Function prepare_connect_request

src/websockets/proxy.py:134–150

(
    proxy: Proxy,
    ws_uri: WebSocketURI,
    user_agent_header: str | None = USER_AGENT,
)

def prepare_connect_request(
    proxy: Proxy,
    ws_uri: WebSocketURI,
    user_agent_header: str | None = USER_AGENT,
) -> bytes:
    host = build_host(ws_uri.host, ws_uri.port, ws_uri.secure, always_include_port=True)
    headers = Headers()
    headers["Host"] = build_host(ws_uri.host, ws_uri.port, ws_uri.secure)
    if user_agent_header is not None:
        headers["User-Agent"] = user_agent_header
    if proxy.username is not None:
        assert proxy.password is not None  # enforced by parse_proxy()
        headers["Proxy-Authorization"] = build_authorization_basic(
            proxy.username, proxy.password
        )
    # We cannot use the Request class because it supports only GET requests.
    return f"CONNECT {host} HTTP/1.1\r\n".encode() + headers.serialize()