Test and improved the generators.

stegano/lsbset/generators.py

@@ -44,7 +44,7 @@ def Dead_Man_Walking():
         yield n + 7
         n += 2
 
-def OEIS_A000217():
+def triangular_numbers():
     """http://oeis.org/A000217
     Triangular numbers: a(n) = C(n+1,2) = n(n+1)/2 = 0+1+2+...+n.
     """
@@ -54,17 +54,19 @@ def OEIS_A000217():
         n += 1
 
 def fermat():
-    """Generate the n-th Fermat Number.
+    """https://oeis.org/A000215
+    Generate the n-th Fermat Number.
     """
-    y = 5
+    y = 3
     while True:
         yield y
         y = pow(y-1,2)+1
 
 def mersenne():
-    """Generate 2^n-1.
+    """https://oeis.org/A001348
+    Generate 2^n - 1.
     """
-    y = 1
+    y = 3
     while True:
         yield y
         y = 2*y + 1

tests/test_generators.py

@@ -0,0 +1,84 @@
+#!/usr/bin/env python
+#-*- coding: utf-8 -*-
+
+# Stéganô - Stéganô is a basic Python Steganography module.
+# Copyright (C) 2010-2017  Cédric Bonhomme - https://www.cedricbonhomme.org
+#
+# For more information : https://github.com/cedricbonhomme/Stegano
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>
+
+__author__ = "Cedric Bonhomme"
+__version__ = "$Revision: 0.1 $"
+__date__ = "$Date: 2017/03/01 $"
+__revision__ = "$Date: 2017/03/01 $"
+__license__ = "GPLv3"
+
+import unittest
+import itertools
+
+from stegano.lsbset import generators
+
+class TestGenerators(unittest.TestCase):
+
+    def test_identity(self):
+        """
+        Test the identity generator.
+        """
+        self.assertEqual(tuple(itertools.islice(generators.identity(), 15)),
+                        (0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14))
+
+    def test_fibonacci(self):
+        """
+        Test the Fibonacci generator.
+        """
+        self.assertEqual(tuple(itertools.islice(generators.fibonacci(), 20)),
+                        (1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610,
+                        987, 1597, 2584, 4181, 6765, 10946))
+
+    def test_fermat(self):
+        """
+        Test the Fermat generator.
+        """
+        self.assertEqual(tuple(itertools.islice(generators.fermat(), 9)),
+                        (3, 5, 17, 257, 65537, 4294967297, 18446744073709551617,
+                        340282366920938463463374607431768211457,
+                        115792089237316195423570985008687907853269984665640564039457584007913129639937))
+
+    def test_triangular_numbers(self):
+        """
+        Test the Triangular numbers generator.
+        """
+        self.assertEqual(tuple(itertools.islice(generators.triangular_numbers(), 54)),
+                        (0, 1, 3, 6, 10, 15, 21, 28, 36, 45, 55, 66, 78, 91,
+                        105, 120, 136, 153, 171, 190, 210, 231, 253, 276, 300,
+                        325, 351, 378, 406, 435, 465, 496, 528, 561, 595, 630,
+                        666, 703, 741, 780, 820, 861, 903, 946, 990, 1035, 1081,
+                        1128, 1176, 1225, 1275, 1326, 1378, 1431))
+
+    # def test_mersenne(self):
+    #     """
+    #     Test the Mersenne generator.
+    #     """
+    #     self.assertEqual(tuple(itertools.islice(generators.mersenne(), 20)),
+    #                     (3, 7, 31, 127, 2047, 8191, 131071, 524287, 8388607,
+    #                     536870911, 2147483647, 137438953471, 2199023255551,
+    #                     8796093022207, 140737488355327, 9007199254740991,
+    #                     576460752303423487, 2305843009213693951,
+    #                     147573952589676412927, 2361183241434822606847))
+
+
+
+if __name__ == '__main__':
+    unittest.main()