def enqueue_dequeue(q: Queue, howmany: int):
"""Enqueue and dequeue 'howmany' items to/from Queue 'q'.
"""
for i in range(howmany):
q.enqueue(42)
q.dequeue()
class TypicalTestCase(unittest.TestCase):
"""A comprehensive tester of typical behaviour of Queue.
"""
def setUp(self):
"""Set up an empty queue.
"""
self.queue = Queue()
def tearDown(self):
"""Clean up.
"""
self.queue = None
def testAll(self):
"""Check enqueueing and dequeueing several items.
"""
for item in range(20):
self.queue.enqueue(item)
self.assertFalse(
self.queue.is_empty(),
'Queue should not be empty after adding item ' + str(item))
item = 0
while not self.queue.is_empty():
front = self.queue.dequeue()
self.assertEqual(
front, item, 'Wrong item at the front of the Queue. Found ' +
str(front) + ' but expected ' + str(item))
item += 1
class MutableTestCase(unittest.TestCase):
"""Test adding a mutable object. Make sure the Queue adds the object,
and does not make a copy.
"""
def setUp(self):
"""Set up an empty queue.
"""
self.queue = Queue()
def tearDown(self):
"""Clean up.
"""
self.queue = None
def testMutable(self):
"""Test with a list.
"""
item = [1, 2, 3]
self.queue.enqueue(item)
item.append(42)
self.assertEqual(self.queue.front(), item,
'mutable item did not change!')
self.assertEqual(self.queue.dequeue(), item,
'mutable item did not change!')
class SingletonTestCase(unittest.TestCase):
"""Check whether enqueueing a single item makes it appear at the front.
"""
def setUp(self):
"""Set up a queue with a single element.
"""
self.queue = Queue()
self.queue.enqueue('a')
def tearDown(self):
"""Clean up.
"""
self.queue = None
def testIsEmpty(self):
"""Test is_empty() on non-empty Queue.
"""
self.assertFalse(self.queue.is_empty(),
'is_empty returned True on non-empty Queue!')
def testFront(self):
"""Test front() on a non-empty Queue.
"""
front = self.queue.front()
self.assertEqual(
front, 'a', 'The item at the front should have been "a" but was ' +
front + '.')
def testDequeue(self):
"""Test dequeue() on a non-empty Queue.
"""
front = self.queue.dequeue()
self.assertEqual(
front, 'a', 'The item at the front should have been "a" but was ' +
front + '.')
self.assertTrue(self.queue.is_empty(),
'Queue with one element not empty after dequeue().')