Run Command After Webpack Build

When working on a web development project, you might find yourself needing to run a specific command every time Webpack finishes building your project. This could be anything from deploying your application to triggering another process that relies on the freshly built files. In this article, we'll walk through how you can easily achieve this by running a command automatically after a Webpack build.

To accomplish this task, we'll be leveraging Webpack's built-in hooks that allow us to execute custom scripts at different points in the build process. Specifically, we'll make use of the `afterEmit` hook, which fires after Webpack has emitted assets.

First, let's create a simple Node.js script that we want to run after the Webpack build process. This script can be anything you need, such as deploying your files to a server or running tests on the built code. For this example, let's say we want to log a message to the console after the build completes.

// afterBuild.js
console.log("Webpack build completed successfully!");

Next, we need to modify our Webpack configuration to execute this script after the build finishes. Inside your webpack configuration file (usually named `webpack.config.js`), we'll add the following code snippet:

// webpack.config.js

const webpack = require('webpack');
const path = require('path');
const fs = require('fs');

module.exports = {
  entry: './src/index.js',
  output: {
    path: path.resolve(__dirname, 'dist'),
    filename: 'bundle.js',
  },
  plugins: [
    new webpack.DefinePlugin({
      process: {
        afterEmit: (compilation, callback) => {
          fs.readFile(path.resolve(__dirname, 'afterBuild.js'), 'utf-8', (err, data) => {
            if (!err) {
              eval(data);
            }
            callback();
          });
        },
      },
    }),
  ],
};

In this modified Webpack configuration, we use the `DefinePlugin` to introduce a custom `process.afterEmit` function that reads our `afterBuild.js` script file and executes its content using `eval()` after the build process is complete.

Now, when you run Webpack to build your project, the `afterBuild.js` script will be automatically executed, and you will see the specified message in the console.

Remember to adjust the `afterBuild.js` script to suit your specific needs, such as adding deployment commands or other post-build tasks. This simple technique can save you time and streamline your development workflow by automating repetitive tasks that follow the Webpack build process.

By incorporating custom scripts into your Webpack build process, you can enhance your web development workflow and ensure that your project remains efficient and up-to-date with just a little extra automation effort.