NPM errors after successfully building and deploying rails app to heroku - ruby-on-rails

Question

I've been working on a rails app using google-maps-4-rails to visualize the bicycle stations. The app worked fine on my local server, but I am getting errors while deploying to Heroku. I tried launching it locally in production environment but it works correctly. I am at loss, and since it is my first venture into front-end, I don't know how to handle this situation.
I've added the nodejs buildpack earlier to solve some other issue, maybe it's causing problems. I also formated the package.json, though I am not entirely sure if it's correct. Earlier problems were connected to yarn not being available on heroku.
My package.json :
{
"name": "sample_app",
"private": true,
"engines": {
"yarn": "1.7.0"
},
"scripts": {
"start": "node server"
},
"dependencies": {},
"keywords": [
"node",
"heroku"
]
}
My logs from heroku :
: Starting process with command `npm start`
2019-04-20T09:54:42.459328+00:00 heroku[web.1]: State changed from starting to crashed
2019-04-20T09:54:42.009377+00:00 app[web.1]:
2019-04-20T09:54:42.009398+00:00 app[web.1]: > sample_app# start /app
2019-04-20T09:54:42.009399+00:00 app[web.1]: > node server
2019-04-20T09:54:42.009401+00:00 app[web.1]:
2019-04-20T09:54:42.337386+00:00 app[web.1]: internal/modules/cjs/loader.js:584
2019-04-20T09:54:42.337425+00:00 app[web.1]: throw err;
2019-04-20T09:54:42.337427+00:00 app[web.1]: ^
2019-04-20T09:54:42.337429+00:00 app[web.1]:
2019-04-20T09:54:42.337431+00:00 app[web.1]: Error: Cannot find module '/app/server'
2019-04-20T09:54:42.337433+00:00 app[web.1]: at Function.Module._resolveFilename (internal/modules/cjs/loader.js:582:15)
2019-04-20T09:54:42.337434+00:00 app[web.1]: at Function.Module._load (internal/modules/cjs/loader.js:508:25)
2019-04-20T09:54:42.337436+00:00 app[web.1]: at Function.Module.runMain (internal/modules/cjs/loader.js:754:12)
2019-04-20T09:54:42.337438+00:00 app[web.1]: at startup (internal/bootstrap/node.js:283:19)
2019-04-20T09:54:42.337439+00:00 app[web.1]: at bootstrapNodeJSCore (internal/bootstrap/node.js:622:3)
2019-04-20T09:54:42.343303+00:00 app[web.1]: npm ERR! code ELIFECYCLE
2019-04-20T09:54:42.343921+00:00 app[web.1]: npm ERR! errno 1
2019-04-20T09:54:42.345414+00:00 app[web.1]: npm ERR! sample_app# start: `node server`
2019-04-20T09:54:42.345427+00:00 app[web.1]: npm ERR! Exit status 1
2019-04-20T09:54:42.349073+00:00 app[web.1]: npm ERR!
2019-04-20T09:54:42.349078+00:00 app[web.1]: npm ERR! Failed at the sample_app# start script.
2019-04-20T09:54:42.349081+00:00 app[web.1]: npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
2019-04-20T09:54:42.352338+00:00 app[web.1]:
2019-04-20T09:54:42.352554+00:00 app[web.1]: npm ERR! A complete log of this run can be found in:
2019-04-20T09:54:42.353207+00:00 app[web.1]: npm ERR! /app/.npm/_logs/2019-04-20T09_54_42_347Z-debug.log
2019-04-20T09:54:42.440910+00:00 heroku[web.1]: Process exited with status 1
I am not sure what files may be helpful, please let me know If I can provide any other that would be of assistance

Answer 1

Heroku thinks your Rails app is a Nodejs app because there is a package.json file and no Procfile. That package.json file should be completely unnecessary for a Rails app, try removing it.