test(tests/eos): added eos tests

tests/eos/eosTest.cpp

@@ -0,0 +1,70 @@
+#include <gtest/gtest.h>
+#include <iostream>
+#include <string>
+#include <vector>
+#include <set>
+#include <sstream>
+
+#include "helm.h"
+
+/**
+ * @file constTest.cpp
+ * @brief Unit tests for the const class.
+ */
+
+/**
+ * @brief Test suite for the const class.
+ */
+class eosTest : public ::testing::Test {};
+
+std::string HELM_FILENAME = std::string(getenv("MESON_SOURCE_ROOT")) + "/assets/eos/helm_table.dat";
+/**
+ * @test Verify default constructor initializes correctly.
+ */
+TEST_F(eosTest, constructor) {
+    using namespace helmholtz;
+    EXPECT_NO_THROW(HELMTable table = read_helm_table(HELM_FILENAME));
+}
+
+TEST_F(eosTest, read_helm_table) {
+    using namespace helmholtz;
+    HELMTable table = read_helm_table(HELM_FILENAME);
+    // Capture the << operator output as a string
+    std::stringstream ss;
+    ss << table;
+    EXPECT_EQ(ss.str(), "HELMTable Data:\n  imax: 541, jmax: 201\n  Temperature Range: [1000, 1e+13]\n  Density Range: [1e-12, 1e+15]\n");
+}
+
+TEST_F(eosTest, get_helm_EOS) {
+    using namespace helmholtz;
+
+    const int nel=3;
+    double xmass[nel], aion[nel], zion[nel];
+    EOSInput eos1;
+
+    xmass[0] = 0.75; aion[0] =  1.0; zion[0] = 1.0;
+    xmass[1] = 0.23; aion[1] =  4.0; zion[1] = 2.0; 
+    xmass[2] = 0.02; aion[2] = 12.0; zion[2] = 6.0;
+
+    eos1.T = 1.0e8;
+    eos1.rho = 1.0e6;
+
+    double asum = 0.0;
+    double zsum = 0.0;
+    for (int i=0; i<nel; i++) {
+        asum += xmass[i]/aion[i];
+        zsum += xmass[i]*zion[i]/aion[i];
+    }
+    eos1.abar = 1.0/asum;
+    eos1.zbar = eos1.abar*zsum;
+
+    HELMTable table = read_helm_table(HELM_FILENAME);
+    EOS eos = get_helm_EOS(eos1, table);
+    // std::cout << eos << std::endl;
+
+    EXPECT_DOUBLE_EQ(eos.ye, 0.875);
+    EXPECT_DOUBLE_EQ(eos.etaele, 23.04334823102155);
+    // TODO: Add more tests for more values
+}
+
+