prefix: align dependency setup and VFS fixes

2 files changed, 93 insertions, 1 deletions

diff --git a/src/tests/CMakeLists.txt b/src/tests/CMakeLists.txt
index 8e71366..24c4597 100644
--- a/src/tests/CMakeLists.txt
+++ b/src/tests/CMakeLists.txt
@@ -48,6 +48,27 @@ target_link_libraries(test_external_dir_mapping PRIVATE
 )
 add_test(NAME test_external_dir_mapping COMMAND test_external_dir_mapping)
 
+# ---------------------------------------------------------------------------
+# Overwrite duplicate scan tests
+# ---------------------------------------------------------------------------
+add_executable(test_overwrite_duplicates EXCLUDE_FROM_ALL
+    test_overwrite_duplicates.cpp
+    ${CMAKE_SOURCE_DIR}/src/src/vfs/trackedwrites.cpp
+)
+set_target_properties(test_overwrite_duplicates PROPERTIES
+    AUTOMOC OFF
+    CXX_STANDARD 23
+    CXX_STANDARD_REQUIRED ON
+)
+target_include_directories(test_overwrite_duplicates PRIVATE
+    ${CMAKE_SOURCE_DIR}/src/src
+)
+target_link_libraries(test_overwrite_duplicates PRIVATE
+    GTest::gtest
+    GTest::gtest_main
+)
+add_test(NAME test_overwrite_duplicates COMMAND test_overwrite_duplicates)
+
 # Register a "fluorine-tests" umbrella target that builds every test exe.
 add_custom_target(fluorine-tests
-    DEPENDS test_metainiutils test_external_dir_mapping)
+    DEPENDS test_metainiutils test_external_dir_mapping test_overwrite_duplicates)
diff --git a/src/tests/test_overwrite_duplicates.cpp b/src/tests/test_overwrite_duplicates.cpp
new file mode 100644
index 0000000..8cbf3ec
--- /dev/null
+++ b/src/tests/test_overwrite_duplicates.cpp
@@ -0,0 +1,71 @@
+#include "vfs/trackedwrites.h"
+
+#include <strings.h>
+
+#include <gtest/gtest.h>
+
+#include <algorithm>
+#include <filesystem>
+#include <fstream>
+
+namespace fs = std::filesystem;
+
+namespace
+{
+
+void writeText(const fs::path& path, const std::string& text)
+{
+  fs::create_directories(path.parent_path());
+  std::ofstream out(path, std::ios::binary | std::ios::trunc);
+  ASSERT_TRUE(out.is_open());
+  out << text;
+}
+
+}  // namespace
+
+TEST(OverwriteDuplicates, DetectsIdenticalAndDifferentMatches)
+{
+  const fs::path base = fs::temp_directory_path() / "fluorine_overwrite_dup_test";
+  fs::remove_all(base);
+
+  const fs::path overwrite = base / "overwrite";
+  const fs::path modA      = base / "ModA";
+  const fs::path modB      = base / "ModB";
+
+  writeText(overwrite / "SKSE/Plugins/Identical.ini", "same\n");
+  writeText(overwrite / "SKSE/Plugins/Different.ini", "overwrite\n");
+  writeText(overwrite / "SKSE/Plugins/OnlyOverwrite.ini", "only overwrite\n");
+
+  writeText(modA / "SKSE/Plugins/Identical.ini", "same\n");
+  writeText(modA / "SKSE/Plugins/Different.ini", "mod a\n");
+  writeText(modB / "SKSE/Plugins/Different.ini", "mod b wins\n");
+
+  TrackedWrites tracker;
+  const std::vector<std::pair<std::string, std::string>> mods = {
+      {"ModA", modA.string()},
+      {"ModB", modB.string()},
+  };
+
+  const auto duplicates = tracker.scanOverwriteDuplicates(overwrite.string(), mods);
+  ASSERT_EQ(duplicates.size(), 2u);
+
+  const auto identical = std::find_if(
+      duplicates.begin(), duplicates.end(),
+      [](const TrackedWrites::DuplicateEntry& entry) {
+        return entry.relative_path == "SKSE/Plugins/Identical.ini";
+      });
+  ASSERT_NE(identical, duplicates.end());
+  EXPECT_EQ(identical->mod_name, "ModA");
+  EXPECT_EQ(identical->state, TrackedWrites::DuplicateState::Identical);
+
+  const auto different = std::find_if(
+      duplicates.begin(), duplicates.end(),
+      [](const TrackedWrites::DuplicateEntry& entry) {
+        return entry.relative_path == "SKSE/Plugins/Different.ini";
+      });
+  ASSERT_NE(different, duplicates.end());
+  EXPECT_EQ(different->mod_name, "ModB");
+  EXPECT_EQ(different->state, TrackedWrites::DuplicateState::Different);
+
+  fs::remove_all(base);
+}