Скачать или смотреть How to Fix webpack Error: Cannot find module on Node.js (webpackEmptyContext)

A comprehensive guide on resolving the `Cannot find module` error in webpack for Node.js projects, particularly when using third-party libraries like Lighthouse.
---
This video is based on the question https://stackoverflow.com/q/63670297/ asked by the user 'Yaron' ( https://stackoverflow.com/u/6516970/ ) and on the answer https://stackoverflow.com/a/63670482/ provided by the user 'tmhao2005' ( https://stackoverflow.com/u/3104226/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: How to fix webpack Error: Cannot find module - on node.js (webpackEmptyContext)

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
How to Fix webpack Error: Cannot find module on Node.js (webpackEmptyContext)

When working with Node.js applications that utilize webpack for module bundling, encountering errors can be frustrating, especially when those errors arise from third-party libraries. A common issue developers face is the Cannot find module error, specifically in the context of the webpackEmptyContext. In this guide, we will explore this problem in detail and guide you step-by-step on how to resolve it.

Understanding the Problem

The Cannot find module error typically occurs when a module required by your code cannot be located by webpack during the build process. In this case, the error was raised from a third-party library, Lighthouse, which suggests a misconfiguration in the webpack setup. Here’s a breakdown of the error message:

[[See Video to Reveal this Text or Code Snippet]]

This means that while trying to reference the css-usage module in the Lighthouse library, webpack was unable to find it, leading to the error.

Solution: Configure webpack with webpack-node-externals

To resolve the Cannot find module error effectively, especially when targeting Node.js, you can use the package webpack-node-externals. This tool helps you ignore all modules in the node_modules folder, which is particularly useful to prevent conflicts with external libraries that are not directly under your control.

Step 1: Install the Package

First, you need to install the webpack-node-externals package. Run the following command in your terminal:

[[See Video to Reveal this Text or Code Snippet]]

Using --save-dev ensures that it is added as a development dependency, which is suitable for build tools.

Step 2: Update Your webpack.config.js

Next, you will need to modify your webpack.config.js file to include the externals configuration. Here’s how you can do it:

Require the webpack-node-externals at the top of your config file.

Add the externals property to the module exports.

Your updated webpack.config.js should look like this:

[[See Video to Reveal this Text or Code Snippet]]

Step 3: Build Your Project Again

After making these changes, go ahead and build your project again. Use the following command in your terminal:

[[See Video to Reveal this Text or Code Snippet]]

Then run your Node.js application. With the changes in place, the Cannot find module error should be resolved, and your application should work correctly, leveraging the third-party Lighthouse library without issues.

Conclusion

Facing a Cannot find module error in a Node.js project using webpack can be daunting, especially when it is linked to third-party libraries like Lighthouse. However, through the use of webpack-node-externals, you can effectively manage your dependencies and avoid conflicts in your build process. By following the steps outlined in this guide, you should be able to eliminate the error and ensure your Node.js app builds successfully. If you have any further questions or need assistance, feel free to leave a comment below!