Heroku MERN deployment. Error: Cannot find module

The deployment is successful but the it cannot find modules.

I suppose that the problem might be in the project structure I am using:

  ├── LICENSE  ├── README.md  ├── client  │   ├── README.md  │   ├── build  │   ...  │   ├── package-lock.json  │   ├── package.json  │         ├── package.json  └── server      ├── main.js      ├── package-lock.json      ├── package.json      ├── routes      │  ...  

I have 3 package.json files. One in client, one in server (having all of the dependencies) and one at the root of the project specifically for heroku to work. The one in the root has only heroku-postbuild and other scripts and does not have any dependencies. All of the deplendencies needed are in the server/package.json.

The deployment went successfully, but it crushes saying that it cannot find a module (dotenv specifically) that is used in the server/main.js

https://stackoverflow.com/questions/67248849/heroku-mern-deployment-error-cannot-find-module April 25, 2021 at 09:04AM