Optimizing Lodash in Next.js with webpack and babel-plugin-lodash

Lodash is a popular JavaScript library that provides a rich set of utility functions for common programming tasks, such as manipulating arrays and objects, working with dates and times, and performing mathematical operations. In a Next.js project, it’s important to optimize the way Lodash is included to reduce the size of the bundle and improve performance.

Here are some strategies you can try:

• Use a tool like webpack or rollup to bundle your code and dependencies. These tools can help to reduce the size of the bundle by eliminating unused code and optimizing the code that is included.

• Use a tool like lodash-webpack-plugin or lodash-rollup-plugin to optimize the way Lodash is included in the bundle. These plugins allow you to include only the specific functions that you need, rather than the entire Lodash library, which can help to reduce the size of the bundle.

• Consider using a tool like babel-plugin-lodash to further optimize the way Lodash is included in the bundle. This plugin allows you to replace certain Lodash functions with equivalent, smaller, native JavaScript functions.

• Make sure to use the next/babel preset in your .babelrc file. This preset includes a number of plugins that can help to reduce the size of the bundle, including the babel-plugin-lodash plugin mentioned above.

Lodash-webpack-plugin

You can use lodash-webpack-plugin to optimize the way Lodash is included in a bundle created with webpack. lodash-webpack-plugin allows you to specify which functions from the Lodash library should be included in the bundle, which can help to reduce the size of the bundle by eliminating unnecessary functions.

To use lodash-webpack-plugin in a Next.js project, you will need to install it first. You can install it using npm or yarn:

    # using npm
    npm install --save-dev lodash-webpack-plugin

    # using yarn
    yarn add --dev lodash-webpack-plugin

Next, you will need to create a next.config.js file in the root of your project if you don’t already have one. In this file, you can configure the lodash-webpack-plugin by requiring it and adding it to the list of webpack plugins.

Here’s an example of how you might do this in a Next.js project:

const LodashModuleReplacementPlugin = require('lodash-webpack-plugin');

module.exports = {
    webpack: (config) => {
        config.plugins.push(new LodashModuleReplacementPlugin());
        return config;
    },
};

By default, lodash-webpack-plugin will include all of the functions in the Lodash library in the bundle. If you only want to include a subset of the functions, you can pass an options object to the plugin with a shorthands property set to false and a cloning property set to false. This will exclude the shorthand and cloning functions from the bundle:

const LodashModuleReplacementPlugin = require('lodash-webpack-plugin');

module.exports = {
    webpack: (config) => {
        config.plugins.push(new LodashModuleReplacementPlugin({
            shorthands: false,
            cloning: false,
        }));
        return config;
    },
};

You can also use the modularize property to specify which functions should be included in the bundle. For example, to include only the map and filter functions, you could do the following:

const LodashModuleReplacementPlugin = require('lodash-webpack-plugin');

module.exports = {
    webpack: (config) => {
        config.plugins.push(new LodashModuleReplacementPlugin({
            modularize: true,
            'map': 'map',
            'filter': 'filter',
        }));
        return config;
    },
};

babel-plugin-lodash

A simple transform to cherry-pick Lodash modules so you don’t have to.

Combine with lodash-webpack-plugin for even smaller cherry-picked builds!

To use babel-plugin-lodash in a Next.js project, you will need to install it first. You can install it using npm or yarn:

    # using npm
    npm install --save-dev babel-plugin-lodash

    # using yarn
    yarn add --dev babel-plugin-lodash

Next, you will need to configure Babel to use the babel-plugin-lodash plugin. In a Next.js project, you can do this by creating a .babelrc file in the root of your project and adding the plugin to the list of plugins.

Here’s an example of how you might configure babel-plugin-lodash in a Next.js project:

{
    "presets": ["next/babel"],
    "plugins": ["lodash"]
}

By default, babel-plugin-lodash will replace all of the Lodash functions in your code with equivalent, native JavaScript functions. If you only want to replace certain functions, you can pass an options object to the plugin with a lodash property set to an array of the functions you want to replace.

For example, to replace only the map and filter functions, you could do the following:

{
    "presets": ["next/babel"],
    "plugins": [
        ["lodash", { "lodash": ["map", "filter"] }]
    ]
}

In conclusion, Lodash is a popular JavaScript library that provides utility functions for common programming tasks. When using Lodash in a Next.js project, it’s important to consider strategies for optimizing its inclusion in the bundle, including using tools like webpack, rollup, lodash-webpack-plugin, babel-plugin-lodash, and npm/yarn. Lodash-webpack-plugin can help optimize the way Lodash is included in the bundle, while babel-plugin-lodash can replace certain Lodash functions with equivalent, smaller, native JavaScript functions. By implementing these strategies, developers can improve the performance and reduce the size of their Next.js applications.