Method cb

packages/plugin/webpack/src/WebpackPlugin.ts:640–667

(err, stats)

      const compiler = webpack(mainConfig);
      const [onceResolve, onceReject] = once(resolve, reject);
      const cb: WebpackWatchHandler = async (err, stats) => {
        if (tab && stats) {
          tab.log(
            stats.toString({
              colors: true,
            }),
          );
        }
        if (this.config.jsonStats) {
          await this.writeJSONStats(
            'main',
            stats,
            mainConfig.stats as WebpackToJsonOptions,
            'main',
          );
        }

        if (err) return onceReject(err);
        if (!watch && stats?.hasErrors()) {
          return onceReject(
            new Error(
              `Compilation errors in the main process: ${stats.toString()}`,
            ),
          );
        }

        return onceResolve(undefined);
      };
      if (watch) {
        const watcher = compiler.watch({}, cb);
        if (watcher) {