chore: import upstream snapshot with attribution

2026-07-13 13:27:18 +08:00
commit d72d1a58f0
553 changed files with 214565 additions and 0 deletions
@@ -0,0 +1,54 @@
+/*!
+ * Copyright (c) 2021-2026 Microsoft Corporation. All rights reserved.
+ * Copyright (c) 2021-2026 The LightGBM developers. All rights reserved.
+ * Licensed under the MIT License. See LICENSE file in the project root for license information.
+ */
+
+#include <gtest/gtest.h>
+#include <LightGBM/meta.h>
+#include <LightGBM/utils/array_args.h>
+
+#include <random>
+#include <vector>
+
+using LightGBM::data_size_t;
+using LightGBM::score_t;
+using LightGBM::ArrayArgs;
+
+
+TEST(Partition, JustWorks) {
+  std::vector<score_t> gradients({0.5f, 5.0f, 1.0f, 2.0f, 2.0f});
+  data_size_t middle_begin, middle_end;
+
+  ArrayArgs<score_t>::Partition(&gradients, 0, static_cast<int>(gradients.size()), &middle_begin, &middle_end);
+
+  EXPECT_EQ(gradients[middle_begin + 1], gradients[middle_end - 1]);
+  EXPECT_GT(gradients[0], gradients[middle_begin + 1]);
+  EXPECT_GT(gradients[middle_begin + 1], gradients.back());
+}
+
+TEST(Partition, PartitionOneElement) {
+  std::vector<score_t> gradients({0.5f});
+  data_size_t middle_begin, middle_end;
+  ArrayArgs<score_t>::Partition(&gradients, 0, static_cast<int>(gradients.size()), &middle_begin, &middle_end);
+  EXPECT_EQ(gradients[middle_begin + 1], gradients[middle_end - 1]);
+}
+
+TEST(Partition, Empty) {
+  std::vector<score_t> gradients;
+  data_size_t middle_begin, middle_end;
+  ArrayArgs<score_t>::Partition(&gradients, 0, static_cast<int>(gradients.size()), &middle_begin, &middle_end);
+
+  EXPECT_EQ(middle_begin, -1);
+  EXPECT_EQ(middle_end, 0);
+}
+
+TEST(Partition, AllEqual) {
+  std::vector<score_t> gradients({0.5f, 0.5f, 0.5f});
+  data_size_t middle_begin, middle_end;
+  ArrayArgs<score_t>::Partition(&gradients, 0, static_cast<int>(gradients.size()), &middle_begin, &middle_end);
+
+  EXPECT_EQ(gradients[middle_begin + 1], gradients[middle_end - 1]);
+  EXPECT_EQ(middle_begin, -1);
+  EXPECT_EQ(middle_end, 3);
+}