Function startXcodeStateWatcher

src/utils/xcode-state-watcher.ts:189–246

(options: StartWatcherOptions = {})

 * Start watching the xcuserstate file for changes
 */
export async function startXcodeStateWatcher(options: StartWatcherOptions = {}): Promise<boolean> {
  if (state.watcher) {
    log('debug', '[xcode-watcher] Watcher already running');
    return true;
  }

  const executor = options.executor ?? getDefaultCommandExecutor();
  const cwd = options.cwd ?? process.cwd();

  const xcuserstatePath = await findXcodeStateFile({
    executor,
    cwd,
    searchRoot: options.searchRoot,
    workspacePath: options.workspacePath,
    projectPath: options.projectPath,
  });

  if (!xcuserstatePath) {
    log('debug', '[xcode-watcher] No xcuserstate file found, watcher not started');
    return false;
  }

  // Initialize cached state
  const initialState = extractState(xcuserstatePath);
  state.cachedScheme = initialState.scheme;
  state.cachedSimulatorId = initialState.simulatorId;
  state.watchedPath = xcuserstatePath;
  state.executor = executor;
  state.cwd = cwd;
  state.projectPath = options.projectPath ?? null;
  state.workspacePath = options.workspacePath ?? null;

  log(
    'info',
    `[xcode-watcher] Starting watcher for ${xcuserstatePath} (scheme="${initialState.scheme}", sim="${initialState.simulatorId}")`,
  );

  state.watcher = watch(xcuserstatePath, {
    persistent: true,
    ignoreInitial: true,
    awaitWriteFinish: {
      stabilityThreshold: 100,
      pollInterval: 50,
    },
  });

  state.watcher.on('change', () => {
    log('debug', '[xcode-watcher] File change detected');
    handleFileChange();
  });

  state.watcher.on('error', (error: unknown) => {
    const message = error instanceof Error ? error.message : String(error);
    log('warn', `[xcode-watcher] Watcher error: ${message}`);
  });

  return true;
}