Expressjs App on Vercel, not installing peer dependencies - node.js

Question

I'm building a small expressjs app that I host on vercel. Testing the app locally works fine, but when deploying and running on vercel, the require stack fails on my serverless function.
This is what vercel tells me :
2023-02-03T14:41:20.325Z undefined ERROR Cannot find module 'ndarray-pixels'
Require stack:
- /var/task/node_modules/#gltf-transform/functions/dist/functions.js
- /var/task/_index.js
My package.json looks like this
{
"name": "test - app",
"version": "1.0.0",
"description": "",
"main": "_index.js",
"scripts": {
"start": "node --experimental-fetch _index.js"
},
"keywords": [],
"author": "",
"license": "ISC",
"dependencies": {
"#gltf-transform/core": "^2.5.1",
"#gltf-transform/extensions": "^2.5.1",
"#gltf-transform/functions": "^2.5.1",
"cors": "^2.8.5",
"express": "^4.18.2",
"fetch": "^1.1.0",
"gl-matrix": "^3.4.3",
"ktx-parse": "^0.4.5",
"ndarray-pixels": "^1.0.0",
"node-fetch": "^2.6.9",
"three": "^0.148.0"
}
}
.
I've tried adding the build override on vercel, with no luck.
npm install --legacy-peer-deps
Any help or pointers are much appreciated

Answer 1

This problem can happen if you accidentally send the node_modules folder to the git remote repository. If it is the case, remove the node_modules folder, create a .gitignore file if it not exists and just write node_modules inside the gitignore file.
Now you can:
git rm -r --cached .
git add --all .
git commit -a -m "Versioning untracked files"
git push