CODEWITHSUNDEEP
node.jstypescriptheroku
Xameer
Xameer

Reputation: 31237

Heroku deployment crashes for a non-required node module

I have a typescript express project which I need to deploy to Heroku.

This project is working absolutely fine on the local machine however when deploying the same to Heroku it throws this strange error:

> [email protected] start /app
> node -r module-alias/register ./dist --env=production
internal/modules/cjs/loader.js:969
throw err;
^
Error: Cannot find module 'tslib'
Require stack:
- /app/dist/index.js
     at Function.Module._resolveFilename (internal/modules/cjs/loader.js:966:15)
     at Function.Module._resolveFilename (/app/node_modules/module-alias/index.js:49:29)
     at Function.Module._load (internal/modules/cjs/loader.js:842:27)
     at Module.require (internal/modules/cjs/loader.js:1026:19)
     at require (internal/modules/cjs/helpers.js:72:18)
     at Object.<anonymous> (/app/dist/index.js:3:17)
     at Module._compile (internal/modules/cjs/loader.js:1138:30)
     at Object.Module._extensions..js (internal/modules/cjs/loader.js:1158:10)
     at Module.load (internal/modules/cjs/loader.js:986:32)
     at Function.Module._load (internal/modules/cjs/loader.js:879:14) {
   code: 'MODULE_NOT_FOUND',
   requireStack: [ '/app/dist/index.js' ]

to my surprise - tslib does not exist in the entire application code!!!

This means it should not be a required module as the node should take care of the execution.

As per the recommendations on the web,

Still, the error scenario remains unchanged!

Any ideas why is my deployment crashing?

Upvotes: 2

Views: 443

Answers (1)

Derek Alvarado
Derek Alvarado

Reputation: 102

npm install --save tslib got me past this problem.

For me, I had to explicitly add tslib as a runtime dependency. Even though tslib was available locally, it seems the heroku cli does a tree shaking process where it removes node modules that it doesn't think are necessary.

Upvotes: 5

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