Uglifyjs Throws Unexpected Token Keyword Const With Node_modules

Have you ever encountered the frustrating "Unexpected token 'const'" error when using UglifyJS with Node_modules? Don't worry; you're not alone. This common issue can be confusing to deal with, but with a bit of know-how, you can quickly resolve it and get back to coding without a hitch.

When you're working on a project that involves minifying your JavaScript files using UglifyJS, you might come across this error message. The reason behind this error is that UglifyJS doesn't support some of the newer ES6 syntax features by default, such as the 'const' keyword. However, there's a simple solution to this problem.

To fix the "Unexpected token 'const'" error, you need to inform UglifyJS that you want to support ES6 syntax. This can be achieved by using the `ecma` option when running UglifyJS.

First, ensure you have UglifyJS installed in your project. If not, you can add it using npm:

npm install uglify-es --save-dev

Next, when running UglifyJS, add the `ecma` option to indicate the ECMAScript version you want to support. To enable ES6 syntax, set `ecma` to 6:

uglifyjs yourfile.js --compress --mangle --ecma 6 -o output.js

By setting the `ecma` option to 6, UglifyJS will now recognize ES6 syntax features like 'const' and successfully minify your JavaScript code without throwing any unexpected token errors.

It's essential to remember that by enabling ES6 support in UglifyJS, you can take advantage of the latest JavaScript features while still optimizing your code for performance. This way, you can write modern JavaScript code without worrying about compatibility issues when minifying it for production.

Additionally, if you're working with Node_modules and encounter this error, you may need to specify the correct path to the module in your UglifyJS command. Make sure to provide the relative or absolute path to the file you want to minify to avoid any path-related errors.

In conclusion, the "Unexpected token 'const'" error when using UglifyJS with Node_modules is a common issue that can be easily resolved by configuring UglifyJS to support ES6 syntax. By following the steps outlined above and specifying the `ecma` option with the desired ECMAScript version, you can ensure a smooth minification process without any unexpected token errors.

I hope this guide helps you tackle the "Unexpected token 'const'" error and empowers you to continue building amazing projects with confidence. Happy coding!