WebSockets client: Add test and fix issues. (#109)

* Adds a test that uses a publicly available echo endpoint.
* Didn't correctly buffer data received in the same packet as the
headers.
* Wrongly sent two Host: headers.

src/client.toit

@@ -346,10 +346,9 @@ class Client:
     headers = headers ? headers.copy : Headers
     MAX_REDIRECTS.repeat:
       nonce := WebSocket.add_client_upgrade_headers_ headers
-      headers.add "Host" parsed.host_with_port
       response/Response? := null
       try_to_reuse_ parsed: | connection |
-        request := connection.new_request GET parsed.path headers
+        request/RequestOutgoing := connection.new_request GET parsed.path headers
         response = request.send
       if follow_redirects and
           (is_regular_redirect_ response.status_code

src/connection.toit

@@ -108,7 +108,7 @@ class Connection:
     else:
       // Return a writer that doesn't accept any data.
       body_writer = ContentLengthWriter this writer_ 0
-      if not headers.matches "Connection" "upgrade":
+      if not headers.matches "Connection" "Upgrade":
         headers.set "Content-Length" "0"
 
     // Set this before doing blocking operations on the socket, so that we
@@ -323,8 +323,8 @@ A $tcp.Socket doesn't support ungetting data that was already read for it, so we
 */
 class DetachedSocket_ implements tcp.Socket:
   socket_/tcp.Socket
-  buffered_/ByteArray? := null
-  constructor .socket_ buffered_:
+  buffered_/ByteArray? := ?
+  constructor .socket_ .buffered_:
 
   local_address -> net.SocketAddress:
     return socket_.local_address

src/web_socket.toit

@@ -245,10 +245,10 @@ class WebSocket:
     // The WebSocket nonce is not very important and does not need to be
     // cryptographically random.
     nonce := base64.encode (ByteArray 16: random 0x100)
-    headers.add "Connection" "Upgrade"
     headers.add "Upgrade" "websocket"
     headers.add "Sec-WebSocket-Key" nonce
     headers.add "Sec-WebSocket-Version" "13"
+    headers.add "Connection" "Upgrade"
     return nonce
 
   static check_client_upgrade_response_ response/Response nonce/string -> none:

tests/websocket_client_test.toit

@@ -0,0 +1,28 @@
+// Copyright (C) 2023 Toitware ApS.
+// Use of this source code is governed by a Zero-Clause BSD license that can
+// be found in the tests/TESTS_LICENSE file.
+
+import certificate_roots
+import expect show *
+import http
+import net
+
+URI ::= "wss://echo.websocket.events/"
+// This header is required by the WebSocket endpoint.
+ORIGIN ::= { "Origin": "http://echo.websocket.events" }
+MSG1 ::= "Hello, from Toit!"
+MSG2 ::= #[0xff, 0x00, 103]
+
+main:
+  network := net.open
+  client := http.Client network --root_certificates=[certificate_roots.ISRG_ROOT_X1]
+  web_socket := client.web_socket --uri=URI --headers=(http.Headers.from_map ORIGIN)
+  greeting := web_socket.receive
+  expect_equals "echo.websocket.events sponsored by Lob.com" greeting
+  print greeting
+  web_socket.send MSG1
+  echo := web_socket.receive
+  expect_equals MSG1 echo
+  web_socket.send MSG2
+  echo_bytes := web_socket.receive
+  expect_equals MSG2 echo_bytes