Make react-native peerDependency optional

[trivikr]

Is your feature request related to a problem? Please describe.

When a project depends on react-native-url-polyfill and uses npm v7, the react-native peerDependency is installed by default. This happens as npm v7 automatically installs peer dependencies.

The npm v7 was made generally available on February 2, 2021, and is shipped with latest versions of Node.js

This is a problem, as some packages which depend on react-native-url-polyfill may support all JavaScript platforms in a single package. Even if the consumers of those packages do not need support for react-native, the react-native dependency will be installed by default in npm v7.

An example is AWS SDK for JavaScript (v3) which supports Node.js, browser and react-native platforms in a single package.

Describe the solution you'd like

Use peerDependenciesMeta configuration to set react-native dependency as optional in package.json as follows:

{
  // ...
  "peerDependencies": {
    "react-native": "*"
  },
  "peerDependenciesMeta": {
    "react-native": {
      "optional": true
    }
  },
  // ...
}

The peerDependenciesMeta is supported in:

• npm https://docs.npmjs.com/cli/v7/configuring-npm/package-json#peerdependenciesmeta
• yarn https://classic.yarnpkg.com/en/docs/package-json/#toc-peerdependencies
• yarn v2 https://yarnpkg.com/configuration/manifest#peerDependenciesMeta
• pnpm https://pnpm.js.org/package_json/#peerdependenciesmeta

Describe alternatives you've considered

Setting react-native-url-polyfill as optional in projects which consume it.
Example in aws-sdk-js-v3 with another polyfill react-native-get-random-values aws/aws-sdk-js-v3#2108

Additional context

• The AWS SDK for JavaScript (v3) is exploring using react-native-url-polyfill in Use react-native-url-polyfill instead of deprecated url.parse in url-parser-native aws/aws-sdk-js-v3#2138
• This issue occurs with another polyfill react-native-get-random-values when AWS SDK for JavaScript (v3) is installed using npm v7 Trim production dependencies aws/aws-sdk-js-v3#1536. The request on react-native-get-random-values repo Make react-native peerDependency optional LinusU/react-native-get-random-values#27

[trivikr]

The RFC on yarn package manager which had introduced peerDependenciesMeta https://github.com/yarnpkg/rfcs/blob/master/accepted/0000-optional-peer-dependencies.md

[charpeni]

Oh, that’s really interesting! Thanks for your detailed issue, I wasn’t aware of that feature at all.

I like the solution you described.

[trivikr]

Closing this request, as react-native is a required peer dependency for react-native-url-polyfill

The platform independent consumers (like aws-sdk-js-v3) which require react-native-url-polyfill for React Native support should make their peerDependency on react-native-url-polyfill optional instead. The consumers should also call out in their documentation that react-antive polyfills are required to be added by their consumers when using react-native environments.