def test_inner_and_outer_changes_persisted_on_successful_exit(cxn, other_cxn):
with Transaction(cxn):
insert_row(cxn, 'outer-before')
with Transaction(cxn):
insert_row(cxn, 'inner')
insert_row(cxn, 'outer-after')
assert_rows(cxn, {'outer-before', 'inner', 'outer-after'})
assert_rows(other_cxn, {'outer-before', 'inner', 'outer-after'})
def test_inner_and_outer_changes_discarded_on_outer_exception(cxn, other_cxn):
with pytest.raises(ExpectedException):
with Transaction(cxn):
insert_row(cxn, 'outer')
with Transaction(cxn):
insert_row(cxn, 'inner')
raise ExpectedException()
assert_rows(cxn, set())
assert_rows(other_cxn, set())
def test_explicit_rollback_inner_discards_only_inner_changes(cxn, other_cxn):
with Transaction(cxn):
insert_row(cxn, 'outer-before')
with Transaction(cxn) as inner:
insert_row(cxn, 'inner')
inner.rollback()
insert_row(cxn, 'outer-after')
assert_rows(cxn, {'outer-before', 'outer-after'})
assert_rows(other_cxn, {'outer-before', 'outer-after'})
def test_explicit_rollback_outer_discards_inner_and_outer_changes(
cxn, other_cxn):
with Transaction(cxn) as outer:
insert_row(cxn, 'outer')
with Transaction(cxn):
insert_row(cxn, 'inner')
outer.rollback()
assert_rows(cxn, set())
assert_rows(other_cxn, set())
def test_explicit_rollback_of_outer_transaction_while_inner_transaction_is_active_not_allowed(
cxn):
with Transaction(cxn) as outer:
with Transaction(cxn):
with pytest.raises(Exception,
match=re.escape(
'Cannot rollback outer transaction from '
'nested transaction context.')):
outer.rollback()
def test_transactions_on_multiple_connections_are_independent(cxn, other_cxn):
with Transaction(cxn) as outer_txn:
insert_row(cxn, 'outer')
with Transaction(other_cxn):
insert_row(other_cxn, 'inner')
outer_txn.rollback()
assert_rows(other_cxn, {'inner'}, still_in_transaction=True)
assert_rows(cxn, {'inner'})
def test_inner_changes_discarded_on_exception_but_outer_changes_persisted_on_successful_exit(
cxn, other_cxn):
with Transaction(cxn):
insert_row(cxn, 'outer-before')
with pytest.raises(ExpectedException):
with Transaction(cxn):
insert_row(cxn, 'inner')
raise ExpectedException()
insert_row(cxn, 'outer-after')
assert_rows(cxn, {'outer-before', 'outer-after'})
assert_rows(other_cxn, {'outer-before', 'outer-after'})
def test_no_open_transaction_on_exception(cxn):
assert_not_in_transaction(cxn)
with pytest.raises(ExpectedException):
with Transaction(cxn):
assert_in_transaction(cxn)
raise ExpectedException('This rolls back the transaction')
assert_not_in_transaction(cxn)
def test_manual_transaction_management_inside_context_explicit_commit(
cxn, other_cxn):
def classic_method(cxn):
assert cxn.autocommit is False
insert_row(cxn, 'inner')
cxn.commit()
txn = Transaction(cxn).__enter__()
insert_row(cxn, 'outer')
classic_method(cxn)
# All changes are committed and visible immediately :-(
assert_rows(other_cxn, {'inner', 'outer'})
# Context exit fails :-((
with pytest.raises(psycopg2.InternalError, match='no such savepoint'):
txn.__exit__(None, None, None)
def test_autocommit_off_successful_exit(cxn):
cxn.autocommit = False
assert_not_in_transaction(cxn)
with Transaction(cxn):
assert_in_transaction(cxn)
assert_not_in_transaction(cxn)
assert cxn.autocommit is False
def test_autocommit_on_successful_exit(cxn):
assert cxn.autocommit is True, 'Pre-condition'
assert_not_in_transaction(cxn)
with Transaction(cxn):
assert_in_transaction(cxn)
assert_not_in_transaction(cxn)
assert cxn.autocommit is True
def test_transaction_stack_dict_does_not_leak(cxn):
assert len(
Transaction._Transaction__transaction_stack) == 0, 'Pre-condition'
with Transaction(cxn):
assert len(Transaction._Transaction__transaction_stack) == 1
assert len(
Transaction._Transaction__transaction_stack) == 0, 'Post-condition'
def test_changes_discarded_on_exception(cxn, other_cxn):
with pytest.raises(ExpectedException):
with Transaction(cxn):
insert_row(cxn, 'value')
raise ExpectedException('This discards the insert')
assert_rows(cxn, set())
assert_rows(other_cxn, set())
def test_manual_transaction_management_with_connection_subclass_commit_rollback_raises(
python_cxn, other_cxn):
def classic_method(python_cxn, commit):
if commit:
python_cxn.commit()
else:
python_cxn.rollback()
with Transaction(python_cxn):
with pytest.raises(
Exception,
match=re.escape(
'Explicit commit() forbidden within a Transaction '
'context. (Transaction will be automatically committed '
'on successful exit from context.)')):
classic_method(python_cxn, commit=True)
with pytest.raises(
Exception,
match=re.escape(
'Explicit rollback() forbidden within a Transaction '
'context. (Either call Transaction.rollback() or allow '
'an exception to propogate out of the context.)')):
classic_method(python_cxn, commit=False)
assert_rows(python_cxn, set())
assert_rows(other_cxn, set())
def test_forced_discard_changes_discarded_on_exception(cxn, other_cxn):
with pytest.raises(ExpectedException):
with Transaction(cxn, force_discard=True):
insert_row(cxn, 'value')
raise ExpectedException()
assert_rows(cxn, set())
assert_rows(other_cxn, set())
def test_forced_discard_explicit_rollback_followed_by_successful_exit(
cxn, other_cxn):
with Transaction(cxn, force_discard=True) as txn:
insert_row(cxn, 'value')
txn.rollback()
assert_rows(cxn, set())
assert_rows(other_cxn, set())
def test_explicit_rollback_repeated_raises(cxn):
with Transaction(cxn) as txn:
insert_row(cxn, 'value')
txn.rollback()
with pytest.raises(
Exception,
match=re.escape('Transaction already rolled back.')):
txn.rollback()
def test_explicit_rollback_followed_by_exception_inside_context(
cxn, other_cxn):
with pytest.raises(ExpectedException):
with Transaction(cxn) as txn:
insert_row(cxn, 'value')
txn.rollback()
raise ExpectedException()
assert_rows(cxn, set())
assert_rows(other_cxn, set())
def test_autocommit_off_exception(cxn):
cxn.autocommit = False
assert_not_in_transaction(cxn)
with pytest.raises(ExpectedException):
with Transaction(cxn):
assert_in_transaction(cxn)
raise ExpectedException('This rolls back the transaction')
assert_not_in_transaction(cxn)
assert cxn.autocommit is False
def test_context_manager_is_reusable(cxn):
txn = Transaction(cxn)
assert_not_in_transaction(cxn)
with txn:
assert_in_transaction(cxn)
assert_not_in_transaction(cxn)
with txn:
assert_in_transaction(cxn)
assert_not_in_transaction(cxn)
def test_autocommit_on_exception(cxn):
assert cxn.autocommit is True, 'Pre-condition'
assert_not_in_transaction(cxn)
with pytest.raises(ExpectedException):
with Transaction(cxn):
assert_in_transaction(cxn)
raise ExpectedException('This rolls back the transaction')
assert_not_in_transaction(cxn)
assert cxn.autocommit is True
def check(cxn):
original_commit, original_rollback = cxn.commit, cxn.rollback
original_dict_keys = set(cxn.__dict__.keys())
with Transaction(cxn):
pass
assert (original_commit, original_rollback) == (cxn.commit,
cxn.rollback)
assert original_dict_keys == set(
cxn.__dict__.keys()), 'Instance dict has changed'
def test_autocommit_off_but_no_transaction_started_successful_exit_commits_changes(
cxn, other_cxn):
cxn.autocommit = False
assert_not_in_transaction(cxn)
with Transaction(cxn):
insert_row(cxn, 'new')
assert_not_in_transaction(cxn)
assert cxn.autocommit is False
assert_rows(cxn, {'new'})
assert_rows(other_cxn, {'new'}) # Changes committed.
def test_manual_transaction_management_inside_context_explicit_rollback(
cxn, other_cxn):
def classic_method(cxn):
assert cxn.autocommit is False
insert_row(cxn, 'inner')
cxn.rollback()
txn = Transaction(cxn).__enter__()
insert_row(cxn, 'outer')
assert_in_transaction(cxn)
classic_method(cxn)
assert_not_in_transaction(cxn)
# Context exit fails :-(
with pytest.raises(psycopg2.InternalError, match='no such savepoint'):
txn.__exit__(None, None, None)
# All changes are discarded :-((
assert_rows(other_cxn, set())
def test_context_manager_is_not_reentrant(cxn):
# As the context manager stores state on self, calling __enter__() a second time overwrites it
txn = Transaction(cxn)
assert_not_in_transaction(cxn)
with txn:
assert_in_transaction(cxn)
with txn: # Don't do this!
assert_in_transaction(cxn)
assert_in_transaction(cxn)
assert_not_in_transaction(cxn)
def test_manual_transaction_management_inside_context_implicit_rollback(
cxn, other_cxn):
def method(cxn):
# This method implicitly rolls back the current transaction :-(
# See: https://github.com/psycopg/psycopg2/issues/950
cxn.set_client_encoding('LATIN1')
txn = Transaction(cxn).__enter__()
insert_row(cxn, 'outer')
assert_in_transaction(cxn)
method(cxn)
assert_not_in_transaction(cxn)
# Context exit fails :-(
with pytest.raises(psycopg2.InternalError, match='no such savepoint'):
txn.__exit__(None, None, None)
# All changes are discarded :-((
assert_rows(other_cxn, set())
def test_manual_enter_and_exit_out_of_order_exit_raises_assertion(cxn):
t1, t2 = Transaction(cxn), Transaction(cxn)
t1.__enter__()
t2.__enter__()
with pytest.raises(
AssertionError,
match=re.escape(
'Out-of-order Transaction context exits. Are you calling '
'__exit__() manually and getting it wrong?')):
t1.__exit__(None, None, None)
def test_autocommit_off_transaction_in_progress_successful_exit_leaves_transaction_running(
cxn, other_cxn):
cxn.autocommit = False
insert_row(cxn, 'prior')
assert_in_transaction(cxn)
with Transaction(cxn):
insert_row(cxn, 'new')
assert_in_transaction(cxn)
assert cxn.autocommit is False
assert_rows(cxn, {'prior', 'new'}, still_in_transaction=True)
assert_rows(
other_cxn,
set()) # Nothing committed; changes not visible on another connection
def test_autocommit_off_but_no_transaction_started_exception_discards_changes(
cxn, other_cxn):
cxn.autocommit = False
assert_not_in_transaction(cxn)
with pytest.raises(ExpectedException):
with Transaction(cxn):
insert_row(cxn, 'new')
raise ExpectedException(
'This rolls back just the inner transaction')
assert_not_in_transaction(cxn)
assert cxn.autocommit is False
assert_rows(cxn, set())
assert_rows(other_cxn, set()) # No changes committed.
def test_manual_transaction_management_inside_context_autocommit_raises(
cxn, python_cxn):
def classic_method(cxn, autocommit):
cxn.autocommit = autocommit # Setting autocommit always raises
insert_row(cxn, 'inner')
cxn.commit()
for i, cxn in enumerate((cxn, python_cxn)):
for autocommit in (True, False):
with Transaction(cxn):
with pytest.raises(
psycopg2.ProgrammingError,
match='set_session cannot be used inside a transaction'
):
classic_method(cxn, autocommit)