import unittest

from stack import Stack, EmptyStackException

class TestStack(unittest.TestCase):

def setUp(self):

self.stack = Stack()

def test_is_empty(self):

self.assertTrue(self.stack.is_empty())

def test_str_and_push(self):

self.stack.push(6)

self.assertEqual(str(self.stack),"[6]")

def test_push_three_elements(self):

self.stack.push(3)

self.stack.push(2)

self.stack.push(1)

self.assertEqual(str(self.stack),"[1, 2, 3]")

def test_pop_exception(self):

with self.assertRaises(EmptyStackException):

self.stack.pop()

def test_pop_with_one_element(self):

self.stack.push("Item")

self.assertEqual(self.stack.pop(),"Item")

self.assertTrue(self.stack.is_empty())

def test_pop_with_two_elements(self):

self.stack.push(2)

self.stack.push(1)

self.assertEqual(self.stack.pop(),1)

self.assertEqual(str(self.stack),'[2]')

def test_peek_exception(self):

with self.assertRaises(EmptyStackException):

self.stack.peek()

def test_peek(self):

self.stack.push(1)

self.assertEqual(self.stack.peek(),1)

def test_size(self):

self.assertEqual(self.stack.size(),0)

self.stack.push(1)

self.stack.push(2)

self.stack.push(3)

self.assertEqual(self.stack.size(),3)

if __name__ == '__main__':

unittest.main()