction, DatabaseError, IntegrityError
from django.test import TransactionTestCase, skipUnlessDBFeature
from django.test.utils import IgnoreDeprecationWarningsMixin
from django.utils import six

from .models import Reporter


@skipUnless(connection.features.uses_savepoints,
        "'atomic' requires transactions and savepoints.")
class AtomicTests(TransactionTestCase):
    """
    Tests for the atomic decorator and context manager.

    The tests make assertions on internal attributes because there isn't a
    robust way to ask the database for its current transaction state.

    Since the decorator syntax is converted into a context manager (see the
    implementation), there are only a few basic tests with the decorator
    syntax and the bulk of the tests use the context manager syntax.
    """

    available_apps = ['transactions']

    def test_decorator_syntax_commit(self):
        @transaction.atomic
        def make_reporter():
            Reporter.objects.create(first_name="Tintin")
        make_reporter()
        self.assertQuerysetEqual(Reporter.objects.all(), ['<Reporter: Tintin>'])

    def test_decorator_syntax_rollback(self):
        @transaction.atomic
        def make_reporter():
            Reporter.objects.create(first_name="Haddock")
            raise Exception("Oops, that's his last name")
        with six.assertRaisesRegex(self, Exception, "Oops"):
            make_reporter()
        self.assertQuerysetEqual(Reporter.objects.all(), [])

    def test_alternate_decorator_syntax_commit(self):
        @transaction.atomic()
        def make_reporter():
            Reporter.objects.create(first_name="Tintin")
        make_reporter()
        self.assertQuerysetEqual(Reporter.objects.all(), ['<Reporter: Tintin>'])

    def test_alternate_decorator_syntax_rollback(self):
        @transaction.atomic()
        def make_reporter():
            Reporter.objects.create(first_name="Haddock")
            raise Exception("Oops, that's his last name")
        with six.assertRaisesRegex(self, Exception, "Oops"):
            make_reporter()
        self.assertQuerysetEqual(Reporter.objects.all(), [])

    def test_commit(self):
        with transaction.atomic():
            Reporter.objects.create(first_name="Tintin")
        self.assertQuerysetEqual(Reporter.objects.all(), ['<Reporter: Tintin>'])

    def test_rollback(self):
        with six.assertRaisesRegex(self, Exception, "Oops"), transaction.atomic():
            Reporter.objects.create(first_name="Haddock")
            raise Exception("Oops, that's his last name")
        self.assertQuerysetEqual(Reporter.objects.all(), [])

    def test_nested_commit_commit(self):
        with transaction.atomic():
            Reporter.objects.create(first_name="Tintin")
            with transaction.atomic():
                Reporter.objects.create(first_name="Archibald", last_name="Haddock")
        self.assertQuerysetEqual(Reporter.objects.all(),
                ['<Reporter: Archibald Haddock>', '<Reporter: Tintin>'])

    def test_nested_commit_rollback(self):
        with transaction.atomic():
            Reporter.objects.create(first_name="Tintin")
            with six.assertRaisesRegex(self, Exception, "Oops"), transaction.atomic():
                Reporter.objects.create(first_name="Haddock")
                raise Exception("Oops, that's his last name")
        self.assertQuerysetEqual(Reporter.objects.all(), ['<Reporter: Tintin>'])

    def test_nested_rollback_commit(self):
        with six.assertRaisesRegex(self, Exception, "Oops"), transaction.atomic():
            Reporter.objects.create(last_name="Tintin")
            with transaction.atomic():
                Reporter.objects.create(last_name="Haddock")
            raise Exception("Oops, that's his first name")
        self.assertQuerysetEqual(Reporter.objects.all(), [])

    def test_nested_rollback_rollback(self):
        with six.assertRaisesRegex(self, Exception, "Oops"), transaction.atomic():
            Reporter.objects.create(last_name="Tintin")
            with six.assertRaisesRegex(self, Exception, "Oops"):
                with transaction.atomic():
                    Reporter.objects.create(first_name="Haddock")
                raise Exception("Oops, that's his last name")
            raise Exception("Oops, that's his first name")
        self.assertQuerysetEqual(Reporter.objects.all(), [])

    def test_merged_commit_commit(self):
        with transaction.atomic():
            Reporter.objects.create(first_name="Tintin")
            with transaction.atomic(savepoint=False):
                Reporter.objects.create(first_name="Archibald", last_name="Haddock")
        self.assertQuerysetEqual(Reporter.objects.all(),
                ['<Reporter: Archibald Haddock>', '<Reporter: Tintin>'])

    def test_merged_commit_rollback(self):
        with transaction.atomic():
            Reporter.objects.create(first_name="Tintin")
            with six.assertRaisesRegex(self, Exception, "Oops"), \
                    transaction.atomic(savepoint=False):
                Reporter.objects.create(first_name="Haddock")
                raise Exception("Oops, that's his last name")
        # Writes in the outer block are rolled back too.
        self.assertQuerysetEqual(Reporter.objects.all(), [])

    def test_merged_rollback_commit(self):
        with six.assertRaisesRegex(self, Exception, "Oops"), transaction.atomic():
            Reporter.objects.create(last_name="Tintin")
            with transaction.atomic(savepoint=False):
                Reporter.objects.create(last_name="Haddock")
            raise Exception("Oops, that's his first name")
        self.assertQuerysetEqual(Reporter.objects.all(), [])

    def test_merged_rollback_rollback(self):
        with six.assertRaisesRegex(self, Exception, "Oops"), transaction.atomic():
            Reporter.objects.create(last_name="Tintin")
            with six.assertRaisesRegex(self, Exception, "Oops"):
                with transaction.atomic(savepoint=False):
                    Reporter.objects.create(first_name="Haddock")
                raise Exception("Oops, that's his last name")
            raise Exception("Oops, that's his first name")
        self.assertQuerysetEqual(Reporter.objects.all(), [])

    def test_reuse_commit_commit(self):
        atomic = transaction.atomic()
        with atomic:
            Reporter.objects.create(first_name="Tintin")
            with atomic:
                Reporter.objects.create(first_name="Archibald", last_name="Haddock")
        self.assertQuerysetEqual(Reporter.objects.all(),
                ['<Reporter: Archibald Haddock>', '<Reporter: Tintin>'])

    def test_reuse_commit_rollback(self):
        atomic = transaction.atomic()
        with atomic:
            Reporter.objects.create(first_name="Tintin")
            with six.assertRaisesRegex(self, Exception, "Oops"), atomic:
                Reporter.objects.create(first_name="Haddock")
                raise Exception("Oops, that's his last name")
        self.assertQuerysetEqual(Reporter.objects.all(), ['<Reporter: Tintin>'])

    def test_reuse_rollback_commit(self):
        atomic = transaction.atomic()
        with six.assertRaisesRegex(self, Exception, "Oops"), atomic:
            Reporter.objects.create(last_name="Tintin")
            with atomic:
                Reporter.objects.create(last_name="Haddock")
            raise Exception("Oops, that's his first name")
        self.assertQuerysetEqual(Reporter.objects.all(), [])

    def test_reuse_rollback_rollback(self):
        atomic = transaction.atomic()
        with six.assertRaisesRegex(self, Exception, "Oops"), atomic:
            Reporter.objects.create(last_name="Tintin")
            with six.assertRaisesRegex(self, Exception, "Oops"):
                with atomic:
                    Reporter.objects.create(first_name="Haddock")
                raise Exception("Oops, that's his last name")
            raise Exception("Oops, that's his first name")
        self.assertQuerysetEqual(Reporter.objects.all(), [])

    def test_force_rollback(self):
        with transaction.atomic():
            Reporter.objects.create(first_name="Tintin")
            # atomic block shouldn't rollback, but force it.
            self.assertFalse(transaction.get_rollback())
            transaction.set_rollback(True)
        self.assertQuerysetEqual(Reporter.objects.all(), [])

    def test_prevent_rollback(self):
        with transaction.atomic():
            Reporter.objects.create(first_name="Tintin")
            sid = transaction.savepoint()
            # trigger a database error inside an inner atomic without savepoint
            with self.assertRaises(DatabaseError), transaction.atomic(savepoint=False):
                connection.cursor().execute(
                        "SELECT no_such_col FROM transactions_reporter")
            transaction.savepoint_rollback(sid)
            # atomic block should rollback, but prevent it, as we just did it.
            self.assertTrue(transaction.get_rollback())
            transaction.set_rollback(False)
        self.assertQuerysetEqual(Reporter.objects.all(), ['<Reporter: Tintin>'])


class AtomicInsideTransactionTests(AtomicTests):
    """All basic tests for atomic should also pass within an existing transaction."""

    def setUp(self):
        self.atomic = transaction.atomic()
        self.atomic.__enter__()

    def tearDown(self):
        self.atomic.__exit__(*sys.exc_info())


@skipIf(connection.features.autocommits_when_autocommit_is_off,
        "This test requires a non-autocommit mode that doesn't autocommit.")
class AtomicWithoutAutocommitTests(AtomicTests):
    """All basic tests for atomic should also pass when autocommit is turned off."""

    def setUp(self):
        transaction.set_autocommit(False)

    def tearDown(self):
        # The tests access the database after exercising 'atomic', initiating
        # a transaction ; a rollback is required before restoring autocommit.
        transaction.rollback()
        transaction.set_autocommit(True)


@skipIf(connection.features.autocommits_when_autocommit_is_off,
        "This test requires a non-autocommit mode that doesn't autocommit.")
class AtomicInsideLegacyTransactionManagementTests(AtomicTests):

    def setUp(self):
        transaction.enter_transaction_management()

    def tearDown(self):
        # The tests access the database after exercising 'atomic', making the
        # connection dirty; a rollback is required to make it clean.
        transaction.rollback()
        transaction.leave_transaction_management()


@skipUnless(connection.features.uses_savepoints,
        "'atomic' requires transactions and savepoints.")
class AtomicMergeTests(TransactionTestCase):
    """Test merging transactions with savepoint=False."""

    available_apps = ['transactions']

    def test_merged_outer_rollback(self):
        with transaction.atomic():
            Reporter.objects.create(first_name="Tintin")
            with transaction.atomic(savepoint=False):
                Reporter.objects.create(first_name="Archibald", last_name="Haddock")
                with six.assertRaisesRegex(self, Exception, "Oops"), \
                        transaction.atomic(savepoint=False):
                    Reporter.objects.create(first_name="Tournesol")
                    raise Exception("Oops, that's his last name")
                # It wasn't possible to roll back
                self.assertEqual(Reporter.objects.count(), 3)
            # It wasn't possible to roll back
            self.assertEqual(Reporter.objects.count(), 3)
        # The outer block must roll back
        self.assertQuerysetEqual(Reporter.objects.all(), [])

    def test_merged_inner_savepoint_rollback(self):
        with transaction.atomic():
            Reporter.objects.create(first_name="Tintin")
            with transaction.atomic():
                Reporter.objects.create(first_name="Archibald", last_name="Haddock")
                with six.assertRaisesRegex(self, Exception, "Oops"), \
                        transaction.atomic(savepoint=False):
                    Reporter.objects.create(first_name="Tournesol")
                    raise Exception("Oops, that's his last name")
                # It wasn't possible to roll back
                self.assertEqual(Reporter.objects.count(), 3)
            # The first block with a savepoint must roll back
            self.assertEqual(Reporter.objects.count(), 1)
        self.assertQuerysetEqual(Reporter.objects.all(), ['<Reporter: Tintin>'])

    def test_merged_outer_rollback_after_inner_failure_and_inner_success(self):
        with transaction.atomic():
            Reporter.objects.create(first_name="Tintin")
            # Inner block without a savepoint fails
            with six.assertRaisesRegex(self, Exception, "Oops"), \
                    transaction.atomic(savepoint=False):
                Reporter.objects.create(first_name="Haddock")
                raise Exception("Oops, that's his last name")
            # It wasn't possible to roll back
            self.assertEqual(Reporter.objects.count(), 2)
            # Inner block with a savepoint succeeds
            with transaction.atomic(savepoint=False):
                Reporter.objects.create(first_name="Archibald", last_name="Haddock")
            # It still wasn't possible to roll back
            self.assertEqual(Reporter.objects.count(), 3)
        # The outer block must rollback
        self.assertQuerysetEqual(Reporter.objects.all(), [])


@skipUnless(connection.features.uses_savepoints,
        "'atomic' requires transactions and savepoints.")
class AtomicErrorsTests(TransactionTestCase):

    available_apps = []

    def test_atomic_prevents_setting_autocommit(self):
        autocommit = transaction.get_autocommit()
        with transaction.atomic(), \
                self.assertRaises(transaction.TransactionManagementError):
            transaction.set_autocommit(not autocommit)
        # Make sure autocommit wasn't changed.
        self.assertEqual(connection.autocommit, autocommit)

    def test_atomic_prevents_calling_transaction_methods(self):
        with transaction.atomic():
            with self.assertRaises(transaction.TransactionManagementError):
                transaction.commit()
            with self.assertRaises(transaction.TransactionManagementError):
                transaction.rollback()

    def test_atomic_prevents_calling_transaction_management_methods(self):
        with transaction.atomic():
            with self.assertRaises(transaction.TransactionManagementError):
                transaction.enter_transaction_management()
            with self.assertRaises(transaction.TransactionManagementError):
                transaction.leave_transaction_management()


class AtomicMiscTests(TransactionTestCase):

    available_apps = []

    def test_wrap_callable_instance(self):
        # Regression test for #20028
        class Callable(object):
            def __call__(self):
                pass
        # Must not raise an exception
        transaction.atomic(Callable())


class TransactionTests(IgnoreDeprecationWarningsMixin, TransactionTestCase):

    available_apps = ['transactions']

    def create_a_reporter_then_fail(self, first, last):
        a = Reporter(first_name=first, last_name=last)
        a.save()
        raise Exception("I meant to do that")

    def remove_a_reporter(self, first_name):
        r = Reporter.objects.get(first_name="Alice")
        r.delete()

    def manually_managed(self):
        r = Reporter(first_name="Dirk", last_name="Gently")
        r.save()
        transaction.commit()

    def manually_managed_mistake(self):
        r = Reporter(first_name="Edward", last_name="Woodward")
        r.save()
        # Oops, I forgot to commit/rollback!

    @skipUnlessDBFeature('supports_transactions')
    def test_autocommit(self):
        """
        The default behavior is to autocommit after each save() action.
        """
        self.assertRaises(Exception,
            self.create_a_reporter_then_fail,
            "Alice", "Smith"
        )

        # The object created before the exception still exists
        self.assertEqual(Reporter.objects.count(), 1)

    @skipUnlessDBFeature('supports_transactions')
    def test_autocommit_decorator(self):
        """
        The autocommit decorator works exactly the same as the default behavior.
        """
        autocomitted_create_then_fail = transaction.autocommit(
            self.create_a_reporter_then_fail
        )
        self.assertRaises(Exception,
            autocomitted_create_then_fail,
            "Alice", "Smith"
        )
        # Again, the object created before the exception still exists
        self.assertEqual(Reporter.objects.count(), 1)

    @skipUnlessDBFeature('supports_transactions')
    def test_autocommit_decorator_with_using(self):
        """
        The autocommit decorator also works with a using argument.
        """
        autocomitted_create_then_fail = transaction.autocommit(using='default')(
            self.create_a_reporter_then_fail
        )
        self.assertRaises(Exception,
            autocomitted_create_then_fail,
            "Alice", "Smith"
        )
        # Again, the object created before the exception still exists
        self.assertEqual(Reporter.objects.count(), 1)

    @skipUnlessDBFeature('supports_transactions')
    def test_commit_on_success(self):
        """
        With the commit_on_success decorator, the transaction is only committed
        if the function doesn't throw an exception.
        """
        committed_on_success = transaction.commit_on_success(
            self.create_a_reporter_then_fail)
        self.assertRaises(Exception, committed_on_success, "Dirk", "Gently")
        # This time the object never got saved
        self.assertEqual(Reporter.objects.count(), 0)

    @skipUnlessDBFeature('supports_transactions')
    def test_commit_on_success_with_using(self):
        """
        The commit_on_success decorator also works with a using argument.
        """
        using_committed_on_success = transaction.commit_on_success(using='default')(
            self.create_a_reporter_then_fail
        )
        self.assertRaises(Exception,
            using_committed_on_success,
            "Dirk", "Gently"
        )
        # This time the object never got saved
        self.assertEqual(Reporter.objects.count(), 0)

    @skipUnlessDBFeature('supports_transactions')
    def test_commit_on_success_succeed(self):
        """
        If there aren't any exceptions, the data will get saved.
        """
        Reporter.objects.create(first_name="Alice", last_name="Smith")
        remove_comitted_on_success = transaction.commit_on_success(
            self.remove_a_reporter
        )
        remove_comitted_on_success("Alice")
        self.assertEqual(list(Reporter.objects.all()), [])

    @skipUnlessDBFeature('supports_transactions')
    def test_commit_on_success_exit(self):
        @transaction.autocommit()
        def gen_reporter():
            @transaction.commit_on_success
            def create_reporter():
                Reporter.objects.create(first_name="Bobby", last_name="Tables")

            create_reporter()
            # Much more formal
            r = Reporter.objects.get()
            r.first_name = "Robert"
            r.save()

        gen_reporter()
        r = Reporter.objects.get()
        self.assertEqual(r.first_name, "Robert")


    @skipUnlessDBFeature('supports_transactions')
    def test_manually_managed(self):
        """
        You can manually manage transactions if you really want to, but you
        have to remember to commit/rollback.
        """
        manually_managed = transaction.commit_manually(self.manually_managed)
        manually_managed()
        self.assertEqual(Reporter.objects.count(), 1)

    @skipUnlessDBFeature('supports_transactions')
    def test_manually_managed_mistake(self):
        """
        If you forget, you'll get bad errors.
        """
        manually_managed_mistake = transaction.commit_manually(
            self.manually_managed_mistake
        )
        self.assertRaises(transaction.TransactionManagementError,
            manually_managed_mistake)

    @skipUnlessDBFeature('supports_transactions')
    def test_manually_managed_with_using(self):
        """
        The commit_manually function also works with a using argument.
        """
        using_manually_managed_mistake = transaction.commit_manually(using='default')(
            self.manually_managed_mistake
        )
        self.assertRaises(transaction.TransactionManagementError,
            using_manually_managed_mistake
        )


class TransactionRollbackTests(IgnoreDeprecationWarningsMixin, TransactionTestCase):

    available_apps = ['transactions']

    def execute_bad_sql(self):
        cursor = connection.cursor()
        cursor.execute("INSERT INTO transactions_reporter (first_name, last_name) VALUES ('Douglas', 'Adams');")

    @skipUnlessDBFeature('requires_rollback_on_dirty_transaction')
    def test_bad_sql(self):
        """
        Regression for #11900: If a function wrapped by commit_on_success
        writes a transaction that can't be committed, that transaction should
        be rolled back. The bug is only visible using the psycopg2 backend,
        though the fix is generally a good idea.
        """
        execute_bad_sql = transaction.commit_on_success(self.execute_bad_sql)
        self.assertRaises(IntegrityError, execute_bad_sql)
        transaction.rollback()

class TransactionContextManagerTests(IgnoreDeprecationWarningsMixin, TransactionTestCase):

    available_apps = ['transactions']

    def create_reporter_and_fail(self):
        Reporter.objects.create(first_name="Bob", last_name="Holtzman")
        raise Exception

    @skipUnlessDBFeature('supports_transactions')
    def test_autocommit(self):
        """
        The default behavior is to autocommit after each save() action.
        """
        with self.assertRaises(Exception):
            self.create_reporter_and_fail()
        # The object created before the exception still exists
        self.assertEqual(Reporter.objects.count(), 1)

    @skipUnlessDBFeature('supports_transactions')
    def test_autocommit_context_manager(self):
        """
        The autocommit context manager works exactly the same as the default
        behavior.
        """
        with self.assertRaises(Exception), transaction.autocommit():
            self.create_reporter_and_fail()

        self.assertEqual(Reporter.objects.count(), 1)

    @skipUnlessDBFeature('supports_transactions')
    def test_autocommit_context_manager_with_using(self):
        """
        The autocommit context manager also works with a using argument.
        """
        with self.assertRaises(Exception), transaction.autocommit(using="default"):
            self.create_reporter_and_fail()

        self.assertEqual(Reporter.objects.count(), 1)

    @skipUnlessDBFeature('supports_transactions')
    def test_commit_on_success(self):
        """
        With the commit_on_success context manager, the transaction is only
        committed if the block doesn't throw an exception.
        """
        with self.assertRaises(Exception), transaction.commit_on_success():
            self.create_reporter_and_fail()

        self.assertEqual(Reporter.objects.count(), 0)

    @skipUnlessDBFeature('supports_transactions')
    def test_commit_on_success_with_using(self):
        """
        The commit_on_success context manager also works with a using argument.
        """
        with self.assertRaises(Exception), transaction.commit_on_success(using="default"):
            self.create_reporter_and_fail()

        self.assertEqual(Reporter.objects.count(), 0)

    @skipUnlessDBFeature('supports_transactions')
    def test_commit_on_success_succeed(self):
        """
        If there aren't any exceptions, the data will get saved.
        """
        Reporter.objects.create(first_name="Alice", last_name="Smith")
        with transaction.commit_on_success():
            Reporter.objects.filter(first_name="Alice").delete()

        self.assertQuerysetEqual(Reporter.objects.all(), [])

    @skipUnlessDBFeature('supports_transactions')
    def test_commit_on_success_exit(self):
        with transaction.autocommit():
            with transaction.commit_on_success():
                Reporter.objects.create(first_name="Bobby", last_name="Tables")

            # Much more formal
            r = Reporter.objects.get()
            r.first_name = "Robert"
            r.save()

        r = Reporter.objects.get()
        self.assertEqual(r.first_name, "Robert")

    @skipUnlessDBFeature('supports_transactions')
    def test_manually_managed(self):
        """
        You can manually manage transactions if you really want to, but you
        have to remember to commit/rollback.
        """
        with transaction.commit_manually():
            Reporter.objects.create(first_name="Libby", last_name="Holtzman")
            transaction.commit()
        self.assertEqual(Reporter.objects.count(), 1)

    @skipUnlessDBFeature('supports_transactions')
    def test_manually_managed_mistake(self):
        """
        If you forget, you'll get bad errors.
        """
        with self.assertRaises(transaction.TransactionManagementError), \
                transaction.commit_manually():
            Reporter.objects.create(first_name="Scott", last_name="Browning")

    @skipUnlessDBFeature('supports_transactions')
    def test_manually_managed_with_using(self):
        """
        The commit_manually function also works with a using argument.
        """
        with self.assertRaises(transaction.TransactionManagementError), \
                transaction.commit_manually(using="default"):
            Reporter.objects.create(first_name="Walter", last_name="Cronkite")

    @skipUnlessDBFeature('requires_rollback_on_dirty_transaction')
    def test_bad_sql(self):
        """
        Regression for #11900: If a block wrapped by commit_on_success
        writes a transaction that can't be committed, that transaction should
        be rolled back. The bug is only visible using the psycopg2 backend,
        though the fix is generally a good idea.
        """
        with self.assertRaises(IntegrityError), transaction.commit_on_success():
            cursor = connection.cursor()
            cursor.execute("INSERT INTO transactions_reporter (first_name, last_name) VALUES ('Douglas', 'Adams');")
        transaction.rollback()