cookies: Take a less cowardly approach

Per discussion with @sigmavirus24, we'll take the less cowardly approach here.
"the RFC defines the Expires header as a string with the format we're assigning to ``time_template`` so checking if it is a string is unnecessary."

Crossing my fingers that this doesn't break anyones existing code...

requests/cookies.py

@@ -378,31 +378,28 @@ def create_cookie(name, value, **kwargs):
 
 def morsel_to_cookie(morsel):
     """Convert a Morsel object into a Cookie containing the one k/v pair."""
+
     expires = None
-    if morsel["max-age"]:
-        expires = time.time() + morsel["max-age"]
+    if morsel['max-age']:
+        expires = time.time() + morsel['max-age']
     elif morsel['expires']:
-        expires = morsel['expires']
-        try:
-            time_template = "%a, %d-%b-%Y %H:%M:%S GMT"
-            expires = time.mktime(time.strptime(expires, time_template))
-        except TypeError:
-            pass
-    c = create_cookie(
-        name=morsel.key,
-        value=morsel.value,
-        version=morsel['version'] or 0,
-        port=None,
-        domain=morsel['domain'],
-        path=morsel['path'],
-        secure=bool(morsel['secure']),
-        expires=expires,
-        discard=False,
+        time_template = '%a, %d-%b-%Y %H:%M:%S GMT'
+        expires = time.mktime(time.strptime(morsel['expires'], time_template))
+    return create_cookie(
         comment=morsel['comment'],
         comment_url=bool(morsel['comment']),
+        discard=False,
+        domain=morsel['domain'],
+        expires=expires,
+        name=morsel.key,
+        path=morsel['path'],
+        port=None,
         rest={'HttpOnly': morsel['httponly']},
-        rfc2109=False,)
-    return c
+        rfc2109=False,
+        secure=bool(morsel['secure']),
+        value=morsel.value,
+        version=morsel['version'] or 0,
+    )
 
 
 def cookiejar_from_dict(cookie_dict, cookiejar=None, overwrite=True):

test_requests.py

@@ -760,24 +760,6 @@ class RequestsTestCase(unittest.TestCase):
             preq = req.prepare()
             assert test_url == preq.url
 
-    def test_morsel_to_cookie_expires_is_converted(self):
-        morsel = Morsel()
-
-        # Test case where we convert from string time
-        morsel['expires'] = 'Thu, 01-Jan-1970 00:00:01 GMT'
-        cookie = morsel_to_cookie(morsel)
-        self.assertEquals(cookie.expires, 18001)
-
-        # Test case where no conversion is required
-        morsel['expires'] = 100
-        cookie = morsel_to_cookie(morsel)
-        self.assertEquals(cookie.expires, 100)
-
-        # Test case where an invalid string is input
-        morsel['expires'] = 'woops'
-        with self.assertRaises(ValueError):
-            cookie = morsel_to_cookie(morsel)
-
 
 class TestContentEncodingDetection(unittest.TestCase):
 
@@ -1023,5 +1005,61 @@ class UtilsTestCase(unittest.TestCase):
         assert not address_in_network('172.16.0.1', '192.168.1.0/24')
 
 
+
+class TestMorselToCookieExpires(unittest.TestCase):
+
+    """Tests for morsel_to_cookie when morsel contains expires."""
+
+    def test_expires_valid_str(self):
+        """Test case where we convert expires from string time."""
+
+        morsel = Morsel()
+        morsel['expires'] = 'Thu, 01-Jan-1970 00:00:01 GMT'
+        cookie = morsel_to_cookie(morsel)
+        self.assertEquals(cookie.expires, 18001)
+
+    def test_expires_invalid_int(self):
+        """Test case where an invalid type is passed for expires."""
+
+        morsel = Morsel()
+        morsel['expires'] = 100
+        self.assertRaises(TypeError, morsel_to_cookie, (morsel))
+
+    def test_expires_invalid_str(self):
+        """Test case where an invalid string is input."""
+
+        morsel = Morsel()
+        morsel['expires'] = 'woops'
+        self.assertRaises(ValueError, morsel_to_cookie, (morsel))
+
+    def test_expires_none(self):
+        """Test case where expires is None."""
+
+        morsel = Morsel()
+        morsel['expires'] = None
+        cookie = morsel_to_cookie(morsel)
+        self.assertEquals(cookie.expires, None)
+
+
+class TestMorselToCookieMaxAge(unittest.TestCase):
+
+    """Tests for morsel_to_cookie when morsel contains max-age."""
+
+    def test_max_age_valid_int(self):
+        """Test case where a valid max age in seconds is passed."""
+
+        morsel = Morsel()
+        morsel['max-age'] = 60
+        cookie = morsel_to_cookie(morsel)
+        self.assertIsInstance(cookie.expires, int)
+
+    def test_max_age_invalid_str(self):
+        """Test case where a invalid max age is passed."""
+
+        morsel = Morsel()
+        morsel['max-age'] = 'woops'
+        self.assertRaises(TypeError, morsel_to_cookie, (morsel))
+
+
 if __name__ == '__main__':
     unittest.main()