class InMemoryUndoStackTests(TestCase):
"""
Tests for the in memory undo stack.
"""
def setUp(self):
"""
Configure an empty stack.
"""
def termination():
return lambda: True
def run_immediately(f):
f()
self.cooperator = Cooperator(
terminationPredicateFactory=termination,
scheduler=run_immediately)
self.undo = InMemoryUndoStack(self.cooperator.coiterate)
def test_provides_IUndoStack(self):
"""
InMemoryUndoStack provides IUndoStack.
"""
verifyObject(IUndoStack, self.undo)
def test_push(self):
"""
push puts an operation and it's arguments onto the stack.
"""
calls = []
def op(*args, **kwargs):
calls.append((args, kwargs))
self.undo.push(op, 'foo', bar='baz')
self.undo.rewind()
self.assertEqual(calls, [(('foo',), {'bar': 'baz'})])
def test_rewind_in_reverse_order(self):
"""
rewind invokes operations in the reverse of the order they are
pushed onto the stack. (Because it is a stack.)
"""
calls = []
def op(*args, **kwargs):
calls.append((args, kwargs))
self.undo.push(op, 'foo')
self.undo.push(op, 'bar')
self.undo.push(op, 'baz')
self.undo.rewind()
self.assertEqual(calls, [(('baz',), {}),
(('bar',), {}),
(('foo',), {})])
def test_rewind_handles_deferreds(self):
"""
rewind will wait on any deferreds returned by the undo operation
function.
"""
def op(op_d):
return op_d
op_d = Deferred()
self.undo.push(op, op_d)
d = self.undo.rewind()
self.assertNoResult(d)
op_d.callback(None)
self.successResultOf(d)
def test_rewind_blocks_on_deferreds_returned_by_ops(self):
"""
rewind will serialize operations waiting on any deferreds returned
before running the next operation.
"""
called = [0]
def op(op_d):
called[0] += 1
return op_d
op_d1 = Deferred()
self.undo.push(op, op_d1)
op_d2 = Deferred()
self.undo.push(op, op_d2)
d = self.undo.rewind()
self.assertEqual(called[0], 1)
self.assertNoResult(d)
op_d2.callback(None)
self.assertEqual(called[0], 2)
self.assertNoResult(d)
op_d1.callback(None)
self.successResultOf(d)
def test_rewind_stops_on_error(self):
"""
rewind errbacks it's completion deferred when it encounters an
error.
"""
called = [0]
def op(op_d):
called[0] += 1
return op_d
self.undo.push(op, None)
op_d1 = Deferred()
self.undo.push(op, op_d1)
d = self.undo.rewind()
self.assertNoResult(d)
class DummyOpFailure(Exception):
pass
op_d1.errback(DummyOpFailure())
self.assertEqual(called[0], 1)
self.failureResultOf(d, DummyOpFailure)
def test_rewind_empty_stack(self):
"""
rewind completes successfully if the stack is empty.
"""
self.successResultOf(self.undo.rewind())
class InMemoryUndoStackTests(SynchronousTestCase):
"""
Tests for the in memory undo stack.
"""
def setUp(self):
"""
Configure an empty stack.
"""
def termination():
return lambda: True
def run_immediately(f):
f()
self.cooperator = Cooperator(terminationPredicateFactory=termination,
scheduler=run_immediately)
self.undo = InMemoryUndoStack(self.cooperator.coiterate)
def test_provides_IUndoStack(self):
"""
InMemoryUndoStack provides IUndoStack.
"""
verifyObject(IUndoStack, self.undo)
def test_push(self):
"""
push puts an operation and it's arguments onto the stack.
"""
calls = []
def op(*args, **kwargs):
calls.append((args, kwargs))
self.undo.push(op, 'foo', bar='baz')
self.undo.rewind()
self.assertEqual(calls, [(('foo', ), {'bar': 'baz'})])
def test_rewind_in_reverse_order(self):
"""
rewind invokes operations in the reverse of the order they are
pushed onto the stack. (Because it is a stack.)
"""
calls = []
def op(*args, **kwargs):
calls.append((args, kwargs))
self.undo.push(op, 'foo')
self.undo.push(op, 'bar')
self.undo.push(op, 'baz')
self.undo.rewind()
self.assertEqual(calls, [(('baz', ), {}), (('bar', ), {}),
(('foo', ), {})])
def test_rewind_handles_deferreds(self):
"""
rewind will wait on any deferreds returned by the undo operation
function.
"""
def op(op_d):
return op_d
op_d = Deferred()
self.undo.push(op, op_d)
d = self.undo.rewind()
self.assertNoResult(d)
op_d.callback(None)
self.successResultOf(d)
def test_rewind_blocks_on_deferreds_returned_by_ops(self):
"""
rewind will serialize operations waiting on any deferreds returned
before running the next operation.
"""
called = [0]
def op(op_d):
called[0] += 1
return op_d
op_d1 = Deferred()
self.undo.push(op, op_d1)
op_d2 = Deferred()
self.undo.push(op, op_d2)
d = self.undo.rewind()
self.assertEqual(called[0], 1)
self.assertNoResult(d)
op_d2.callback(None)
self.assertEqual(called[0], 2)
self.assertNoResult(d)
op_d1.callback(None)
self.successResultOf(d)
def test_rewind_stops_on_error(self):
"""
rewind errbacks it's completion deferred when it encounters an
error.
"""
called = [0]
def op(op_d):
called[0] += 1
return op_d
self.undo.push(op, None)
op_d1 = Deferred()
self.undo.push(op, op_d1)
d = self.undo.rewind()
self.assertNoResult(d)
class DummyOpFailure(Exception):
pass
op_d1.errback(DummyOpFailure())
self.assertEqual(called[0], 1)
self.failureResultOf(d, DummyOpFailure)
def test_rewind_empty_stack(self):
"""
rewind completes successfully if the stack is empty.
"""
self.successResultOf(self.undo.rewind())
