bt_rpc: Added unit test to check for gatt service registration cycle

check if gatt services are correctly clean after remove

Signed-off-by: Robert Gałat <robert.galat@nordicsemi.no>

Author: RobertGalatNordic

subsys/bluetooth/rpc/common/bt_rpc_gatt_common.c

@@ -81,9 +81,14 @@ const struct bt_gatt_attr *bt_rpc_gatt_index_to_attr(uint32_t index)
 {
 	uint32_t service_index = index >> ATTR_INDEX_POS;
 	uint32_t attr_index = index & ATTR_INDEX_MASK;
-	const struct bt_gatt_service *service = svc_cache.services[service_index];
+	const struct bt_gatt_service *service;
+
+	if (service_index >= svc_cache.count) {
+		return NULL;
+	}
 
-	if ((service_index >= svc_cache.count) || (attr_index >= service->attr_count)) {
+	service = svc_cache.services[service_index];
+	if (!service || (attr_index >= service->attr_count)) {
 		return NULL;
 	}
 
@@ -203,7 +208,7 @@ void bt_rpc_gatt_foreach_attr_type(uint16_t start_handle, uint16_t end_handle,
 		}
 
 		for (size_t j = 0; j < svc->attr_count; j++) {
-			struct bt_gatt_attr *attr = &svc->attrs[j];
+			const struct bt_gatt_attr *attr = &svc->attrs[j];
 
 			handle = bt_gatt_attr_get_handle(attr);
 

subsys/bluetooth/rpc/host/bt_rpc_gatt_host.c

@@ -729,6 +729,7 @@ static void bt_rpc_gatt_service_unregister_rpc_handler(const struct nrf_rpc_grou
 
 	svc = bt_rpc_gatt_get_service_by_index(svc_index);
 	if (!svc) {
+		LOG_ERR("Service unregister: Invalid service index %u", svc_index);
 		result = -EINVAL;
 	}
 

tests/subsys/bluetooth/rpc_gatt_service/CMakeLists.txt

@@ -0,0 +1,36 @@
+#
+# Copyright (c) 2025 Nordic Semiconductor ASA
+#
+# SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
+#
+
+cmake_minimum_required(VERSION 3.20.0)
+
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+project(bluetooth_rpc_gatt_service_test)
+
+FILE(GLOB app_sources src/*.c)
+
+# Remove log_stub.c from glob since we include it explicitly
+list(FILTER app_sources EXCLUDE REGEX ".*log_stub\\.c$")
+
+# Add src directory for test_config.h
+# Note: We're using the real zephyr/bluetooth/gatt.h now, so we don't need
+# to override it with a stub
+target_include_directories(app PRIVATE
+  ${CMAKE_CURRENT_SOURCE_DIR}/src
+  ${ZEPHYR_NRF_MODULE_DIR}/subsys/bluetooth/rpc/common
+)
+
+# Include the source file directly for unit testing
+target_sources(app PRIVATE
+  ${app_sources}
+  ${CMAKE_CURRENT_SOURCE_DIR}/src/log_stub.c
+  ${ZEPHYR_NRF_MODULE_DIR}/subsys/bluetooth/rpc/common/bt_rpc_gatt_common.c
+)
+
+# Include test config header before compilation to define config values
+# that aren't available via Kconfig without CONFIG_BT_RPC
+target_compile_options(app PRIVATE
+  -include ${CMAKE_CURRENT_SOURCE_DIR}/src/test_config.h
+)

tests/subsys/bluetooth/rpc_gatt_service/prj.conf

@@ -0,0 +1,12 @@
+CONFIG_ZTEST=y
+
+# Minimal BT configuration - just enough to use the real gatt.h header
+# We don't need full BT stack functionality, just the type definitions
+CONFIG_BT=y
+
+# Minimal configuration for testing service cache only
+# Note: CONFIG_BT_RPC_GATT_SRV_MAX and CONFIG_BT_RPC_LOG_LEVEL are defined
+# via compile definitions in CMakeLists.txt since they require CONFIG_BT_RPC
+
+# Logging (minimal)
+CONFIG_LOG=y

tests/subsys/bluetooth/rpc_gatt_service/src/log_stub.c

@@ -0,0 +1,13 @@
+/*
+ * Copyright (c) 2025 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
+ *
+ * Stub implementation for logging module to avoid linker errors
+ * when testing without full BT RPC stack
+ */
+
+#include <zephyr/logging/log.h>
+
+/* Stub the log constant structure that's normally generated */
+LOG_MODULE_REGISTER(BT_RPC, 4);