Javascript you may need an additional loader

Question

We are working on the following module js(javascript only), which allows to generate random colors. Link: Github

When we try to install the module on an example on codesandbox, we have no problem.

But when we install the module on a local project, we get the following error:

./node_modules/random-colors-palette/randomColors.js 141:39
Module parse failed: Unexpected token (141:39)
File was processed with these loaders:
 * ./node_modules/react-scripts/node_modules/babel-loader/lib/index.js
You may need an additional loader to handle the result of these loaders.
|     if (!repeat) {
|       delete cc[hueNumber].shades[shadeR[0]];
>       if (Object.entries(cc[hueNumber]?.shades).length === 0) cc.splice(hueNumber, 1);
|     }
|

The problem seems to be due to the use of the ? (The optional concatenation operator) in the line in question.

How can we solve the problem, do I need to add some other files in the project configuration to make sure I don't have these problems?

The module should not only be used for reactjs, but also as a module pure js code.

Can you give us a hand?

Answer 1

You need babel-plugin-proposal-optional-chaining.

It is included in ES2020 babel preset.

Your .babelrc should be

{
  "presets": ["es2020"]
}

If you don't use a preset add the plugin manually to your babel config