Using compilerOptions: paths does not work with node

Question

Very similar to this question, but not a duplicate IMHO when using node:

$ tree .                                        
.
├── src
│   ├── main.ts
│   └── utils
│       └── myUtils.ts
└── tsconfig.json

I'm trying to use a @ import like so:

$ cat src/main.ts 
import { myLovelyUtilsFunction } from "@folder1/myUtils"
const y = myLovelyUtilsFunction();
console.log(`>>> ${y}`);

My tsconfig.json looks right, mapping @folder1 where it should:

{
  "compilerOptions": {
    "baseUrl": "src",
    "paths": { "@folder1/*": ["utils/*"] },
    "module": "commonjs"
  }
}

Transpilation goes fine, but running node doesn't:

$ npx tsc -p tsconfig.json # <--- no errors
$ node src/main.js
node:internal/modules/cjs/loader:1078
  throw err;
  ^

Error: Cannot find module '@folder1/myUtils'
Require stack:
< ... omitted ... > 

Answer 1

I think you need tsconfig-paths or ts-nodeto get your module resolution work properly.

Modify your tsconfig.json

{
  "compilerOptions": {
    "baseUrl": "./",
    "paths": { "@folder1/*": ["src/utils/*"] },
    "module": "commonjs"
  },
  "include": ["src/**/*"],
  "exclude": ["node_modules", "**/*.spec.ts"]
}

You also need to create an entry file point, which will use tsconfig-paths to resolve the paths.

index.ts

import 'tsconfig-paths/register';
import './src/main';

Update your package.json and then run to test.

{
  "scripts": {
    "start": "node index.js"
  }
}

The structure of your project could look like this now

.
├── src/
│   ├── main.ts
│   ├── utils/
│   │   └── myUtils.ts
├── tsconfig.json
├── package.json
├── index.ts