Fix flaky TestResizeTerminal

lib/backend/buffer.go

@@ -277,10 +277,10 @@ func (c *CircularBuffer) removeWatcherWithLock(watcher *BufferWatcher) {
 		c.Warningf("Internal logic error: %v.", trace.DebugReport(trace.BadParameter("empty watcher")))
 		return
 	}
-	c.Debugf("Removing watcher %p via external close.", watcher)
+	c.Debugf("Removing watcher %v (%p) via external close.", watcher.Name, watcher)
 	found := c.watchers.rm(watcher)
 	if !found {
-		c.Debugf("Could not find watcher %v.", watcher)
+		c.Debugf("Could not find watcher %v.", watcher.Name)
 	}
 }
 

lib/web/apiserver_test.go

@@ -1642,7 +1642,13 @@ func TestResizeTerminal(t *testing.T) {
 	require.NoError(t, err)
 	t.Cleanup(func() { require.NoError(t, ws1.Close()) })
 
-	// Create a new user "bar", open a terminal to the session created above
+	// Wait for session to have started
+	require.Eventually(t, func() bool {
+		_, err := s.server.Auth().GetSessionTracker(context.Background(), sess.ID.String())
+		return err == nil
+	}, 3*time.Second, 200*time.Millisecond, "session not available")
+
+	// Create a new user "bar" and join the session created above
 	pack2 := s.authPack(t, "bar")
 	ws2, sess2, err := s.makeTerminal(t, pack2, withSessionID(sess.ID), withParticipantMode(types.SessionPeerMode))
 	require.NoError(t, err)
@@ -1688,7 +1694,7 @@ t1ready:
 	select {
 	case e := <-ws2Messages:
 		if isResizeEventEnvelope(e) {
-			require.FailNow(t, "terminal 2 should not have received a resize event")
+			require.FailNow(t, "terminal 2 should not have received a resize event: %v", e)
 		}
 	case err := <-errs:
 		require.NoError(t, err)
@@ -1927,9 +1933,9 @@ func TestTerminalNameResolution(t *testing.T) {
 	t.Cleanup(cancel)
 
 	// Wait for the node to be registered as the registration is asynchronous.
-	require.Eventuallyf(t, func() bool {
+	require.Eventually(t, func() bool {
 		nodes, err := s.proxyClient.GetNodes(ctx, "default")
-		require.NoError(t, err)
+		assert.NoError(t, err)
 
 		return len(nodes) == 2 // one created by default and llama
 	}, 5*time.Second, 200*time.Millisecond, "failed to register node")
@@ -7242,7 +7248,14 @@ func (s *WebSuite) makeTerminal(t *testing.T, pack *authPack, opts ...terminalOp
 
 	ws, resp, err := dialer.Dial(u.String(), header)
 	if err != nil {
-		return nil, nil, trace.Wrap(err)
+		var sb strings.Builder
+		sb.WriteString("websocket dial")
+		if resp != nil {
+			fmt.Fprintf(&sb, "; status code %v;", resp.StatusCode)
+			fmt.Fprintf(&sb, "headers: %v; body: ", resp.Header)
+			io.Copy(&sb, resp.Body)
+		}
+		return nil, nil, trace.Wrap(err, sb.String())
 	}
 
 	ty, raw, err := ws.ReadMessage()