def test_string_representations(self):
chain = ChainSequence('hi', [2, 1, 3, 4, 7])
self.assertEqual(str(chain), "ChainSequence('hi', [2, 1, 3, 4, 7])")
self.assertEqual(repr(chain), "ChainSequence('hi', [2, 1, 3, 4, 7])")
self.assertEqual(str(ChainSequence()), "ChainSequence()")
self.assertEqual(
str(ChainSequence("I don't know\n")),
r"""ChainSequence("I don't know\n")""",
)
def test_indexable(self):
x = [1, 2, 3]
y = (4, 5, 6)
chain = ChainSequence(x, y)
self.assertEqual(chain[0], 1)
self.assertEqual(chain[3], 4)
self.assertEqual(chain[-1], 6)
self.assertEqual(chain[-4], 3)
self.assertEqual(chain[1], 2)
self.assertEqual(chain[4], 5)
def test_changing_wrapped_sequence_changes_chainsequence(self):
numbers = [1, 2, 3]
word = 'hello'
chain = ChainSequence(numbers, word)
self.assertEqual(len(chain), 8)
self.assertEqual(chain[4], 'e')
self.assertEqual(chain[3], 'h')
numbers.append(9)
self.assertEqual(len(chain), 9)
self.assertEqual(chain[4], 'h')
self.assertEqual(chain[3], 9)
def test_indexing_large_sequences_lazily(self):
x = range(1, 10000, 2)
y = range(50000, 0, -1)
z = range(10000000)
chain = ChainSequence(x, y, z)
self.assertEqual(chain[0], 1)
self.assertEqual(chain[3], 7)
self.assertEqual(chain[-1], 9999999)
self.assertEqual(chain[-4], 9999996)
self.assertEqual(chain[1], 3)
self.assertEqual(chain[4], 9)
def test_addition(self):
chain1 = ChainSequence([2, 1], [3])
chain2 = chain1 + [4, 7]
self.assertEqual(list(chain2), [2, 1, 3, 4, 7])
self.assertEqual(list(chain1), [2, 1, 3])
chain3 = chain1
self.assertIs(chain1, chain3)
chain1 += [0, 9]
self.assertIs(chain1, chain3)
self.assertEqual(list(chain1), [2, 1, 3, 0, 9])
self.assertEqual(list(chain2), [2, 1, 3, 4, 7])
self.assertEqual(list(chain3), [2, 1, 3, 0, 9])
def test_sliceability(self):
chain = ChainSequence('hi', [2, 1, 3, 4, 7])
view = chain[:4]
self.assertEqual(list(view), ['h', 'i', 2, 1])
chain.sequences[1] = 'ya!'
self.assertEqual(list(view), ['h', 'i', 'y', 'a'])
def test_sequences_attribute(self):
sequences = ['hello', range(5), [True, False]]
chain = ChainSequence(*sequences)
self.assertEqual(chain.sequences, sequences)
def test_empty_sequences(self):
chain = ChainSequence('hi', [], range(5), (), '')
self.assertEqual(len(chain), 7)
self.assertEqual(chain[1], 'i')
self.assertEqual(chain[2], 0)
self.assertEqual(chain[-1], 4)
def test_can_be_looped_over_multiple_times(self):
chain = ChainSequence([1, 2, 3], (4, 5, 6))
self.assertEqual(list(chain), [1, 2, 3, 4, 5, 6])
self.assertEqual(tuple(chain), (1, 2, 3, 4, 5, 6))
def test_has_length(self):
self.assertEqual(len(ChainSequence([1, 2, 3], (4, 5, 6))), 6)
self.assertEqual(len(ChainSequence('hi', [0, 1, 2], (3, 4, 5))), 8)