add missing network frame test;

tests/nxdn/NetworkFrame_Tests.cpp

@@ -0,0 +1,75 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Digital Voice Modem - Test Suite
+ * GPLv2 Open Source. Use is subject to license terms.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES FROM THIS FILE HEADER.
+ *
+ *  Copyright (C) 2026 Bryan Biedenkapp, N2PLL
+ */
+
+#include "common/network/Network.h"
+#include "common/nxdn/NXDNDefines.h"
+#include "common/nxdn/lc/RTCH.h"
+
+#include <catch2/catch_test_macros.hpp>
+#include <cstring>
+
+using namespace network;
+using namespace nxdn;
+using namespace nxdn::defines;
+
+// ---------------------------------------------------------------------------
+//  Class Declaration
+// ---------------------------------------------------------------------------
+
+/**
+ * @brief Test network class for NXDN frame serialization.
+ */
+class NXDNFrameTestNetwork final : public Network {
+public:
+    /**
+     * @brief Initializes a new instance of the NXDNFrameTestNetwork class.
+     */
+    NXDNFrameTestNetwork() :
+        Network("127.0.0.1", 1U, 0U, 1U, "test", true, false,
+            false, false, true, false, true, true, false, false, false, false)
+    {
+        /* stub */
+    }
+
+    /**
+     * @brief Creates an NXDN FNE message containing a single CAI frame.
+     * @param length The length of the created message.
+     * @param control The NXDN RTCH control information.
+     * @param frame The CAI frame data.
+     * @param frameLength The length of the CAI frame data.
+     * @returns UInt8Array The serialized NXDN FNE message.
+     */
+    UInt8Array create(uint32_t& length, const lc::RTCH& control,
+        const uint8_t* frame, uint32_t frameLength)
+    {
+        return createNXDN_Message(length, control, frame, frameLength);
+    }
+};
+
+TEST_CASE("NXDN FNE message carries exactly one CAI frame", "[nxdn][network]")
+{
+    NXDNFrameTestNetwork network;
+    lc::RTCH control;
+    control.setMessageType(MessageType::RTCH_VCALL);
+    control.setSrcId(1201U);
+    control.setDstId(2201U);
+
+    uint8_t frame[NXDN_FRAME_LENGTH_BYTES];
+    for (uint32_t i = 0U; i < sizeof(frame); i++)
+        frame[i] = (uint8_t)i;
+
+    uint32_t messageLength = 0U;
+    UInt8Array message = network.create(messageLength, control, frame, sizeof(frame));
+
+    REQUIRE(message != nullptr);
+    REQUIRE(messageLength == NXDN_PACKET_LENGTH + PACKET_PAD);
+    REQUIRE(::memcmp(message.get(), TAG_NXDN_DATA, 4U) == 0);
+    REQUIRE(message[23U] == NXDN_FRAME_LENGTH_BYTES);
+    REQUIRE(::memcmp(message.get() + MSG_HDR_SIZE, frame, sizeof(frame)) == 0);
+}