implement sort test

Makefile

@@ -29,7 +29,8 @@ TEST_SRC		= $(TEST_DIR)/test_check_args.cpp \
 					$(TEST_DIR)/test_push_stack.cpp \
 					$(TEST_DIR)/test_reverse_rotate_stack.cpp \
 					$(TEST_DIR)/test_rotate_stack.cpp \
-					$(TEST_DIR)/test_swap_stack.cpp
+					$(TEST_DIR)/test_swap_stack.cpp \
+					$(TEST_DIR)/test_sort.cpp
 TEST_OBJ		= $(filter-out $(BUILD_DIR)/main.o, $(patsubst $(SRC_DIR)/%.c, $(BUILD_DIR)/%.o, $(SRC)))
 GTEST_VERSION	= 1.14.0
 GTEST_DIR		= ./test/gtest

test/test_sort.cpp

@@ -0,0 +1,77 @@
+// Copyright 2024, reasuke
+
+#include <vector>
+#include <algorithm>
+#include <sstream>
+
+std::stringstream cout;
+
+#include "gtest/gtest.h"
+
+extern "C" {
+  #include "push_swap.h"
+}
+
+static void sort_test_main(int N) {
+  // initialize vector
+  // e.g. N = 3 -> v = {1, 2, 3}
+  std::vector<int> v(N);
+  for (int i = 0; i < N; ++i) {
+    v[i] = i + 1;
+  }
+
+  // generate permutation of v (N! patterns)
+  // e.g. N = 3, generate the below vectors (3! = 6 patterns)
+  // {1, 2, 3}
+  // {1, 3, 2}
+  // {2, 1, 3}
+  // {2, 3, 1}
+  // {3, 1, 2}
+  // {3, 2, 1}
+  do {
+    // initialize stack
+    t_list *stack_a = NULL;
+    t_list *stack_b = NULL;
+    for (int &i : v) {
+      ft_lstadd_back(&stack_a, ft_lstnew(new int(i)));
+    }
+    // sort
+    sort(&stack_a, &stack_b, N);
+    // check if the order is appropreate
+    for (int i = 1; stack_a; ++i, stack_a = stack_a->next) {
+      EXPECT_EQ(*(int *)stack_a->content, i);
+    }
+  } while (std::next_permutation(v.begin(), v.end()));
+}
+
+static void sort_test(int N) {
+  // save stdout
+  int stdout_copy = dup(STDOUT_FILENO);
+  // redirect stdout to /dev/null
+  int dev_null = open("/dev/null", O_WRONLY);
+  dup2(dev_null, 1);
+  close(dev_null);
+
+  // execute test
+  sort_test_main(N);
+
+  // revert stdout
+  dup2(stdout_copy, STDOUT_FILENO);
+  close(stdout_copy);
+}
+
+TEST(sort, oneElement) {
+  sort_test(1);
+}
+
+TEST(sort, twoElements) {
+  sort_test(2);
+}
+
+TEST(sort, threeEelments) {
+  sort_test(3);
+}
+
+TEST(sort, fourElements) {
+  sort_test(4);
+}