verify successfull TM serialization

unittests/mocks/CdsShortTimestamperMock.h

@@ -0,0 +1,53 @@
+#ifndef FSFW_TESTS_CDSSHORTTIMESTAMPERMOCK_H
+#define FSFW_TESTS_CDSSHORTTIMESTAMPERMOCK_H
+
+#include <array>
+
+#include "fsfw/timemanager/TimeStamperIF.h"
+
+class CdsShortTimestamperMock : public TimeStamperIF {
+ public:
+  unsigned int serializeCallCount = 0;
+  ReturnValue_t lastSerializeResult = HasReturnvaluesIF::RETURN_OK;
+  unsigned int getSizeCallCount = 0;
+  std::array<uint8_t, 7> valueToStamp{};
+
+  CdsShortTimestamperMock() = default;
+
+  explicit CdsShortTimestamperMock(std::array<uint8_t, 7> valueToStamp)
+      : valueToStamp(valueToStamp) {}
+
+  ReturnValue_t serialize(uint8_t **buffer, size_t *size, size_t maxSize,
+                          Endianness streamEndianness) const override {
+    auto &thisNonConst = const_cast<CdsShortTimestamperMock &>(*this);
+    thisNonConst.serializeCallCount += 1;
+    if (*size + getSerializedSize() > maxSize) {
+      thisNonConst.lastSerializeResult = SerializeIF::BUFFER_TOO_SHORT;
+      return lastSerializeResult;
+    }
+    std::copy(valueToStamp.begin(), valueToStamp.end(), *buffer);
+    thisNonConst.lastSerializeResult = HasReturnvaluesIF::RETURN_OK;
+    *buffer += getSerializedSize();
+    *size += getSerializedSize();
+    return lastSerializeResult;
+  }
+  [[nodiscard]] size_t getSerializedSize() const override {
+    auto &thisNonConst = const_cast<CdsShortTimestamperMock &>(*this);
+    thisNonConst.getSizeCallCount += 1;
+    return valueToStamp.size();
+  }
+  ReturnValue_t deSerialize(const uint8_t **buffer, size_t *size,
+                            Endianness streamEndianness) override {
+    return HasReturnvaluesIF::RETURN_FAILED;
+  }
+  [[nodiscard]] size_t getTimestampSize() const override { return getSerializedSize(); }
+  ReturnValue_t addTimeStamp(uint8_t *buffer, uint8_t maxSize) override { return 0; }
+
+  void reset() {
+    serializeCallCount = 0;
+    getSizeCallCount = 0;
+  }
+
+ private:
+};
+#endif  // FSFW_TESTS_CDSSHORTTIMESTAMPERMOCK_H