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

test/ObjCommonTestUtils/SearchPath/MockOutputPath.cpp

@@ -0,0 +1,49 @@
+#include "MockOutputPath.h"
+
+#include <sstream>
+
+namespace
+{
+    class MockFileWrapper final : public std::ostringstream
+    {
+    public:
+        MockFileWrapper(std::string name, std::vector<MockOutputFile>& files)
+            : m_name(std::move(name)),
+              m_files(files)
+        {
+        }
+
+        ~MockFileWrapper() override
+        {
+            m_files.emplace_back(std::move(m_name), str());
+        }
+
+    private:
+        std::string m_name;
+        std::vector<MockOutputFile>& m_files;
+    };
+} // namespace
+
+MockOutputFile::MockOutputFile() = default;
+
+MockOutputFile::MockOutputFile(std::string name, std::string data)
+    : m_name(std::move(name)),
+      m_data(std::move(data))
+{
+}
+
+std::unique_ptr<std::ostream> MockOutputPath::Open(const std::string& fileName)
+{
+    return std::make_unique<MockFileWrapper>(fileName, m_files);
+}
+
+const MockOutputFile* MockOutputPath::GetMockedFile(const std::string& name) const
+{
+    for (const auto& file : m_files)
+    {
+        if (file.m_name == name)
+            return &file;
+    }
+
+    return nullptr;
+}