fix(zwapi): Add test for zwapi_connection_tx

Without (revert HEAD~1) the previous fix change,
the test should segfault.

Note that it has been observed thats smaller buffers overflows
are not causing segfault.

Origin: SiliconLabsSoftware#127
Bug-SiliconLabs: UIC-3666
Bug-SLVDBBP: 3169925
Signed-off-by: Philippe Coval <[email protected]>

Author: rzr

applications/zpc/components/zwave_api/test/CMakeLists.txt

@@ -59,3 +59,13 @@ EXCLUDE zwapi_connection.c
         zwapi_session.c
         zwapi_init.c
 )
+
+target_add_unittest(zwave_api
+NAME zwapi_connection_test
+SOURCES zwapi_connection_test.c
+        zwapi_internal_init_mock.c
+DEPENDS zwapi_internal_mock
+        zwave_api_mock
+EXCLUDE zwapi_session.c
+        zwapi_init.c
+)

applications/zpc/components/zwave_api/test/zwapi_connection_test.c

@@ -0,0 +1,77 @@
+/******************************************************************************
+ * # License
+ * <b>Copyright 2025 Silicon Laboratories Inc. www.silabs.com</b>
+ ******************************************************************************
+ * The licensor of this software is Silicon Laboratories Inc. Your use of this
+ * software is governed by the terms of Silicon Labs Master Software License
+ * Agreement (MSLA) available at
+ * www.silabs.com/about-us/legal/master-software-license-agreement. This
+ * software is distributed to you in Source Code format and is governed by the
+ * sections of the MSLA applicable to Source Code.
+ *
+ *****************************************************************************/
+#include "unity.h"
+//#include "zwapi_protocol_basis.h"
+//#include "zwapi_func_ids.h"
+
+// Session mock:2
+#include "zwapi_session_mock.h"
+
+#include <unity.h>
+#include "zwapi_connection.h"
+
+#ifdef __clang__
+#pragma clang diagnostic ignored "-Woverflow"
+#endif
+
+#ifdef __GNUC__
+#pragma GCC diagnostic ignored "-Woverflow"
+#endif
+
+/// Setup the test suite (called once before all test_xxx functions are called)
+void suiteSetUp() {}
+
+/// Teardown the test suite (called once after all test_xxx functions are called)
+int suiteTearDown(int num_failures)
+{
+  return num_failures;
+}
+
+/// Called before each and every test
+void setUp() {}
+
+void test_zwapi_connection_tx_invalid_payload_length()
+{
+    uint8_t cmd = 0x01;
+    uint8_t type = 0x02;
+    uint8_t buffer[8 * 1024 * 1024] = {0}; //< Exceeding the maximum allowed payload length
+    uint8_t len = sizeof(buffer);
+    bool ack_needed = true;
+
+    // Expect the function to not crash
+    zwapi_connection_tx(cmd, type, buffer, len, ack_needed);
+}
+
+void test_zwapi_connection_tx_valid_inputs()
+{
+    uint8_t cmd = 0x01;
+    uint8_t type = 0x02;
+    uint8_t buffer[10] = {0x10, 0x20, 0x30, 0x40, 0x50, 0x60, 0x70, 0x80, 0x90, 0xA0};
+    uint8_t len = sizeof(buffer);
+    bool ack_needed = true;
+
+    // Expect the function to execute without errors
+    zwapi_connection_tx(cmd, type, buffer, len, ack_needed);
+}
+
+void test_zwapi_connection_tx_null_buffer()
+{
+    uint8_t cmd = 0x01;
+    uint8_t type = 0x02;
+    uint8_t *buffer = NULL;
+    uint8_t len = 0;
+    bool ack_needed = true;
+
+    // Expect the function to not crash
+    zwapi_connection_tx(cmd, type, buffer, len, ack_needed);
+}