def test_first_range_no_predicate(self):
e = Enumerable(range(10))
result = e.first()
self.assertEqual(result, 0)
def test_first_dict_predicate_not_exists(self):
d = {'a': 1, 'b': 2}
e = Enumerable(d)
result = e.first(lambda x: x > 'z')
self.assertIsNone(result)
def test_first_dict_empty(self):
d = dict()
e = Enumerable(d)
result = e.first()
self.assertIsNone(result)
def test_first_dict_predicate_exists(self):
d = {'a': 1, 'b': 2}
e = Enumerable(d)
result = e.first(lambda x: x != 'a')
self.assertEqual(result, 'b')
def test_first_dict_no_predicate(self):
d = {'a': 1, 'b': 2}
e = Enumerable(d)
result = e.first()
self.assertIn(result, d.keys())
def test_first_range_predicate_no_match_default(self):
e = Enumerable(range(10))
result = e.first(lambda x: x == 'hello', default=False)
self.assertFalse(result)
def test_first_range_predicate_no_match(self):
e = Enumerable(range(10))
result = e.first(lambda x: x == 'hello')
self.assertIsNone(result)
def test_first_range_predicate_exists(self):
e = Enumerable(range(10))
result = e.first(lambda x: x > 6)
self.assertEqual(result, 7)
