Cannot find module '/app/server.js'

[Shivamy2]

Not able to host on Heroku

node server.js
internal/modules/cjs/loader.js:905
throw err;
Error: Cannot find module '/app/server.js'
at Function.Module._resolveFilename (internal/modules/cjs/loader.js:902:15)
 at Function.Module._load (internal/modules/cjs/loader.js:746:27)
at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:76:12)
at internal/main/run_main_module.js:17:47 {
code: 'MODULE_NOT_FOUND',
requireStack: []
2021-11-04T06:04:22.376756+00:00 app[web.1]: }
npm ERR! code ELIFECYCLE
 npm ERR! errno 1
npm ERR! practica-server@1.0.0 start: `node server.js`
 npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the practica-server@1.0.0 start script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

package.json

"scripts": {
    "dev": "node ace serve --watch",
    "build": "node ace build --production",
    "start": "node server.js"
  },

[RomainLanz]

Hey @Shivamy2! 👋🏻

We will definitively more information to be able to help you.
In the meanwhile, check our documentation for Heroku deployment.

[akshaj65]

i am also getting the same error
if the error was resolved please help me also
thankyou

[yevheniib]

same here, i was getting Cannot find module '/app/server.js', followed stackoverflow article and added a procfile where specified the path to the file web: node src/server.js, so now i get Cannot find module '/app/src/server.js', why the /app, how to specify that that the main file is not in the /app?

[yevheniib]

the problem is gone, but I cannot provide the steps, sorry, I've reset up my express from up to bottom.

[JasminRdev]

How is express changing anything when u can't even reach the folder it was supposed to be inside??

[hansderly]

@JasminRdev i think the problem was because in the Procfile @yevheniib wrote web: node server.js, but that should be in the script of package.json. The Procfile just need to know the script name and should look like web: npm start, where start is the name of the script in package.json wich run node server.js.
RECAP>>>
package.json:

{
...
       "scripts": {
		"start": "node server.js",
		"dev": "nodemon server.js"
	},
...
}

Procfile:
web: npm start

Hope that helps.

[JasminRdev]

That's for that idea but that procfile wasn't the idea. Something completely different wasn't on a relative path. My Axios baseurl was instead as fixed domain.

F.e. baseURL = domain/API/notes is wrong but baseURL= API/notes was working.

[JasminRdev]

Thanks*

[radoncreep]

if you're using YARN as your pkg manager and typescript or even js, then;

In my case, I wrote a stupid instruction to use npm instead of yarn in my start script. Its possible npm couldn't read from the yarn.lock file because I included a package I never installed in my project, npm couldn't depict that and the logs from Heroku (sorry can't reproduce) looked like the image from @Shivamy2.

I changed to "yarn build && node " and from the logs on Heroku, yarn was able to depict I didn't install a pkg.
So yea, installing that pkg and deploying worked fine.

in Procfile
web: yarn start

in package.json
`
{
"main": "/server.js", // indicate the entry file for your build, you might call your outputDir "build" or "dist" or any from tsconfig file

"scripts": {
"start": "yarn run build && node dist/server.js",
"build": "rimraf ./dist && tsc", // use rimraf to efficiently remove old tsc build
"dev": "nodemon ./src/server.ts"
},
`

Hope this helps!

[observadorxpl]

Any solution?

[RomainLanz]

If you have this error, you are probably trying to run a file that does not exist. As said in the first comment, it is hard for us to help anyone without seeing the proper file structure deployed.

Double check where your server.js file resides.

[observadorxpl]

I found the problem, just add express dependency haha