Styled components not working with ReactJS library as an esm module

[SrinivasPrabhu794]

In my PHP app, I use a javascript ESM module made out of React Library (library target).

I have tested different functionalities and they all work but when I try to use styled components in my app it fails with this error:

Failed to resolve module specifier "process". Relative references must start with either "/", "./", or "../".

I have also used to the module babel-plugin-styled-components, and my .babelrc consists of the following lines.

{
  "plugins": ["babel-plugin-styled-components"]
}

Not sure why this happens, as I am unable to get to any solution. It seems like there is some dependency for the process library in styled-components which does not work out of the box. Can you please confirm if anyone has faced this issue?

[SrinivasPrabhu794]

Hi,

Any help with this will be valuable. Is this a known bug ?

[SrinivasPrabhu794]

It seems like the code was encountering a module resolution issue with Parcel when using Styled Components in a React-based library within the main PHP application. This error might be related to the "process" module, which is typically a Node.js global object and not available in the browser environment.

To fix this issue, these are the steps I followed:

Install the browser-process-hrtime and process packages:

npm install browser-process-hrtime process

Create a shim.js file in your React library's source folder:

// src/shim.js
if (typeof process === 'undefined') {
  var process = require('process');
  process.hrtime = require('browser-process-hrtime');
  window.process = process;
}

Import this shim.js file at the very top of your React library's entry point:

// src/index.js
import './shim';
// other imports and code

Update your package.json to include the browser field:

{
  "browser": {
    "process": "process/browser"
  },
  // rest of the package.json content
}

This solution adds a browser-compatible version of the process module, and the browser-process-hrtime package provides a browser-compatible version of the process.hrtime function.

After following these steps, rebuild the project and check the browser console