yesod-test: url-encode addPostParam keys & values

Fixes #1616

yesod-test/Yesod/Test.hs

@@ -1242,8 +1242,9 @@ request reqBuilder = do
       BS8.concat $ separator : [BS8.concat [multipartPart p, separator] | p <- parts]
     multipartPart (ReqKvPart k v) = BS8.concat
       [ "Content-Disposition: form-data; "
-      , "name=\"", TE.encodeUtf8 k, "\"\r\n\r\n"
-      , TE.encodeUtf8 v, "\r\n"]
+      , "name=\"", enc k, "\"\r\n\r\n"
+      , enc v, "\r\n"]
+      where enc = H.urlEncode False . TE.encodeUtf8
     multipartPart (ReqFilePart k v bytes mime) = BS8.concat
       [ "Content-Disposition: form-data; "
       , "name=\"", TE.encodeUtf8 k, "\"; "
@@ -1266,14 +1267,14 @@ request reqBuilder = do
                           ([ ("Cookie", cookieValue) ] ++ headersForPostData rbdPostData)
                           method extraHeaders urlPath urlQuery)
         simpleRequestBody' (MultipleItemsPostData x) =
-          BSL8.fromChunks $ return $ TE.encodeUtf8 $ T.intercalate "&"
-          $ map singlepartPart x
+          BSL8.fromChunks $ return $ H.renderSimpleQuery False
+          $ concatMap singlepartPart x
         simpleRequestBody' (BinaryPostData x) = x
         cookieValue = Builder.toByteString $ Cookie.renderCookies cookiePairs
         cookiePairs = [ (Cookie.setCookieName c, Cookie.setCookieValue c)
                       | c <- map snd $ M.toList cookies ]
-        singlepartPart (ReqFilePart _ _ _ _) = ""
-        singlepartPart (ReqKvPart k v) = T.concat [k,"=",v]
+        singlepartPart (ReqFilePart _ _ _ _) = []
+        singlepartPart (ReqKvPart k v) = [(TE.encodeUtf8 k, TE.encodeUtf8 v)]
 
         -- If the request appears to be submitting a form (has key-value pairs) give it the form-urlencoded Content-Type.
         -- The previous behavior was to always use the form-urlencoded Content-Type https://github.com/yesodweb/yesod/issues/1063