fix(qr): close the gateway connection on errors

internal/ui/login/model.go

@@ -79,12 +79,14 @@ func (m Model) View() tview.Element {
 }
 
 func (m Model) Update(msg tview.Msg) (Model, tview.Cmd) {
+	var errCmd tview.Cmd
 	switch msg := msg.(type) {
 	case selectTabMsg:
 		m.active = tab(msg)
 		return m, m.Init()
 	case error:
-		return m, showErrorDialog(msg)
+		// The active tab still gets the error, so the QR tab can close its connection.
+		errCmd = showErrorDialog(msg)
 	case copyErrorMsg:
 		return m, setClipboard(string(msg))
 	}
@@ -98,7 +100,7 @@ func (m Model) Update(msg tview.Msg) (Model, tview.Cmd) {
 	case tokenTab:
 		m.token, cmd = m.token.Update(msg)
 	}
-	return m, cmd
+	return m, tview.Batch(errCmd, cmd)
 }
 
 func showErrorDialog(err error) tview.Cmd {

internal/ui/login/qr/conn_test.go

@@ -105,3 +105,31 @@ func TestModelGateway(t *testing.T) {
 		}
 	})
 }
+
+func TestCloseConn(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		conn, err := (&websocket.Upgrader{}).Upgrade(w, r, nil)
+		if err != nil {
+			t.Error(err)
+			return
+		}
+		defer conn.Close()
+		_, _, _ = conn.ReadMessage()
+	}))
+	t.Cleanup(server.Close)
+	ws, _, err := websocket.DefaultDialer.Dial("ws"+strings.TrimPrefix(server.URL, "http"), nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	conn := &gatewayConn{ws: ws}
+
+	// Closing twice must not error, or the error case would close it again forever.
+	for range 2 {
+		if msg := closeConn(conn)(); msg != (connCloseMsg{}) {
+			t.Fatalf("closeConn() = %#v, want connCloseMsg", msg)
+		}
+	}
+	if msg := listen(conn)(); msg != nil {
+		t.Fatalf("listen() after close = %#v, want nil", msg)
+	}
+}

internal/ui/login/qr/msg.go

@@ -8,6 +8,8 @@ import (
 	"encoding/base64"
 	json "encoding/json/v2"
 	"errors"
+	"log/slog"
+	"net"
 	"strings"
 	"sync"
 	"time"
@@ -57,9 +59,10 @@ func connect() tview.Cmd {
 
 func closeConn(conn *gatewayConn) tview.Cmd {
 	return func() tview.Msg {
+		// An error here must not reach the error case, which would close the connection again.
 		if conn != nil {
 			if err := conn.ws.Close(); err != nil {
-				return err
+				slog.Error("failed to close remote auth gateway connection", "err", err)
 			}
 		}
 		return connCloseMsg{}
@@ -99,6 +102,10 @@ func listen(conn *gatewayConn) tview.Cmd {
 		}
 
 		_, data, err := conn.ws.ReadMessage()
+		if errors.Is(err, net.ErrClosed) {
+			// closeConn closed the connection.
+			return nil
+		}
 		if err != nil {
 			return err
 		}