LernaJS Typescript cannot find module

Question

I'm trying to use LernaJS with typescript and I have some problems. When I try to run my package-1 which has package-2 as dependency I get the error:

    module.js:549
        throw err;
        ^
    
    Error: Cannot find module 'package-2'
        at Function.Module._resolveFilename (module.js:547:15)
        at Function.Module._load (module.js:474:25)
        at Module.require (module.js:596:17)
        at require (internal/module.js:11:18)
        at Object. (/home/gabriel/Documentos/projetos/nodejs/lerna-t2/packages/package-1/dist/index.js:3:19)
        at Module._compile (module.js:652:30)
        at Object.Module._extensions..js (module.js:663:10)
        at Module.load (module.js:565:32)
        at tryModuleLoad (module.js:505:12)
        at Function.Module._load (module.js:497:3)

I've followed the following steps:

I've created a directory and ran the command 'lerna init'
I've created 2 folders inside (package-1, package-2) 'packages' folder

    .
    ├── lerna.json
    ├── node_modules
    ├── package.json
    ├── package-lock.json
    └── packages
        ├── package-1
        └── package-2

I've ran 'npm init' in both (package-1, package-2)
I've created a basic 'tsconfig.json' in both packages:

    {
        "compilerOptions": {
            "outDir": "dist",
            "target": "es5",
            "module": "commonjs"
        }
    }

I've ran 'lerna bootstrap' in the root folder
I've use 'lerna add package-2 --scope=package-1'
I've ran also 'npm i' in root folder, package-1 and package-2
I've ran 'tsc -w' in package-1 and package-2 and 'node dist/index.js' in package-1

FILE TREE

My 'package-1' file tree:


    .
    ├── dist
    │   └── index.js
    ├── index.ts
    ├── node_modules
    │   ├── package-2 -> ../../package-2
    │   └── typescript
    ├── package.json
    ├── package-lock.json
    └── tsconfig.json

My 'package-2' file tree:


    .
    ├── dist
    │   ├── index.js
    │   └── lib
    │       └── teste.js
    ├── index.ts
    ├── lib
    │   └── teste.ts
    ├── package.json
    ├── package-lock.json
    └── tsconfig.json

CODE

package-1:

index.ts:


    import { Teste } from 'package-2'
    
    new Teste().printHello()

package-2:

lib/teste.ts:


    export class Teste {
    
        printHello() {
            console.log('Hello!')
        }
    
    }

index.ts:


    export { Teste } from './lib/teste'

score 34 · Accepted Answer · answered Jun 12 '18 at 05:33

34

Please ensure you have defined main in your package.json in (at least project-2). I assume the name field in package.json (for project-2) is project-2.

Main should link to dist/index.js

answered Jun 12 '18 at 05:33

lajtmaN

437
1
6
12

1

@lajtmaN: Please elaborate, what does it do and how do you come to this resolution? – Gegenwind Apr 16 '19 at 17:25
6

@Gegenwind That is how Lerna links the projects together. When you import another project from the Lerna repository, you are actually just importing whatever is defined in `main` in the package.json. AFAIK it is not possible to link directly to your index.ts file since the compiler expects the imported files to be compiled already. That's why you should use the compiled javascript file (often located in a folder named dist or build). – lajtmaN Apr 23 '19 at 05:53
1

Thank you very much, a very small detail I was missing :) – Jose Villalobos Jun 06 '19 at 18:31
@lajtmaN please explain what you mean by "Main should link to dist/index.js". I ask because I already defined main in all package.json files and still have this error. – bikeman868 May 22 '23 at 20:09

LernaJS Typescript cannot find module

1 Answers1

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