chore: add abstraction for opening output files to be able to mock it

src/ObjCommon/SearchPath/IOutputPath.h

@@ -0,0 +1,18 @@
+#pragma once
+
+#include <memory>
+#include <ostream>
+#include <string>
+
+class IOutputPath
+{
+public:
+    IOutputPath() = default;
+    virtual ~IOutputPath() = default;
+    IOutputPath(const IOutputPath& other) = default;
+    IOutputPath(IOutputPath&& other) noexcept = default;
+    IOutputPath& operator=(const IOutputPath& other) = default;
+    IOutputPath& operator=(IOutputPath&& other) noexcept = default;
+
+    virtual std::unique_ptr<std::ostream> Open(const std::string& fileName) = 0;
+};

src/ObjCommon/SearchPath/OutputPathFilesystem.cpp

@@ -0,0 +1,27 @@
+#include "OutputPathFilesystem.h"
+
+#include <fstream>
+
+namespace fs = std::filesystem;
+
+OutputPathFilesystem::OutputPathFilesystem(const fs::path& path)
+    : m_path(fs::canonical(path))
+{
+}
+
+std::unique_ptr<std::ostream> OutputPathFilesystem::Open(const std::string& fileName)
+{
+    const auto fullNewPath = fs::canonical(m_path / fileName);
+
+    if (!fullNewPath.string().starts_with(m_path.string()))
+        return nullptr;
+
+    const auto containingDirectory = fullNewPath.parent_path();
+    fs::create_directories(containingDirectory);
+
+    std::ofstream stream(fullNewPath, std::ios::binary | std::ios::out);
+    if (!stream.is_open())
+        return nullptr;
+
+    return std::make_unique<std::ofstream>(std::move(stream));
+}

src/ObjCommon/SearchPath/OutputPathFilesystem.h

@@ -0,0 +1,16 @@
+#pragma once
+
+#include "IOutputPath.h"
+
+#include <filesystem>
+
+class OutputPathFilesystem final : public IOutputPath
+{
+public:
+    explicit OutputPathFilesystem(const std::filesystem::path& path);
+
+    std::unique_ptr<std::ostream> Open(const std::string& fileName) override;
+
+private:
+    std::filesystem::path m_path;
+};