def test_pattern_exists_in_string_and_returns_first_occurrence(self):
"""Test to confirm that if the pattern exists multiple times in the
string, that the Rabin-Karp algorithm returns the index of the first occurrence
of the pattern.
"""
self.assertTrue(self.pattern2 in self.string2)
self.assertTrue(self.string2.count(self.pattern2) > 1)
self.assertEqual(3, rabin_karp(self.pattern2, self.string2))
def test_rabin_karp(self):
self.assertEqual(3, rabin_karp("abc", "zsnabckfkd"))
self.assertEqual(None, rabin_karp("abc", "zsnajkskfkd"))
def test_pattern_exists_in_string(self):
"""Test to confirm that if the pattern exists in the string, that
the Rabin-Karp algorithm returns the starting index of the pattern.
"""
self.assertTrue(self.pattern1 in self.string1)
self.assertEqual(2, rabin_karp(self.pattern1, self.string1))
def test_pattern_not_in_string(self):
"""Test to confirm that if the pattern does not exist in the string
that the Rabin-Karp algorithm returns -1.
"""
self.assertTrue(self.pattern3 not in self.string3)
self.assertEqual(-1, rabin_karp(self.pattern3, self.string3))
def test_pattern_string_longer_than_large_string(self):
"""Test to confirm that if the pattern string is longer than the
large string that the Rabin-Karp algorithm returns -1.
"""
pattern = "a" * 20
self.assertEqual(-1, rabin_karp(pattern, self.string1))
def test_large_string_is_empty(self):
"""Test to confirm that if the large string is an empty string,
the Rabin-Karp algorithm returns -1.
"""
self.assertEqual(-1, rabin_karp(self.pattern1, ""))
def test_pattern_string_is_empty(self):
"""Test to confirm that if the pattern string is an empty string,
the Rabin-Karp algorithm returns -1.
"""
self.assertEqual(-1, rabin_karp("", self.string1))