import unittest

from dalpy.hashing import HashTable

class HashTableSet(unittest.TestCase):

def test_empty(self):

t = HashTable()

self.assertFalse(t.contains_key('a'))

self.assertRaises(KeyError, lambda: t.get_value('a'))

self.assertRaises(KeyError, lambda: t.delete('a'))

self.assertTrue(t.keys().is_empty())

def test_insert(self):

t = HashTable()

t.insert('a', 1)

self.assertEqual(1, t.get_value('a'))

def test_contains(self):

t = HashTable()

t.insert('a', 1)

self.assertTrue(t.contains_key('a'))

def test_many_insert(self):

t = HashTable()

keys = ['a', 'b', 'c']

for i, k in enumerate(keys):

t.insert(k, i + 1)

for i, k in enumerate(keys):

self.assertTrue(t.contains_key(k))

self.assertEqual(i + 1, t.get_value(k))

def test_delete(self):

t = HashTable()

t.insert('a', 1)

self.assertEqual(1, t.delete('a'))

self.assertRaises(KeyError, lambda: t.delete('a'))

def test_many_delete(self):

t = HashTable()

keys = ['a', 'b', 'c']

for i, k in enumerate(keys):

t.insert(k, i + 1)

for i, k in enumerate(keys):

self.assertEqual(i + 1, t.delete(k))

self.assertFalse(t.contains_key(k))

def test_duplicates(self):

t = HashTable()

t.insert('a', 1)

t.insert('a', 2)

self.assertEqual(2, t.get_value('a'))

self.assertEqual(2, t.delete('a'))

self.assertRaises(KeyError, lambda: t.delete('a'))

def test_add_none(self):

t = HashTable()

t.insert('a', None)

self.assertTrue(t.contains_key('a'))

self.assertIsNone(t.get_value('a'))

self.assertIsNone(t.delete('a'))

def test_keys(self):

t = HashTable()

t.insert('a', None)

t.insert('b', None)

keys = t.keys()

self.assertTrue('a' in keys)

self.assertTrue('b' in keys)

if __name__ == '__main__':

unittest.main()