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Comment by warent | Hacker News Reader

This seems like a super edge case or antipattern anyway. I've worked with Node.js for several years and can't think of a time I've patched my local node_modules, because a) how would I ensure they're not overwritten in the next npm install, and b) how would I share those changes with the team

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patch-package is a tool for this specific purpose

https://www.npmjs.com/package/patch-package

You commit your changes as a diff text file and add the patch-package command to your post-install hook so it runs after every install

My main use for it is fixing other packages' package.json exports field and Typescript definitions

Interesting, I can definitely see this being particularly useful for typescript fixes.

Where should one put the text files in the code base? Do you create some root level "patch" directory?

patch-package automatically makes a `patches` directory at the top level of your project with `{package-name}+{package-version}.patch` files in it.

yes

One widely-used example is Angular. (It may have changed, I’m not entirely up-to-date.) The Angular Compatibility Compiler (ngcc) creates optimized code of Angular component libraries right next to the original files inside node_modules. It does this automatically as part of the Angular build process.

That’s also how I would share any patches: Just apply them when needed during the build process. NPM doesn’t care about what changes inside packages, so you can hack them all you want.

It's more common than you'd think. Consider the case of an app that consumes a component library. One is building a component in one project, and then consuming it in another project. `npm link` makes this trivial. While I totally prefer building things in isolation, there are often little edge cases that crop up once a library is added to an app. Sometimes it's easier just to consume a lib in a "real world scenario".

I can think of at least three times I've had to do this, across ~7 years of working with Node. It's an awful hack, but when you need it, you need it.

It's not uncommon but you most likely fork the package then "npm i https://guthub.com/account/forked_package"

A popular choice if you need some pr's that aren't (going to be) merged.

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