Function watchFile

packages/language-service/test/legacy/mock_host.ts:126–128

(path: string, callback: ts.FileWatcherCallback)

      return configFileFs.readFile(absPath, encoding);
    },
    watchFile(path: string, callback: ts.FileWatcherCallback): ts.FileWatcher {
      return configFileFs.watchFile(path, callback);
    },
    watchDirectory(path: string, callback: ts.DirectoryWatcherCallback): ts.FileWatcher {
      return NOOP_FILE_WATCHER;
    },