Unexpected Token Export: Embracing ES6 Module Support

Encountering the "Unexpected Token Export" error while attempting to run ES6 code can be a perplexing issue. This error arises when the runtime environment lacks support for the EcmaScript Module (ESM) syntax you're using.

Understanding ESM:

ESM, often referred to as "ES6 Modules," introduced a module system for JavaScript, enabling code encapsulation and easier dependency management. It utilizes the export keyword to define modules, making code organization more explicit.

Support for ESM:

NodeJS versions below v14.13.0 did not support ESM and instead relied on CommonJS Modules, which used the module.exports property syntax. However, newer NodeJS versions (v14.13.0 and above) support ESM, provided it is explicitly enabled.

Solutions:

Enable ESM in NodeJS (v14.13.0 ):

Edit your project's package.json file and set the "type" property to "module":

{
  ...
  "type": "module",
  ...
}

Refactor with CommonJS Module Syntax:

For older NodeJS versions, refactor your code to use the CommonJS module syntax:

// Example ES6 module
export class MyClass {
  constructor() {
    console.log("es6");
  }
}

// CommonJS module equivalent
module.exports = class MyClass {
  constructor() {
    console.log("commonJs");
  }
};

Utilize TypeScript and ts-node:

Consider using TypeScript alongside the ts-node or ts-node-dev npm packages. TypeScript transpiles to JavaScript at compile time, making ES6 code compatible with older NodeJS versions.

Transpile ESM to CommonJS:

Use esbuild (installed via npm) to transpile your ES6 JavaScript to CommonJS format, allowing it to run in environments without native ESM support.