Missing peer dependency on `react-dom`

[pieh]

This package import some utilities from react-dom:

react-redux/src/utils/reactBatchedUpdates.js

Line 2 in 2297944

export { unstable_batchedUpdates } from 'react-dom'

But react-dom is not specified as dependency or peerDependency

react-redux/package.json

Lines 38 to 49 in 2297944

	"peerDependencies": {
	"react": "^16.8.3",
	"redux": "^2.0.0 || ^3.0.0 || ^4.0.0-0"
	},
	"dependencies": {
	"@babel/runtime": "^7.5.5",
	"hoist-non-react-statics": "^3.3.0",
	"invariant": "^2.2.4",
	"loose-envify": "^1.4.0",
	"prop-types": "^15.7.2",
	"react-is": "^16.9.0"
	},

This cause Cannot file module 'react-dom' errors when using it with Ink (react for cli/terminal).

Installing react-dom does fix the issue (bit weird to install it for terminal app, but what can you do :) ). If react-dom is being used, it should be either dependency (probably not the way here) or peerDependency so package managers warn about missing dependency before we run into issues like that.

Issue discovered in gatsbyjs/gatsby#18603

[timdorr]

See these PRs:

#1261
#1282
#1371
#1366

[pieh]

That's unfortunate :/ but also understandable. Too bad package.json doesn't have some way to conditionally declare dependencies.

Given amount if PRs and issues about this, what do you think about putting some context around that import in source code to guard against PRs and issues about this in the future? :)

In any case - thanks for quick response!

[markerikson]

Heh. Yeah, a "DON'T MESS WITH THIS!" comment might not be a bad idea :)

[timdorr]

Too bad package.json doesn't have some way to conditionally declare dependencies.

They do. It's peerDependenciesMeta and it's in all the latest package managers, but is too new to rely on (unlike browsers, we can't polyfill npm 😄).