CODEWITHSUNDEEP
node.jstypescript
Andrea Costanzo
Andrea Costanzo

Reputation: 2235

Exclude file from "isolated modules" in tsconfig.json

I'm building a node.js application using worker_threads under the hood. In the script file, called worker.ts, I cannot use the import statement because Node throws an error. So I'm importing the needed packages like this:

const { parentPort } = require('worker_threads')

parentPort.on('message', (data) => {
    //Non relevant code
})

However, despite the code actually working, the following error is displayed since there is neither an import nor an export statement:

'worker.ts' cannot be compiled under '--isolatedModules' because it is considered a global script file.

How can I solve the issue?

Upvotes: 0

Views: 422

Answers (1)

jsejcksn
jsejcksn

Reputation: 33901

Using the CodeSandbox link that you provided as a reference, I'll explain the changes that need to be made in both TypeScript modules in order for compilation to succeed and for the program to execute successfully:

./src/index.ts:

// Use import statements: TypeScript will transform them into "require" calls
// because you are targeting CommonJS in your TSConfig
import {Worker} from 'worker_threads';
import * as path from 'path';

const worker = new Worker(path.resolve(__dirname, './worker.js'));
/*                                                         ^^^
                      It is important to use the path of the **COMPILED** file,
                      and the extension of the compiled file will be ".js"    */
worker.on('message', (data) => console.log('Main: ' + data));
worker.postMessage('Hello!');

./src/worker.ts:

// Again, use import statement
import {parentPort} from 'worker_threads';

parentPort.on('message', (data) => {
  console.log('Worker: ' + data);
  setTimeout(() => parentPort.postMessage(data), 1000);
});

Run:

# $ cd path/to/project/dir
$ tsc && node dist/index.js
Worker: Hello!
Main: Hello!

Upvotes: 1

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