Enable resetting factory.fuzzy's random generator (Closes #175, #185).

Users may now call ``factory.fuzzy.get_random_state()`` to retrieve
the current random generator's state (isolated from the one used in
Python's ``random``).

That state can then be reinjected with
``factory.fuzzy.set_random_state(state)``.

1 files changed, 36 insertions, 14 deletions

diff --git a/tests/test_fuzzy.py b/tests/test_fuzzy.py
index 1caeb0a..fd32705 100644
--- a/tests/test_fuzzy.py
+++ b/tests/test_fuzzy.py
@@ -55,7 +55,7 @@ class FuzzyChoiceTestCase(unittest.TestCase):
 
         d = fuzzy.FuzzyChoice(options)
 
-        with mock.patch('random.choice', fake_choice):
+        with mock.patch('factory.fuzzy._random.choice', fake_choice):
             res = d.evaluate(2, None, False)
 
         self.assertEqual(6, res)
@@ -93,7 +93,7 @@ class FuzzyIntegerTestCase(unittest.TestCase):
 
         fuzz = fuzzy.FuzzyInteger(2, 8)
 
-        with mock.patch('random.randrange', fake_randrange):
+        with mock.patch('factory.fuzzy._random.randrange', fake_randrange):
             res = fuzz.evaluate(2, None, False)
 
         self.assertEqual((2 + 8 + 1) * 1, res)
@@ -103,7 +103,7 @@ class FuzzyIntegerTestCase(unittest.TestCase):
 
         fuzz = fuzzy.FuzzyInteger(8)
 
-        with mock.patch('random.randrange', fake_randrange):
+        with mock.patch('factory.fuzzy._random.randrange', fake_randrange):
             res = fuzz.evaluate(2, None, False)
 
         self.assertEqual((0 + 8 + 1) * 1, res)
@@ -113,7 +113,7 @@ class FuzzyIntegerTestCase(unittest.TestCase):
 
         fuzz = fuzzy.FuzzyInteger(5, 8, 3)
 
-        with mock.patch('random.randrange', fake_randrange):
+        with mock.patch('factory.fuzzy._random.randrange', fake_randrange):
             res = fuzz.evaluate(2, None, False)
 
         self.assertEqual((5 + 8 + 1) * 3, res)
@@ -146,7 +146,7 @@ class FuzzyDecimalTestCase(unittest.TestCase):
 
         fuzz = fuzzy.FuzzyDecimal(2.0, 8.0)
 
-        with mock.patch('random.uniform', fake_uniform):
+        with mock.patch('factory.fuzzy._random.uniform', fake_uniform):
             res = fuzz.evaluate(2, None, False)
 
         self.assertEqual(decimal.Decimal('10.0'), res)
@@ -156,7 +156,7 @@ class FuzzyDecimalTestCase(unittest.TestCase):
 
         fuzz = fuzzy.FuzzyDecimal(8.0)
 
-        with mock.patch('random.uniform', fake_uniform):
+        with mock.patch('factory.fuzzy._random.uniform', fake_uniform):
             res = fuzz.evaluate(2, None, False)
 
         self.assertEqual(decimal.Decimal('8.0'), res)
@@ -166,7 +166,7 @@ class FuzzyDecimalTestCase(unittest.TestCase):
 
         fuzz = fuzzy.FuzzyDecimal(8.0, precision=3)
 
-        with mock.patch('random.uniform', fake_uniform):
+        with mock.patch('factory.fuzzy._random.uniform', fake_uniform):
             res = fuzz.evaluate(2, None, False)
 
         self.assertEqual(decimal.Decimal('8.001').quantize(decimal.Decimal(10) ** -3), res)
@@ -214,7 +214,7 @@ class FuzzyDateTestCase(unittest.TestCase):
         fake_randint = lambda low, high: (low + high) // 2
         fuzz = fuzzy.FuzzyDate(self.jan1, self.jan31)
 
-        with mock.patch('random.randint', fake_randint):
+        with mock.patch('factory.fuzzy._random.randint', fake_randint):
             res = fuzz.evaluate(2, None, False)
 
         self.assertEqual(datetime.date(2013, 1, 16), res)
@@ -225,7 +225,7 @@ class FuzzyDateTestCase(unittest.TestCase):
             fuzz = fuzzy.FuzzyDate(self.jan1)
 
         fake_randint = lambda low, high: (low + high) // 2
-        with mock.patch('random.randint', fake_randint):
+        with mock.patch('factory.fuzzy._random.randint', fake_randint):
             res = fuzz.evaluate(2, None, False)
 
         self.assertEqual(datetime.date(2013, 1, 2), res)
@@ -332,7 +332,7 @@ class FuzzyNaiveDateTimeTestCase(unittest.TestCase):
         fake_randint = lambda low, high: (low + high) // 2
         fuzz = fuzzy.FuzzyNaiveDateTime(self.jan1, self.jan31)
 
-        with mock.patch('random.randint', fake_randint):
+        with mock.patch('factory.fuzzy._random.randint', fake_randint):
             res = fuzz.evaluate(2, None, False)
 
         self.assertEqual(datetime.datetime(2013, 1, 16), res)
@@ -343,7 +343,7 @@ class FuzzyNaiveDateTimeTestCase(unittest.TestCase):
             fuzz = fuzzy.FuzzyNaiveDateTime(self.jan1)
 
         fake_randint = lambda low, high: (low + high) // 2
-        with mock.patch('random.randint', fake_randint):
+        with mock.patch('factory.fuzzy._random.randint', fake_randint):
             res = fuzz.evaluate(2, None, False)
 
         self.assertEqual(datetime.datetime(2013, 1, 2), res)
@@ -450,7 +450,7 @@ class FuzzyDateTimeTestCase(unittest.TestCase):
         fake_randint = lambda low, high: (low + high) // 2
         fuzz = fuzzy.FuzzyDateTime(self.jan1, self.jan31)
 
-        with mock.patch('random.randint', fake_randint):
+        with mock.patch('factory.fuzzy._random.randint', fake_randint):
             res = fuzz.evaluate(2, None, False)
 
         self.assertEqual(datetime.datetime(2013, 1, 16, tzinfo=compat.UTC), res)
@@ -461,7 +461,7 @@ class FuzzyDateTimeTestCase(unittest.TestCase):
             fuzz = fuzzy.FuzzyDateTime(self.jan1)
 
         fake_randint = lambda low, high: (low + high) // 2
-        with mock.patch('random.randint', fake_randint):
+        with mock.patch('factory.fuzzy._random.randint', fake_randint):
             res = fuzz.evaluate(2, None, False)
 
         self.assertEqual(datetime.datetime(2013, 1, 2, tzinfo=compat.UTC), res)
@@ -486,7 +486,7 @@ class FuzzyTextTestCase(unittest.TestCase):
 
         chars = ['a', 'b', 'c']
         fuzz = fuzzy.FuzzyText(prefix='pre', suffix='post', chars=chars, length=4)
-        with mock.patch('random.choice', fake_choice):
+        with mock.patch('factory.fuzzy._random.choice', fake_choice):
             res = fuzz.evaluate(2, None, False)
 
         self.assertEqual('preaaaapost', res)
@@ -504,3 +504,25 @@ class FuzzyTextTestCase(unittest.TestCase):
 
         for char in res:
             self.assertIn(char, ['a', 'b', 'c'])
+
+
+class FuzzyRandomTestCase(unittest.TestCase):
+    def test_seeding(self):
+        fuzz = fuzzy.FuzzyInteger(1, 1000)
+
+        fuzzy.reseed_random(42)
+        value = fuzz.evaluate(sequence=1, obj=None, create=False)
+
+        fuzzy.reseed_random(42)
+        value2 = fuzz.evaluate(sequence=1, obj=None, create=False)
+        self.assertEqual(value, value2)
+
+    def test_reset_state(self):
+        fuzz = fuzzy.FuzzyInteger(1, 1000)
+
+        state = fuzzy.get_random_state()
+        value = fuzz.evaluate(sequence=1, obj=None, create=False)
+
+        fuzzy.set_random_state(state)
+        value2 = fuzz.evaluate(sequence=1, obj=None, create=False)
+        self.assertEqual(value, value2)