How do I modify a node module and use that in Vercel?

[shajidhasan]

During every build, Vercel downloads all the dependencies so I can't just edit a local file in my node_modules and expect that to have any effect in Vercel. I have tried patch-package as a postinstall script but patch-package doesn't work during a Vercel build. So how to go around this problem?

[barelyhuman]

1. easiest one, fork the original package, modify source, use your git repo as the dependency in package.json.
2. ruins the ease but instead of using the vercel web , use the cli command to run the setup instead and the patch-package should work fine here.
3. Use a simple shell script to make the needed changes before the actual build.

3rd one works because the build step is run after the environment is setup up which is where the installation of the packages go through and you can just change you build step in Project Settings > General , to run the shell script, before it runs the build command.

examples: npx patch-package; npm run build or ./patch.sh; npm run build

let me know if that works

[amyegan]

Hi @Bhaney44! Is the package published publicly, or is it a private package/repo? If it is private then you will need to provide a token to allow it to install. The guide How do I use private dependencies with Vercel? has more information. GitHub Packages documentation on working with the npm registry might also be helpful.

[Bhaney44]

Hi @amyegan - thanks for the reply! Thanks for the helpful documentation. The GitHub was public, so I'm not sure why there would be an issue. I ended up solving this issue by changing the dependencies, which allowed me to avoid the need to use a fix in node modules. But, this is helpful because I am sure I will run into the problem again.

[amyegan]

I'm glad you found a solution that works for your app!

[barelyhuman]

Thanks @amyegan ,
apparently mail notifications are off

@Bhaney44 If you could let me know what you were using as a format for the package dep that might be the issue.

I normally use git+ssh://git@github.com/<username>/<repo>.git and while testing locally make sure the installed deb does actually build itself if necessary.

Also, yarn, npm and pnpm have a slightly different approach at git deps so you might wanna stick to a single dep manager for this and only it's lock file.

Hopefully that helps in the future, if you wish to try something like this again

[Bhaney44]

Thanks @amyegan , apparently mail notifications are off

@Bhaney44 If you could let me know what you were using as a format for the package dep that might be the issue.

I normally use git+ssh://git@github.com/<username>/<repo>.git and while testing locally make sure the installed deb does actually build itself if necessary.

Also, yarn, npm and pnpm have a slightly different approach at git deps so you might wanna stick to a single dep manager for this and only it's lock file.

Hopefully that helps in the future, if you wish to try something like this again

Thanks for your help. I think you're right - it was my formatting.

"react-scripts": "git://github.com/ChoiceCoin/react-scripts.git", (works locally)(failed via Vercel)
"react-scripts": "git:https://github.com/ChoiceCoin/react-scripts", (failed)
"react-scripts": "git:ChoiceCoin/react-scripts", (failed)

In the future, I will run:

git+ssh://git@github.com/<username>/<repo>.git

Thanks!

[beadlespouse]

Looks like patch-package is now working on vercel! Much easier than forking...

[TimTJoe]

sure!