Introduction

Next.js is a popular framework for building React applications, offering features like server-side rendering and efficient code splitting. In the development process, Next.js provides a convenient hot reload feature, allowing developers to see instant changes without manual refreshes. This article introduces how to run a command during hot reload in a Next.js application.

Next.js Configuration

To run a command during hot reload in a Next.js application, you need to configure the Next.js project using the next.config.js file. This file serves as the central configuration point for your Next.js application and allows you to define custom logic during the development server's startup and restart phases.

Here's a step-by-step guide on setting up the Next.js configuration:

1. Create a file named next.config.js in the root directory of your Next.js project if it doesn't already exist.
2. Open the next.config.js file in your preferred code editor.
3. Inside the file, export a configuration object by assigning it to module.exports:

module.exports = {
  // Configuration options will be added here
};

4. Next, add the webpackDevMiddleware property to the configuration object. This property allows you to define custom logic during the development server's startup and restart phases:

module.exports = {
  webpackDevMiddleware: (config) => {
    // Custom logic will be added here
    return config;
  },
};

5. Within the webpackDevMiddleware function, you can add your custom logic, including the execution of a command. For executing the command, you can use the child_process module or any other method of your choice. Here's an example using the child_process.exec method:

const { exec } = require('child_process');

module.exports = {
  webpackDevMiddleware: (config) => {
    exec('<Your command>', (error, stdout, stderr) => {
      if (error) {
        console.error(`Error executing script: ${error}`);
        return;
      }
      console.log(`Script output: ${stdout}`);
      console.error(`Script errors: ${stderr}`);
    });

    return config;
  },
};

In the above example, <Your command> represents the command to execute. Replace it with the appropriate command and ensure that you provide the correct path to your script.

6. Save the next.config.js file, and Next.js will now execute the command during hot reloading.