Index: uspace/srv/hid/display/test/cfgclient.c
===================================================================
--- uspace/srv/hid/display/test/cfgclient.c	(revision 46b02cb1381abb734d570053a8c9d3992aecb1d7)
+++ uspace/srv/hid/display/test/cfgclient.c	(revision 46b02cb1381abb734d570053a8c9d3992aecb1d7)
@@ -0,0 +1,181 @@
+/*
+ * Copyright (c) 2023 Jiri Svoboda
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ * - The name of the author may not be used to endorse or promote products
+ *   derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <disp_srv.h>
+#include <errno.h>
+#include <pcut/pcut.h>
+#include <str.h>
+
+#include "../display.h"
+#include "../cfgclient.h"
+
+PCUT_INIT;
+
+PCUT_TEST_SUITE(cfgclient);
+
+static void test_ds_dcev_pending(void *);
+
+static ds_cfgclient_cb_t test_ds_cfgclient_cb = {
+	.ev_pending = test_ds_dcev_pending
+};
+
+static void test_ds_dcev_pending(void *arg)
+{
+	bool *called_cb = (bool *) arg;
+	*called_cb = true;
+}
+
+/** WM client creation and destruction. */
+PCUT_TEST(create_destroy)
+{
+	ds_display_t *disp;
+	ds_cfgclient_t *cfgclient;
+	errno_t rc;
+
+	rc = ds_display_create(NULL, df_none, &disp);
+	PCUT_ASSERT_ERRNO_VAL(EOK, rc);
+
+	rc = ds_cfgclient_create(disp, &test_ds_cfgclient_cb, NULL, &cfgclient);
+	PCUT_ASSERT_ERRNO_VAL(EOK, rc);
+
+	ds_cfgclient_destroy(cfgclient);
+	ds_display_destroy(disp);
+}
+
+/** Test ds_cfgclient_get_event(), ds_cfgclient_post_seat_added_event(). */
+PCUT_TEST(client_get_post_seat_added_event)
+{
+	ds_display_t *disp;
+	ds_cfgclient_t *cfgclient;
+	dispcfg_ev_t revent;
+	bool called_cb = NULL;
+	sysarg_t seat_id;
+	errno_t rc;
+
+	rc = ds_display_create(NULL, df_none, &disp);
+	PCUT_ASSERT_ERRNO_VAL(EOK, rc);
+
+	rc = ds_cfgclient_create(disp, &test_ds_cfgclient_cb, &called_cb,
+	    &cfgclient);
+	PCUT_ASSERT_ERRNO_VAL(EOK, rc);
+
+	called_cb = false;
+	seat_id = 42;
+
+	rc = ds_cfgclient_get_event(cfgclient, &revent);
+	PCUT_ASSERT_ERRNO_VAL(ENOENT, rc);
+
+	rc = ds_cfgclient_post_seat_added_event(cfgclient, seat_id);
+	PCUT_ASSERT_ERRNO_VAL(EOK, rc);
+	PCUT_ASSERT_TRUE(called_cb);
+
+	rc = ds_cfgclient_get_event(cfgclient, &revent);
+	PCUT_ASSERT_ERRNO_VAL(EOK, rc);
+	PCUT_ASSERT_EQUALS(seat_id, revent.seat_id);
+	PCUT_ASSERT_EQUALS(dcev_seat_added, revent.etype);
+
+	rc = ds_cfgclient_get_event(cfgclient, &revent);
+	PCUT_ASSERT_ERRNO_VAL(ENOENT, rc);
+
+	ds_cfgclient_destroy(cfgclient);
+	ds_display_destroy(disp);
+}
+
+/** Test ds_cfgclient_get_event(), ds_cfgclient_post_seat_removed_event(). */
+PCUT_TEST(client_get_post_seat_removed_event)
+{
+	ds_display_t *disp;
+	ds_cfgclient_t *cfgclient;
+	dispcfg_ev_t revent;
+	bool called_cb = NULL;
+	sysarg_t seat_id;
+	errno_t rc;
+
+	rc = ds_display_create(NULL, df_none, &disp);
+	PCUT_ASSERT_ERRNO_VAL(EOK, rc);
+
+	rc = ds_cfgclient_create(disp, &test_ds_cfgclient_cb, &called_cb,
+	    &cfgclient);
+	PCUT_ASSERT_ERRNO_VAL(EOK, rc);
+
+	called_cb = false;
+	seat_id = 42;
+
+	rc = ds_cfgclient_get_event(cfgclient, &revent);
+	PCUT_ASSERT_ERRNO_VAL(ENOENT, rc);
+
+	rc = ds_cfgclient_post_seat_removed_event(cfgclient, seat_id);
+	PCUT_ASSERT_ERRNO_VAL(EOK, rc);
+	PCUT_ASSERT_TRUE(called_cb);
+
+	rc = ds_cfgclient_get_event(cfgclient, &revent);
+	PCUT_ASSERT_ERRNO_VAL(EOK, rc);
+	PCUT_ASSERT_EQUALS(seat_id, revent.seat_id);
+	PCUT_ASSERT_EQUALS(dcev_seat_removed, revent.etype);
+
+	rc = ds_cfgclient_get_event(cfgclient, &revent);
+	PCUT_ASSERT_ERRNO_VAL(ENOENT, rc);
+
+	ds_cfgclient_destroy(cfgclient);
+	ds_display_destroy(disp);
+}
+
+/** Test ds_cfgclient_purge_events() */
+PCUT_TEST(purge_events)
+{
+	ds_display_t *disp;
+	ds_cfgclient_t *cfgclient;
+	dispcfg_ev_t revent;
+	bool called_cb = NULL;
+	sysarg_t seat_id;
+	errno_t rc;
+
+	rc = ds_display_create(NULL, df_none, &disp);
+	PCUT_ASSERT_ERRNO_VAL(EOK, rc);
+
+	rc = ds_cfgclient_create(disp, &test_ds_cfgclient_cb, &called_cb,
+	    &cfgclient);
+	PCUT_ASSERT_ERRNO_VAL(EOK, rc);
+
+	/* Post window added event */
+	seat_id = 42;
+	rc = ds_cfgclient_post_seat_added_event(cfgclient, seat_id);
+	PCUT_ASSERT_ERRNO_VAL(EOK, rc);
+
+	/* Purge it */
+	ds_cfgclient_purge_events(cfgclient);
+
+	/* The queue should be empty now */
+	rc = ds_cfgclient_get_event(cfgclient, &revent);
+	PCUT_ASSERT_ERRNO_VAL(ENOENT, rc);
+
+	ds_cfgclient_destroy(cfgclient);
+	ds_display_destroy(disp);
+}
+
+PCUT_EXPORT(cfgclient);