TST: Add tests for the new cuh2 utilities

CppCore/meson.build

@@ -52,6 +52,7 @@ if get_option('with_tests')
   test_args += ['-DPOTTEST']
   test_array = [#
     ['CuH2test', 'cuh2_test', 'CuH2PotTest.cc', ''],
+    ['CuH2 Utils Test', 'cuh2_util_test', 'cuh2UtilsTest.cc', ''],
   ]
   foreach test : test_array
     test(test.get(0),

CppCore/tests/cuh2UtilsTest.cc

@@ -0,0 +1,90 @@
+// MIT License
+// Copyright 2023--present Rohit Goswami <HaoZeke>
+#include <catch2/catch_all.hpp>
+
+#include "rgpot/CuH2/cuh2Utils.hpp"
+
+TEST_CASE("extract_positions correctly extracts position vectors",
+          "[extract_positions]") {
+  yodecon::types::ConFrameVec conFrameVec;
+  conFrameVec.prebox_header = {"Generated by eOn", ""};
+  conFrameVec.boxl = {25.0, 25.0, 25.0};
+  conFrameVec.angles = {90.0, 90.0, 90.0};
+  conFrameVec.postbox_header = {"", ""};
+  conFrameVec.natm_types = 4;
+  conFrameVec.natms_per_type = {2, 4, 6, 1};
+  conFrameVec.masses_per_type = {15.99, 12.011, 1.008, 32.065};
+  conFrameVec.symbol.push_back("O");
+  conFrameVec.x.push_back(10.477713);
+  conFrameVec.y.push_back(12.379463);
+  conFrameVec.z.push_back(12.871778);
+  conFrameVec.is_fixed.push_back(false);
+  conFrameVec.atom_id.push_back(1);
+  auto positions = rgpot::cuh2::utils::xts::extract_positions(conFrameVec);
+
+  REQUIRE(positions.shape()[0] == 1); // 1 atoms
+  REQUIRE(positions.shape()[1] == 3); // 3 dimensions
+
+  REQUIRE(positions(0, 0) == 10.477713);
+  REQUIRE(positions(0, 1) == 12.379463);
+  REQUIRE(positions(0, 2) == 12.871778);
+}
+
+TEST_CASE("perturb_positions correctly perturbs hydrogen atom positions and "
+          "sets new z-coordinate",
+          "[perturb_positions]") {
+  xt::xtensor<double, 2> base_positions = {{0, 0, 0}, {1, 0, 0}, {0.5, 0.5, 2}};
+  xt::xtensor<int, 1> atmNumVec = {1, 1, 29}; // Hydrogens and one Copper
+  double hcu_dist = 1.5;
+  double hh_dist = 1.0;
+
+  auto perturbed_positions = rgpot::cuh2::utils::xts::perturb_positions(
+      base_positions, atmNumVec, hcu_dist, hh_dist);
+
+  // Expected behavior
+  REQUIRE_THAT(perturbed_positions(0, 2),
+               Catch::Matchers::WithinAbs(2.0 + hcu_dist, 1e-4));
+  REQUIRE_THAT(perturbed_positions(1, 2),
+               Catch::Matchers::WithinAbs(2.0 + hcu_dist, 1e-4));
+
+  // Check if the distance between hydrogens is approximately 1.0
+  auto hDist = xt::linalg::norm(xt::row(perturbed_positions, 0) -
+                                xt::row(perturbed_positions, 1));
+  REQUIRE_THAT(hDist, Catch::Matchers::WithinAbs(hh_dist, 1e-4));
+}
+
+TEST_CASE("calculateDistances calculates distances correctly",
+          "[calculateDistances]") {
+  xt::xtensor<double, 2> positions = {
+      {0.0, 0.0, 3.0}, {1.0, 0.0, 3.0}, {0.5, 0.5, 2.0}};
+  xt::xtensor<int, 1> atmNumVec = {1, 1, 29}; // Hydrogens and one Copper
+
+  auto distances =
+      rgpot::cuh2::utils::xts::calculateDistances(positions, atmNumVec);
+  // Distance between hydrogens
+  REQUIRE_THAT(distances.first, Catch::Matchers::WithinAbs(1.0, 1e-4));
+  // Distance from H to top Cu layer
+  REQUIRE_THAT(distances.second, Catch::Matchers::WithinAbs(1.0, 1e-4));
+}
+
+// Additional tests to cover error handling and unexpected inputs
+TEST_CASE("perturb_positions throws when unexpected atom numbers arepresent",
+          "[perturb_positions]") {
+  xt::xtensor<double, 2> base_positions = {{0, 0, 0}, {1, 0, 0}};
+  xt::xtensor<int, 1> atmNumVec = {1, 30}; // Invalid atom number
+
+  REQUIRE_THROWS_AS(rgpot::cuh2::utils::xts::perturb_positions(
+                        base_positions, atmNumVec, 1.5, 1.0),
+                    std::runtime_error);
+}
+
+TEST_CASE(
+    "calculateDistances throws when not exactly two hydrogens are present",
+    "[calculateDistances]") {
+  xt::xtensor<double, 2> positions = {{0.0, 0.0, 3.0}, {0.5, 0.5, 2.0}};
+  xt::xtensor<int, 1> atmNumVec = {1, 29}; // Not two Hydrogens
+
+  REQUIRE_THROWS_AS(
+      rgpot::cuh2::utils::xts::calculateDistances(positions, atmNumVec),
+      std::runtime_error);
+}