Extend ConnectionPool.to_url to parse querystring arguments to correct type.

Previously if a value for socket_timeout was supplied as part fo the URL an error would be raised when a socket was created with an invalid type, this change fixes that by parsing `socket_timeout`, `socket_connect_timeout` to float values.
In addition the boolean values `socket_keepalive` and `retry_on_timeout` are parsed to bool types taking into account the usage of True/False, Yes/No strings.

2 files changed, 68 insertions, 4 deletions

diff --git a/redis/connection.py b/redis/connection.py
index 91730ea..fb90e93 100755
--- a/redis/connection.py
+++ b/redis/connection.py
@@ -735,6 +735,22 @@ class UnixDomainSocketConnection(Connection):
                 (exception.args[0], self.path, exception.args[1])
 
 
+def to_bool(value):
+    if value is None or value == '':
+        return None
+    if isinstance(value, basestring) and value.upper() in ('0', 'F', 'FALSE', 'N', 'NO'):
+        return False
+    return bool(value)
+
+
+URL_QUERY_PARAMETER_TYPES = {
+    'socket_timeout': float,
+    'socket_connect_timeout': float,
+    'socket_keepalive': to_bool,
+    'retry_on_timeout': to_bool
+}
+
+
 class ConnectionPool(object):
     "Generic connection pool"
     @classmethod
@@ -769,8 +785,13 @@ class ConnectionPool(object):
         ``path``, and ``password`` components.
 
         Any additional querystring arguments and keyword arguments will be
-        passed along to the ConnectionPool class's initializer. In the case
-        of conflicting arguments, querystring arguments always win.
+        passed along to the ConnectionPool class's initializer. The querystring
+        arguments ``socket_connect_timeout`` and ``socket_timeout`` if supplied
+        are parsed as float values. The arguments ``socket_keepalive`` and
+        ``retry_on_timeout`` are parsed to boolean values that accept
+        True/False, Yes/No values to indicate state. Invalid types cause a
+        ``UserWarning`` to be raised. In the case of conflicting arguments,
+        querystring arguments always win.
         """
         url_string = url
         url = urlparse(url)
@@ -790,7 +811,13 @@ class ConnectionPool(object):
 
         for name, value in iteritems(parse_qs(qs)):
             if value and len(value) > 0:
-                url_options[name] = value[0]
+                if name in URL_QUERY_PARAMETER_TYPES:
+                    try:
+                        url_options[name] = URL_QUERY_PARAMETER_TYPES[name](value[0])
+                    except (TypeError, ValueError):
+                        warnings.warn(UserWarning("Invalid value for `%s` in connection URL." % name))
+                else:
+                    url_options[name] = value[0]
 
         if decode_components:
             password = unquote(url.password) if url.password else None
diff --git a/tests/test_connection_pool.py b/tests/test_connection_pool.py
index 6b2478a..c36177f 100644
--- a/tests/test_connection_pool.py
+++ b/tests/test_connection_pool.py
@@ -6,7 +6,7 @@ import time
 import re
 
 from threading import Thread
-from redis.connection import ssl_available
+from redis.connection import ssl_available, to_bool
 from .conftest import skip_if_server_version_lt
 
 
@@ -237,6 +237,43 @@ class TestConnectionPoolURLParsing(object):
             'password': None,
         }
 
+    def test_extra_typed_querystring_options(self):
+        pool = redis.ConnectionPool.from_url(
+            'redis://localhost/2?socket_timeout=20&socket_connect_timeout=10&socket_keepalive=&retry_on_timeout=Yes')
+
+        assert pool.connection_class == redis.Connection
+        assert pool.connection_kwargs == {
+            'host': 'localhost',
+            'port': 6379,
+            'db': 2,
+            'socket_timeout': 20.0,
+            'socket_connect_timeout': 10.0,
+            'retry_on_timeout': True,
+            'password': None,
+        }
+
+    def test_boolean_parsing(self):
+        for expected, value in (
+                (None, None),
+                (None, ''),
+                (False, 0), (False, '0'),
+                (False, 'f'), (False, 'F'), (False, 'False'),
+                (False, 'n'), (False, 'N'), (False, 'No'),
+                (True, 1), (True, '1'),
+                (True, 'y'), (True, 'Y'), (True, 'Yes'),
+        ):
+            assert expected is to_bool(value)
+
+    def test_invalid_extra_typed_querystring_options(self):
+        import warnings
+        with warnings.catch_warnings(record=True) as warning_log:
+            redis.ConnectionPool.from_url('redis://localhost/2?socket_timeout=_&socket_connect_timeout=abc')
+        # Compare the message values
+        assert [str(m.message) for m in sorted(warning_log, key=lambda l: str(l.message))] == [
+            'Invalid value for `socket_connect_timeout` in connection URL.',
+            'Invalid value for `socket_timeout` in connection URL.',
+        ]
+
     def test_extra_querystring_options(self):
         pool = redis.ConnectionPool.from_url('redis://localhost?a=1&b=2')
         assert pool.connection_class == redis.Connection