def test_string_with_one_digit_number_increments_properly(self):
self.assertEqual(increment_string('bar1'), 'bar2')
self.assertEqual(increment_string('foobar3'), 'foobar4')
def test_long_numbers_without_letters(self):
self.assertEqual(increment_string('8846662'), '8846663')
def test_string_without_numbers_add_one(self):
self.assertEqual(increment_string('foo'), 'foo1')
def test_works_empty_strings(self):
self.assertEqual(increment_string(''), '1')
def test_one_digit_number(self):
self.assertEqual(increment_string('1'), '2')
def test_string_ending_with_multiple_zeroes(self):
self.assertEqual(increment_string('hell0 world00'), 'hell0 world01')
self.assertEqual(increment_string('hell0 world000'), 'hell0 world001')
def test_numbers_beginning_with_zeroes(self):
self.assertEqual(increment_string('hell0 world01'), 'hell0 world02')
self.assertEqual(increment_string('hell0 world099'), 'hell0 world100')
self.assertEqual(increment_string('hell0 world09'), 'hell0 world10')
def test_numbers_in_middle_do_not_confuse_function(self):
self.assertEqual(increment_string('hell0 world999'), 'hell0 world1000')
def test_string_with_three_digit_number_increments_properly(self):
self.assertEqual(increment_string('hello world123'), 'hello world124')
self.assertEqual(increment_string('hello world999'), 'hello world1000')
def test_string_with_two_digit_number_increments_properly(self):
self.assertEqual(increment_string('hello world12'), 'hello world13')
self.assertEqual(increment_string('hello world19'), 'hello world20')