Add test for printing the todos.

Make sure the content is preserved byte by byte.

TodoBase.py

@@ -161,4 +161,4 @@ class TodoBase(object):
 
     def __str__(self):
         """ A printer for the todo item. """
-        print self.source() + "\n"
+        return self.source()

TodoList.py

@@ -99,12 +99,9 @@ class TodoList(object):
         defined by the end user. Todos is this list should not be modified,
         modifications should occur through this class.
         """
+        # TODO: perhaps change list such that values are immutable?
         return p_filter.filter(p_sorter.sort(self._todos))
 
     def __str__(self):
-        result = ""
-        for todo in self._todos:
-            result = "%s" % todo
-
-        return result
+        return '\n'.join([str(x) for x in self._todos])
 

test/TodoListTest.py

@@ -9,7 +9,9 @@ import TodoList
 class TodoListTester(unittest.TestCase):
     def setUp(self):
         self.todofile = TodoFile.TodoFile('TodoListTest.txt')
-        self.todolist = TodoList.TodoList(self.todofile.read())
+        lines = self.todofile.read()
+        self.text = ''.join(lines)
+        self.todolist = TodoList.TodoList(lines)
 
     def test_contexts(self):
         self.assertEquals(set(['Context1', 'Context2']), \
@@ -78,3 +80,9 @@ class TodoListTester(unittest.TestCase):
         self.assertTrue(self.todolist.todo(1).is_completed())
         self.assertEquals(self.todolist.todo(1).source(), \
             "x " + today + " Foo @Context1 Not@Context +Project1 Not+Project")
+
+    def test_string(self):
+        # readlines() always ends a string with \n, but join() in str(todolist)
+        # doesn't necessarily.
+        self.assertEquals(str(self.todolist) + '\n', self.text)
+