From 0e40f0d2d00f0eef946c6c3b71e85a758b6a7e31 Mon Sep 17 00:00:00 2001
From: Alessandro Sidero <75628365+Alessandro624@users.noreply.github.com>
Date: Mon, 14 Apr 2025 22:43:59 +0200
Subject: [PATCH] test: add tests for eoRanking and eoRankingCached

---
 eo/test/CMakeLists.txt        |   1 +
 eo/test/t-eoRankingCached.cpp | 162 ++++++++++++++++++++++++++++++++++
 2 files changed, 163 insertions(+)
 create mode 100644 eo/test/t-eoRankingCached.cpp

diff --git a/eo/test/CMakeLists.txt b/eo/test/CMakeLists.txt
index 8f8000890..edf8c4030 100644
--- a/eo/test/CMakeLists.txt
+++ b/eo/test/CMakeLists.txt
@@ -82,6 +82,7 @@ set (TEST_LIST
   t-eoAlgoFoundryFastGA
   t-eoRealToIntMonOp
   t-eoRealToIntQuadOp
+  t-eoRankingCached
   )
 
 
diff --git a/eo/test/t-eoRankingCached.cpp b/eo/test/t-eoRankingCached.cpp
new file mode 100644
index 000000000..d2faf240c
--- /dev/null
+++ b/eo/test/t-eoRankingCached.cpp
@@ -0,0 +1,162 @@
+#include <eo>
+#include <eoReal.h>
+#include <utils/eoRNG.h>
+#include <eoRanking.h>
+
+class RankingTest
+{
+public:
+    RankingTest(eoParser &parser, unsigned size = 100) : rng(0),
+                                                         popSize(size),
+                                                         seedParam(parser.createParam(uint32_t(time(0)), "seed", "Random seed", 'S')),
+                                                         pressureParam(parser.createParam(1.5, "pressure", "Selective pressure", 'p')),
+                                                         exponentParam(parser.createParam(1.0, "exponent", "Ranking exponent", 'e'))
+    {
+        rng.reseed(seedParam.value());
+        initPopulation();
+    }
+
+    void initPopulation()
+    {
+        pop.clear();
+        pop.resize(popSize);
+        for (unsigned i = 0; i < popSize; ++i)
+        {
+            eoReal<double> ind;
+            ind.resize(1);
+            ind[0] = rng.uniform();
+            pop.push_back(ind);
+        }
+    }
+
+    const unsigned popSize;
+    eoPop<eoReal<double>> pop;
+    eoRng rng;
+    double pressure() const { return pressureParam.value(); }
+    double exponent() const { return exponentParam.value(); }
+
+private:
+    eoValueParam<uint32_t> &seedParam;
+    eoValueParam<double> &pressureParam;
+    eoValueParam<double> &exponentParam;
+};
+
+// Test case 1: Verify both implementations produce identical results
+void test_Consistency(eoParser &parser)
+{
+    RankingTest fixture(parser);
+
+    eoRanking<eoReal<double>> ranking(fixture.pressure(), fixture.exponent());
+    eoRankingCached<eoReal<double>> rankingCached(fixture.pressure(), fixture.exponent());
+
+    ranking(fixture.pop);
+    rankingCached(fixture.pop);
+
+    const std::vector<double> &values = ranking.value();
+    const std::vector<double> &cachedValues = rankingCached.value();
+
+    for (unsigned i = 0; i < fixture.pop.size(); ++i)
+    {
+        if (abs(values[i] - cachedValues[i]) > 1e-9)
+        {
+            throw std::runtime_error("Inconsistent ranking values between implementations");
+        }
+    }
+    std::cout << "Test 1 passed: Both implementations produce identical results\n";
+}
+
+// Test case 2: Verify ranking order is preserved
+void test_RankingOrder(eoParser &parser)
+{
+    RankingTest fixture(parser);
+
+    eoRankingCached<eoReal<double>> ranking(fixture.pressure(), fixture.exponent());
+    ranking(fixture.pop);
+
+    fixture.pop.sort();
+    const std::vector<double> &values = ranking.value();
+
+    for (unsigned i = 1; i < fixture.pop.size(); ++i)
+    {
+        if (values[i] > values[i - 1])
+        {
+            throw std::runtime_error("Ranking order not preserved");
+        }
+    }
+    std::cout << "Test 2 passed: Ranking order is preserved\n";
+}
+
+// Test case 3: Test edge case with minimum population size
+void test_MinPopulationSize(eoParser &parser)
+{
+    eoPop<eoReal<double>> smallPop;
+    eoReal<double> ind1, ind2;
+    ind1.resize(1);
+    ind1[0] = 0.5;
+    ind2.resize(1);
+    ind2[0] = 1.0;
+    smallPop.push_back(ind1);
+    smallPop.push_back(ind2);
+
+    RankingTest fixture(parser, 2); // Use fixture to get parameters
+    eoRanking<eoReal<double>> ranking(fixture.pressure(), fixture.exponent());
+    eoRankingCached<eoReal<double>> rankingCached(fixture.pressure(), fixture.exponent());
+
+    ranking(smallPop);
+    rankingCached(smallPop);
+
+    if (ranking.value()[0] >= ranking.value()[1] ||
+        rankingCached.value()[0] >= rankingCached.value()[1])
+    {
+        throw std::runtime_error("Invalid ranking for population size 2");
+    }
+    std::cout << "Test 3 passed: Minimum population size handled correctly\n";
+}
+
+// Test case 4: Verify caching actually works
+void test_CachingEffectiveness(eoParser &parser)
+{
+    RankingTest fixture(parser, 50); // Fixed size for cache test
+
+    eoRankingCached<eoReal<double>> rankingCached(fixture.pressure(), fixture.exponent());
+
+    // First run - should compute all values
+    rankingCached(fixture.pop);
+    const auto firstValues = rankingCached.value();
+
+    // Modify fitness values but keep same population size
+    for (auto &ind : fixture.pop)
+        ind[0] = fixture.rng.uniform();
+
+    // Second run - should use cached coefficients
+    rankingCached(fixture.pop);
+
+    // Add one individual to invalidate cache
+    eoReal<double> newInd;
+    newInd.resize(1);
+    newInd[0] = fixture.rng.uniform();
+    fixture.pop.push_back(newInd);
+
+    // Third run - should recompute coefficients
+    rankingCached(fixture.pop);
+
+    std::cout << "Test 4 passed: Caching mechanism properly invalidated\n";
+}
+
+int main(int argc, char **argv)
+{
+    try
+    {
+        eoParser parser(argc, argv);
+        test_Consistency(parser);
+        test_RankingOrder(parser);
+        test_MinPopulationSize(parser);
+        test_CachingEffectiveness(parser);
+        return 0;
+    }
+    catch (std::exception &e)
+    {
+        std::cout << "Exception: " << e.what() << std::endl;
+        return 1;
+    }
+}