Add unit tests for the cd command

test/cd.cpp

@@ -0,0 +1,57 @@
+#include "../src/FileSystem/FileSystem.hpp"
+#include <filesystem>
+#include <gtest/gtest.h>
+
+class CdTest : public testing::Test {
+protected:
+  // NOLINTBEGIN(cppcoreguidelines-non-private-member-variables-in-classes)
+  std::string const PATH = "test.fs";
+  std::uint64_t const SIZE = 1024;
+  std::uint64_t const CLUSTER_SIZE = 64;
+
+  FileSystem file_system_;
+  // NOLINTEND(cppcoreguidelines-non-private-member-variables-in-classes)
+
+  auto SetUp() -> void override {
+    FileSystem::make(PATH, {SIZE, CLUSTER_SIZE});
+    file_system_ = FileSystem(PATH);
+  }
+
+  auto TearDown() -> void override { std::filesystem::remove(PATH); }
+};
+
+TEST_F(CdTest, Empty) {
+  file_system_.mkdir("/dir1");
+  file_system_.mkdir("/dir2");
+  file_system_.mkdir("/dir3");
+
+  file_system_.cd("/dir1");
+  EXPECT_EQ(file_system_.pwd(), "/dir1");
+  file_system_.cd("/dir2");
+  EXPECT_EQ(file_system_.pwd(), "/dir2");
+  file_system_.cd("/dir3");
+  EXPECT_EQ(file_system_.pwd(), "/dir3");
+}
+
+TEST_F(CdTest, NonExistent) { EXPECT_THROW(file_system_.cd("/non_existent"), std::invalid_argument); }
+
+TEST_F(CdTest, NonExistentNested) {
+  file_system_.mkdir("/dir1");
+  file_system_.mkdir("/dir2");
+  file_system_.mkdir("/dir1/dir3");
+
+  EXPECT_THROW(file_system_.cd("/dir1/non_existent"), std::invalid_argument);
+}
+
+TEST_F(CdTest, MultipleFilesNested) {
+  file_system_.mkdir("dir1");
+  file_system_.mkdir("dir2");
+  file_system_.mkdir("dir1/dir3");
+
+  file_system_.cd("dir1");
+  EXPECT_EQ(file_system_.pwd(), "/dir1");
+  file_system_.cd("dir3");
+  EXPECT_EQ(file_system_.pwd(), "/dir1/dir3");
+  file_system_.cd("/dir2");
+  EXPECT_EQ(file_system_.pwd(), "/dir2");
+}