Coverage for TransactionManager.attempts.

Note that we now raise ValueError if passed a non-positive count, rather
than asserting.

CHANGES.txt

@@ -4,6 +4,9 @@ Changes
 1.3.1 (unreleased)
 ------------------
 
+- Raise ValueError from ``TransactionManager.attempts`` if passed a
+  non-positive value (rather than using ``assert``).
+
 - Raise ValueError from ``TransactionManager.free`` if passed a foreign
   transaction (rather tna using ``assert``).
 

transaction/_manager.py

@@ -127,7 +127,8 @@ class TransactionManager(object):
         return self.get().savepoint(optimistic)
 
     def attempts(self, number=3):
-        assert number > 0
+        if number <= 0:
+            raise ValueError("number must be positive")
         while number:
             number -= 1
             if number:

transaction/tests/test__manager.py

@@ -209,6 +209,28 @@ class TransactionManagerTests(unittest.TestCase):
         tm.savepoint(True)
         self.assertTrue(txn._sp)
 
+    def test_attempts_w_invalid_count(self):
+        tm = self._makeOne()
+        self.assertRaises(ValueError, list, tm.attempts(0))
+        self.assertRaises(ValueError, list, tm.attempts(-1))
+        self.assertRaises(ValueError, list, tm.attempts(-10))
+
+    def test_attempts_w_valid_count(self):
+        tm = self._makeOne()
+        found = list(tm.attempts(1))
+        self.assertEqual(len(found), 1)
+        self.assertTrue(found[0] is tm)
+
+    def test_attempts_w_default_count(self):
+        from transaction._manager import Attempt
+        tm = self._makeOne()
+        found = list(tm.attempts())
+        self.assertEqual(len(found), 3)
+        for attempt in found[:-1]:
+            self.assertTrue(isinstance(attempt, Attempt))
+            self.assertTrue(attempt.manager is tm)
+        self.assertTrue(found[-1] is tm)
+
     # basic tests with two sub trans jars
     # really we only need one, so tests for
     # sub1 should identical to tests for sub2