class HashMapTests(unittest.TestCase, DictTestCases):
def setUp(self):
self.uut = HashMap()
def mock_hashes_to(self, index=0):
class Mock(object):
def __hash__(self):
return index
def __str__(self):
return "mock(%s)" % index
__repr__ = __str__
return Mock()
def test_initial_current_capacity_is_16(self):
self.assertEqual(16, self.uut.capacity())
def test_initial_doubling_size_is_12(self):
self.assertEqual(12, self.uut.doubling_size())
def test_when_inialized_with_one_half_then_doubling_size_is_8(self):
uut = HashMap(0.5)
self.assertEqual(8, uut.doubling_size())
def test_initial_len_is_0(self):
self.assertEqual(0, len(self.uut))
def test_insertion_increses_size_to_1(self):
self.uut.insert(self.mock_hashes_to(), 42)
def test_collisions_are_handled(self):
first = self.mock_hashes_to(1)
second = self.mock_hashes_to(1)
self.uut.insert(first, "spam")
self.uut.insert(second, "eggs")
self.assertEqual("spam", self.uut.get(first))
self.assertEqual("eggs", self.uut.get(second))
def test_inserting_items_with_a_higher_value_works(self):
item = self.mock_hashes_to(99)
self.uut.insert(item, 42)
self.assertEqual(42, self.uut.get(item))
def test_when_at_doubling_size_then_the_capacity_doubles(self):
for i in xrange(11):
self.uut.insert(i, "_")
self.assertEqual(16, self.uut.capacity())
self.uut.insert(12, "_")
self.assertEqual(32, self.uut.capacity())
self.assertEqual(12, len(self.uut))
def test_len_is_0_after_delete_of_empty(self):
self.uut.delete("foo")
self.assertEqual(0, len(self.uut))
def test_len_is_0_after_delete_of_only_item(self):
self.uut.insert("foo", "_")
self.uut.delete("foo")
self.assertEqual(0, len(self.uut))
def test_len_is_0_after_delete_of_only_item_twice(self):
self.uut.insert("foo", "_")
self.uut.delete("foo")
self.uut.delete("foo")
self.assertEqual(0, len(self.uut))
def test_when_inialized_with_one_half_then_doubling_size_is_8(self):
uut = HashMap(0.5)
self.assertEqual(8, uut.doubling_size())
