Handle Cookies correctly for RunStreamingClient

Makes `performWithStreamingRequest` take into consideration the
CookieJar, which it previously didn't.

It's now possible to e.g. use the servant-client generated functions to
access a streaming endpoint that depends on a cookie being set to
authenticate the user

Fixes #1605

changelog.d/1606

@@ -0,0 +1,10 @@
+synopsis: Handle Cookies correctly for RunStreamingClient
+prs: #1606
+issues: #1605
+
+description: {
+
+Makes performWithStreamingRequest take into consideration the
+CookieJar, which it previously didn't.
+
+}

servant-client/src/Servant/Client/Internal/HttpClient/Streaming.hs

@@ -174,10 +174,21 @@ performRequest acceptStatus req = do
 -- | TODO: support UVerb ('acceptStatus' argument, like in 'performRequest' above).
 performWithStreamingRequest :: Request -> (StreamingResponse -> IO a) -> ClientM a
 performWithStreamingRequest req k = do
-  m <- asks manager
-  burl <- asks baseUrl
-  createClientRequest <- asks makeClientRequest
-  request <- liftIO $ createClientRequest burl req
+  ClientEnv m burl cookieJar' createClientRequest <- ask
+  clientRequest <- liftIO $ createClientRequest burl req
+  request <- case cookieJar' of
+    Nothing -> pure clientRequest
+    Just cj -> liftIO $ do
+      now <- getCurrentTime
+      atomically $ do
+        oldCookieJar <- readTVar cj
+        let (newRequest, newCookieJar) =
+              Client.insertCookiesIntoRequest
+                clientRequest
+                oldCookieJar
+                now
+        writeTVar cj newCookieJar
+        pure newRequest
   ClientM $ lift $ lift $ Codensity $ \k1 ->
       Client.withResponse request m $ \res -> do
           let status = Client.responseStatus res