Webpack의 Tapable

// https://webpack.js.org/contribute/writing-a-plugin/
class MyExampleWebpackPlugin {
  apply(compiler) {

    compiler.hooks.emit.tapAsync(
      'MyExampleWebpackPlugin',
      (compilation, callback) => {
        console.log('This is an example plugin!');

        callback();
      }
    );
  }
}