Function OnFileChanged

source/cpu.cpp:355–428

// ***********************************************************************

void OnFileChanged(FileChange change, void* pUserData) {
	// check for luau file changes
	for (int i=0; i<pState->luaFilesToWatch.count; i++) {
		if (pState->luaFilesToWatch[i] == change.path) {
			Log::Info("Luau file %s changed, reloading", change.path.pData);

			// when you reload a module
			// you will load it up onto the stack, and then look up it's existing 
			// and shallow copy the contents from the new to the old, then just drop the new one
			pState->frontend.markDirty(change.path.pData);
			if (!CompileAndLoadModule(change.path, 1)) {
				return;
			}
			lua_State* L = pState->pProgramState;
			
			// this will be the main.luau file, rather than a module, so no patching required
			if (lua_isnil(L, -1)) {
				if (pState->hasStarted == false) {
					pState->appLoaded = true;
					Start();
				}
				lua_pop(L, 1);
				return;
			}

			i32 newModuleIndex = lua_gettop(L);
			luaL_findtable(L, LUA_REGISTRYINDEX, "_MODULES", 1);
			lua_getfield(L, -1, change.path.pData);

			// shallow copy the new table into the existing one in the registry (which everyone points to)
			lua_pushnil(L);
			while(lua_next(L, newModuleIndex) != 0) {
				lua_pushvalue(L, -2);
				lua_insert(L, -2);
				lua_settable(L, -4);
			}
			lua_pop(L, 3);
		}
	}

	// check for asset changes
	for (int i=0; i<pState->assetsToWatch.count; i++) {
		if (pState->assetsToWatch[i] == change.path) {
			String extension = TakeAfterLastDot(change.path);
			if (extension == "gltf") {
				lua_State* L = pState->pProgramState;
				AssetImporter::ImportTableAsset& asset = pState->pImportTable->table[change.path];

				// reimport the asset, leaving it loaded into lua (i.e. we don't serialize it)
				if (AssetImporter::ImportGltf(g_pArenaFrame, L, asset.importFormat, change.path)) {
					// you want to lookup the asset in the ASSET table
					i32 newAssetIndex = lua_gettop(L);
					luaL_findtable(L, LUA_REGISTRYINDEX, "_ASSETS", 1);
					lua_getfield(L, -1, change.path.pData);

					// check to make sure the asset has not been deleted by gc
					if (lua_isnil(L, -1)) {
						lua_pop(L, 3);