Move dependencies in 'external' directory and pdate git submodules

external/Catch2/tests/SelfTest/IntrospectiveTests/Sharding.tests.cpp

@@ -0,0 +1,45 @@
+
+//              Copyright Catch2 Authors
+// Distributed under the Boost Software License, Version 1.0.
+//   (See accompanying file LICENSE.txt or copy at
+//        https://www.boost.org/LICENSE_1_0.txt)
+
+// SPDX-License-Identifier: BSL-1.0
+
+#include <catch2/catch_test_macros.hpp>
+#include <catch2/generators/catch_generators_all.hpp>
+
+#include <catch2/internal/catch_sharding.hpp>
+
+#include <unordered_map>
+#include <vector>
+
+TEST_CASE("Sharding Function", "[approvals]") {
+    std::vector<int> testContainer = { 0, 1, 2, 3, 4, 5, 6 };
+    std::unordered_map<int, std::vector<std::size_t>> expectedShardSizes = {
+        {1, {7}},
+        {2, {4, 3}},
+        {3, {3, 2, 2}},
+        {4, {2, 2, 2, 1}},
+        {5, {2, 2, 1, 1, 1}},
+        {6, {2, 1, 1, 1, 1, 1}},
+        {7, {1, 1, 1, 1, 1, 1, 1}},
+    };
+
+    auto shardCount = GENERATE(range(1, 7));
+    auto shardIndex = GENERATE_COPY(filter([=](int i) { return i < shardCount; }, range(0, 6)));
+
+    std::vector<int> result = Catch::createShard(testContainer, shardCount, shardIndex);
+
+    auto& sizes = expectedShardSizes[shardCount];
+    REQUIRE(result.size() == sizes[shardIndex]);
+
+    std::size_t startIndex = 0;
+    for(int i = 0; i < shardIndex; i++) {
+        startIndex += sizes[i];
+    }
+
+    for(std::size_t i = 0; i < sizes[shardIndex]; i++) {
+        CHECK(result[i] == testContainer[i + startIndex]);
+    }
+}