Index: uspace/srv/hid/display/test/display.c
===================================================================
--- uspace/srv/hid/display/test/display.c	(revision 9e84d2c5a3c35725eebdbe42c5716609678174c6)
+++ uspace/srv/hid/display/test/display.c	(revision 60ebe63485bbcbfb67076c3cbe2c9ccf22dd6b00)
@@ -1,4 +1,4 @@
 /*
- * Copyright (c) 2019 Jiri Svoboda
+ * Copyright (c) 2022 Jiri Svoboda
  * All rights reserved.
  *
@@ -36,4 +36,5 @@
 #include "../seat.h"
 #include "../window.h"
+#include "../wmclient.h"
 
 PCUT_INIT;
@@ -47,4 +48,10 @@
 };
 
+static void test_ds_wmev_pending(void *);
+
+static ds_wmclient_cb_t test_ds_wmclient_cb = {
+	.ev_pending = test_ds_wmev_pending
+};
+
 static void test_ds_ev_pending(void *arg)
 {
@@ -53,4 +60,10 @@
 }
 
+static void test_ds_wmev_pending(void *arg)
+{
+	bool *called_cb = (bool *) arg;
+	*called_cb = true;
+}
+
 /** Display creation and destruction. */
 PCUT_TEST(display_create_destroy)
@@ -86,4 +99,28 @@
 
 	ds_client_destroy(client);
+	ds_display_destroy(disp);
+}
+
+/** Basic WM client operation. */
+PCUT_TEST(display_wmclient)
+{
+	ds_display_t *disp;
+	ds_wmclient_t *wmclient;
+	ds_wmclient_t *c0, *c1;
+	errno_t rc;
+
+	rc = ds_display_create(NULL, df_none, &disp);
+	PCUT_ASSERT_ERRNO_VAL(EOK, rc);
+
+	rc = ds_wmclient_create(disp, &test_ds_wmclient_cb, NULL, &wmclient);
+	PCUT_ASSERT_ERRNO_VAL(EOK, rc);
+
+	c0 = ds_display_first_wmclient(disp);
+	PCUT_ASSERT_EQUALS(c0, wmclient);
+
+	c1 = ds_display_next_wmclient(c0);
+	PCUT_ASSERT_NULL(c1);
+
+	ds_wmclient_destroy(wmclient);
 	ds_display_destroy(disp);
 }
@@ -150,4 +187,46 @@
 	wnd = ds_display_find_window(disp, w0->id + 1);
 	PCUT_ASSERT_NULL(wnd);
+
+	ds_window_destroy(w0);
+	ds_window_destroy(w1);
+	ds_seat_destroy(seat);
+	ds_client_destroy(client);
+	ds_display_destroy(disp);
+}
+
+/** Test ds_display_window_to_top() */
+PCUT_TEST(display_window_to_top)
+{
+	ds_display_t *disp;
+	ds_client_t *client;
+	ds_seat_t *seat;
+	ds_window_t *w0;
+	ds_window_t *w1;
+	display_wnd_params_t params;
+	bool called_cb = false;
+	errno_t rc;
+
+	rc = ds_display_create(NULL, df_none, &disp);
+	PCUT_ASSERT_ERRNO_VAL(EOK, rc);
+
+	rc = ds_client_create(disp, &test_ds_client_cb, &called_cb, &client);
+	PCUT_ASSERT_ERRNO_VAL(EOK, rc);
+
+	rc = ds_seat_create(disp, &seat);
+	PCUT_ASSERT_ERRNO_VAL(EOK, rc);
+
+	display_wnd_params_init(&params);
+	params.rect.p0.x = params.rect.p0.y = 0;
+	params.rect.p1.x = params.rect.p1.y = 100;
+
+	rc = ds_window_create(client, &params, &w0);
+	PCUT_ASSERT_ERRNO_VAL(EOK, rc);
+
+	rc = ds_window_create(client, &params, &w1);
+	PCUT_ASSERT_ERRNO_VAL(EOK, rc);
+
+	PCUT_ASSERT_EQUALS(w1, ds_display_first_window(disp));
+	ds_display_window_to_top(w0);
+	PCUT_ASSERT_EQUALS(w0, ds_display_first_window(disp));
 
 	ds_window_destroy(w0);