Add basic test for Spikegen functions

unit_tests/data/Test_Spikegen.cpp

+/********************************************************************************
+ * Copyright (c) 2025 CEA-List
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ ********************************************************************************/
+
+#include <cstdint>     // std::uint8_t, std::uint16_t, std::int32_t
+#include <vector>      // std::vector
+
+#include <catch2/catch_test_macros.hpp>
+
+#include "aidge/data/Spikegen.hpp"
+#include "aidge/data/Tensor.hpp"
+#include "aidge/utils/ArrayHelpers.hpp"
+#include "aidge/utils/TensorUtils.hpp"
+
+
+namespace Aidge
+{
+TEST_CASE("[core/data] SpikeGen zeros", "[SpikeGen]") {
+    auto input = Tensor(Array1D<float, 3>({0,0,0}));
+    auto expectedOutput = Tensor(Array2D<float, 3, 3>({{{0,0,0}, {0,0,0}, {0,0,0}}}));
+
+    auto spikes = spikegenRate(std::make_shared<Tensor>(input), 3);
+
+    approxEq<float>(spikes, expectedOutput);
+}
+
+TEST_CASE("[core/data] SpikeGen ones", "[SpikeGen]") {
+    auto input = Tensor(Array1D<float, 3>({1,1,1}));
+    auto expectedOutput = Tensor(Array2D<float, 3, 3>({{{1,1,1}, {1,1,1}, {1,1,1}}}));
+
+    auto spikes = spikegenRate(std::make_shared<Tensor>(input), 3);
+
+    approxEq<float>(spikes, expectedOutput);
+}
+}  // namespace Aidge