patch-package

<p align="center">
  <img src="https://ds300.github.io/patch-package/patch-package.svg" width="80%" alt="patch-package" />
</p>

`patch-package` lets app authors instantly make and keep fixes to npm
dependencies. It's a vital band-aid for those of us living on the bleeding edge.

```sh
# fix a bug in one of your dependencies
vim node_modules/some-package/brokenFile.js

# run patch-package to create a .patch file
npx patch-package some-package

# commit the patch file to share the fix with your team
git add patches/some-package+3.14.15.patch
git commit -m "fix brokenFile.js in some-package"
```

Patches created by `patch-package` are automatically and gracefully applied when
you use `npm`(>=5) or `yarn`.

No more waiting around for pull requests to be merged and published. No more
forking repos just to fix that one tiny thing preventing your app from working.

## Set-up

In package.json

```diff
 "scripts": {
+  "postinstall": "patch-package"
 }
```

Then

### npm

    npm i patch-package

You can use `--save-dev` if you don't need to run npm in production, e.g. if
you're making a web frontend.

### yarn v1

    yarn add patch-package postinstall-postinstall

You can use `--dev` if you don't need to run yarn in production, e.g. if you're
making a web frontend.

To understand why yarn needs the `postinstall-postinstall` package see:
[Why use postinstall-postinstall](#why-use-postinstall-postinstall-with-yarn)

### yarn workspaces

Same as for yarn ☝️ Note that if you want to patch un-hoisted packages you'll
need to repeat the setup process for the child package. Also make sure you're in
the child package directory when you run `patch-package` to generate the patch
files.

### yarn v2+

yarn 2+ have native support for patching dependencies via
[`yarn patch`](https://yarnpkg.com/cli/patch). You do not need to use
patch-package on these projects.

### pnpm

pnpm has native support for patching dependencies via
[`pnpm patch`](https://pnpm.io/cli/patch). You do not need to use patch-package
on these projects.

### Heroku

For `patch-package` to work on Heroku applications, you must specify
[`NPM_CONFIG_PRODUCTION=false` or `YARN_PRODUCTION=false`](https://devcenter.heroku.com/articles/nodejs-support#package-installation).
See [this issue](https://github.com/ds300/patch-package/issues/130) for more
details.

### Docker and CI

- If having errors about working directory ("cannot run in wd [...]") when
  building in Docker, you might need to adjust configuration in `.npmrc`. See
  [#185](https://github.com/ds300/patch-package/issues/185).
- In your `Dockerfile`, remember to copy over the patch files _before_ running
  `[npm|yarn] install`
- If you cache `node_modules` rather than running `yarn install` every time,
  make sure that the `patches` dir is included in your cache key somehow.
  Otherwise if you update a patch then the change may not be reflected on
  subsequent CI runs.

### CircleCI

Create a hash of your patches before loading/saving your cach