Module build failed in babel babel-loader

Explanation of the problem

Upon execution of the command npm install -D babel-loader @babel/core @babel/preset-env to install new Babel packages after uninstalling all previous Babel packages, the following compilation error was encountered:

ERROR in ./src/index.js
Module build failed (from ./node_modules/babel-loader/lib/index.js):
Error: .plugins[3][2] must be a string, or undefined
    at assertPluginItem (C:\_TFS\EP\ConnectorV2\Dev\Connector.UI\node_modules\@babel\core\lib\config\validation\option-assertions.js:252:15)
    at arr.forEach (C:\_TFS\EP\ConnectorV2\Dev\Connector.UI\node_modules\@babel\core\lib\config\validation\option-assertions.js:222:30)
    at Array.forEach (<anonymous>)
    at assertPluginList (C:\_TFS\EP\ConnectorV2\Dev\Connector.UI\node_modules\@babel\core\lib\config\validation\option-assertions.js:222:9)
    at Object.keys.forEach.key (C:\_TFS\EP\ConnectorV2\Dev\Connector.UI\node_modules\@babel\core\lib\config\validation\options.js:107:5)
    at Array.forEach (<anonymous>)
    at validateNested (C:\_TFS\EP\ConnectorV2\Dev\Connector.UI\node_modules\@babel\core\lib\config\validation\options.js:83:21)
    at validate (C:\_TFS\EP\ConnectorV2\Dev\Connector.UI\node_modules\@babel\core\lib\config\validation\options.js:74:10)
    at file (C:\_TFS\EP\ConnectorV2\Dev\Connector.UI\node_modules\@babel\core\lib\config\config-chain.js:174:34)
    at cachedFunction (C:\_TFS\EP\ConnectorV2\Dev\Connector.UI\node_modules\@babel\core\lib\config\caching.js:33:19)
 @ multi react-hot-loader/patch ./src/index.js main[1]
Child html-webpack-plugin for "index.html":
         Asset     Size  Chunks  Chunk Names
    index.html  576 KiB       0
    Entrypoint undefined = index.html
    [./node_modules/html-webpack-plugin/lib/loader.js!./src/assets/index.template.ejs] 445 bytes {0} [built]
        single entry C:\_TFS\EP\ConnectorV2\Dev\Connector.UI\node_modules\html-webpack-plugin\lib\loader.js!C:\_TFS\EP\ConnectorV2\Dev\Connector.UI\src\assets\index.template.ejs
    [./node_modules/lodash/lodash.js] 528 KiB {0} [built]
        cjs require !!../../node_modules/lodash/lodash.js [./node_modules/html-webpack-plugin

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Problem solution for Module build failed in babel babel-loader

The issue of Module build failed in babel-loader can be caused by various reasons such as incorrect version of babel packages, misconfigured .babelrc file, incorrect preset options, etc.

To solve this issue, follow these steps:

1. Check if you have installed the correct versions of babel packages, including babel-loader, @babel/core, and @babel/preset-env.
2. Verify that your .babelrc file is correctly configured with the correct preset options.
3. If you are using webpack, make sure that the babel-loader is correctly set up in your webpack.config.js file.
4. If you are still encountering the issue, try deleting the node_modules folder and the package-lock.json file, and then run npm install again.
5. If none of the above steps works, you may want to consider posting the error message, your package.json file, and your webpack.config.js file to a relevant forum or community for further help.

Other popular problems with babel babel-loader

A brief introduction to babel babel-loader

Babel is a JavaScript compiler that is commonly used to transpile modern JavaScript syntax into an older syntax that is supported by older browsers and environments. Babel-loader is a webpack module that integrates Babel into the webpack build process, allowing developers to use modern JavaScript syntax in their code, while still being able to target older browsers.

The babel-loader module is highly configurable, allowing developers to choose which syntax and features to transpile, and to define custom transformations. This makes it an essential tool for modern JavaScript development, as it enables developers to use the latest language features, while still ensuring that their code will run in older environments. Additionally, the integration with webpack means that the transpilation process is highly optimized, so it is fast and efficient, even for large codebases.

Most popular use cases for babel babel-loader

1. Transpiling of modern JavaScript syntax to backward compatible syntax: Babel-babel-loader allows developers to write code in the latest version of JavaScript, including new syntax such as async/await and destructuring, and transpile it to an older version that is supported by a wider range of browsers. This enables developers to take advantage of the latest features and capabilities of JavaScript while still ensuring compatibility with older browsers.
2. Code Optimization: Babel-babel-loader can be used to optimize code for performance by transforming code into a more efficient form. This can include removing dead code, minifying code, and transforming code into a more performant format.
3. Modularizing Code: Babel-babel-loader can be used to modularize code by transforming CommonJS or AMD style code into a more modern format such as ECMAScript modules. This allows developers to write reusable, modular code that is more maintainable and can be imported and used in different parts of an application. For example, the following code block:

// CommonJS code
const React = require("react");

module.exports = function MyComponent() {
  return <div>Hello, World!</div>;
};

Can be transformed into the following using Babel-babel-loader:

// ECMAScript modules
import React from "react";

export default function MyComponent() {
  return <div>Hello, World!</div>;
};