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Error TS2307: Cannot find module events

If you're extending the `EventEmitter` class from Node.js and encounter the error TS2307 or TS2339, it means you're missing the Node.js type definitions. To fix this, install the typings by running `yarn add @types/node@12 --dev --tilde`. This solution has been tested with TypeScript 3.9.3 and Node.js 12.18.0 LTS.

Extending the EventEmitter class from Node.js might cause error TS2307. Here is how to fix it.

Contents

Problem

In Node.js you can implement an event listener system using the EventEmitter class:

import { EventEmitter } from 'events';
 
enum TOPIC {
  TEST = 'EmitterTest.TOPIC.TEST',
}
 
export interface EmitterTest {
  on(event: TOPIC.TEST, listener: (message: string) => void): this;
}
 
export class EmitterTest extends EventEmitter {
  public static readonly TOPIC = TOPIC;
 
  constructor() {
    super();
  }
 
  emitSomething(): void {
    this.emit(EmitterTest.TOPIC.TEST, 'this-is-a-test');
  }
}
 
// Execution
 
const emitter = new EmitterTest();
 
emitter.on(EmitterTest.TOPIC.TEST, (message) => {
  console.log(`This callback received message: ${message}`);
});
 
emitter.emitSomething();

When executing the code above you may encounter the following errors:

Cannot find module 'events' or its corresponding type declarations.

Property 'emit' does not exist on type ...

Solution

Most of the times these errors are symptoms of missing Node.js type definitions. You can resolve these problems by installing the following typings:

yarn add @types/node@12 --dev --tilde

Tested with TypeScript 3.9.3 and Node.js 12.18.0 LTS.

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