test: add malloc_byte_buffer / mutable_byte_buffer tests

CMakeLists.txt

@@ -485,6 +485,7 @@ if(WITH_TESTS)
       test/badfs_test.cpp
       test/block_merger_test.cpp
       test/block_range_test.cpp
+      test/byte_buffer_test.cpp
       test/checksum_test.cpp
       test/chmod_transformer_test.cpp
       test/entry_test.cpp

test/byte_buffer_test.cpp

@@ -0,0 +1,103 @@
+/* vim:set ts=2 sw=2 sts=2 et: */
+/**
+ * \author     Marcus Holland-Moritz (github@mhxnet.de)
+ * \copyright  Copyright (c) Marcus Holland-Moritz
+ *
+ * This file is part of dwarfs.
+ *
+ * dwarfs is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * dwarfs is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with dwarfs.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+
+#include <cstring>
+
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+
+#include <dwarfs/malloc_byte_buffer.h>
+#include <dwarfs/mapped_byte_buffer.h>
+
+TEST(byte_buffer_test, malloc_byte_buffer) {
+  auto buf = dwarfs::malloc_byte_buffer::create();
+  static_assert(std::same_as<decltype(buf), dwarfs::mutable_byte_buffer>);
+
+  EXPECT_TRUE(buf);
+  EXPECT_TRUE(buf.empty());
+
+  EXPECT_EQ(buf.size(), 0);
+  EXPECT_EQ(buf.capacity(), 0);
+  EXPECT_EQ(buf.data(), nullptr);
+
+  buf.reserve(20);
+  EXPECT_EQ(buf.capacity(), 20);
+
+  buf.resize(10);
+  EXPECT_EQ(buf.size(), 10);
+  EXPECT_EQ(buf.capacity(), 20);
+
+  buf.clear();
+  EXPECT_EQ(buf.size(), 0);
+  EXPECT_EQ(buf.capacity(), 20);
+
+  buf.append("Hello, World!", 13);
+  EXPECT_EQ(buf.size(), 13);
+  EXPECT_EQ(std::string_view(reinterpret_cast<char*>(buf.data()), buf.size()),
+            "Hello, World!");
+
+  buf.shrink_to_fit();
+  EXPECT_EQ(buf.size(), 13);
+  EXPECT_EQ(buf.capacity(), 13);
+
+  buf.freeze_location();
+
+  EXPECT_THAT([&] { buf.reserve(30); },
+              ::testing::ThrowsMessage<std::runtime_error>(
+                  "operation not allowed on frozen buffer: reserve"));
+
+  EXPECT_THAT(
+      [&] { buf.resize(20); },
+      ::testing::ThrowsMessage<std::runtime_error>(
+          "operation not allowed on frozen buffer: resize beyond capacity"));
+
+  EXPECT_NO_THROW(buf.resize(5));
+  EXPECT_EQ(buf.size(), 5);
+  EXPECT_NO_THROW(buf.append("!", 1));
+
+  EXPECT_THAT(
+      [&] { buf.append("Too much!", 9); },
+      ::testing::ThrowsMessage<std::runtime_error>(
+          "operation not allowed on frozen buffer: append beyond capacity"));
+
+  EXPECT_THAT([&] { buf.clear(); },
+              ::testing::ThrowsMessage<std::runtime_error>(
+                  "operation not allowed on frozen buffer: clear"));
+
+  EXPECT_THAT([&] { buf.shrink_to_fit(); },
+              ::testing::ThrowsMessage<std::runtime_error>(
+                  "operation not allowed on frozen buffer: shrink_to_fit"));
+
+  auto buf2 = dwarfs::malloc_byte_buffer::create(buf.span());
+  EXPECT_TRUE(buf2);
+  EXPECT_FALSE(buf2.empty());
+  EXPECT_EQ(buf2.size(), 6);
+  EXPECT_NO_THROW(buf2.resize(30));
+  EXPECT_TRUE(std::memcmp(buf.data(), buf2.data(), 6) == 0);
+
+  buf = dwarfs::malloc_byte_buffer::create(13);
+
+  EXPECT_TRUE(buf);
+  EXPECT_FALSE(buf.empty());
+  EXPECT_EQ(buf.size(), 13);
+}