Move react-devtools-core to optional peer dependency

[SimenB]

Fixes #491.

Should possibly wrap

ink/src/reconciler.ts

Lines 24 to 30 in 763db80

	// We need to conditionally perform devtools connection to avoid
	// accidentally breaking other third-party code.
	// See https://github.com/vadimdemedes/ink/issues/384
	if (process.env.DEV === 'true') {
	// eslint-disable-next-line import/no-unassigned-import
	require('./devtools');
	}

into a more specific error as well?

[vadimdemedes]

Should possibly wrap into a more specific error as well?

You mean something like this?

try {
	require('react-devtools-core');
} catch {
	throw new Error('React Devtools requires `react-devtools-core` dependency to be installed.');
}

[SimenB]

Yeah, makes sense to me. Or possibly just a console.warn? Unless process.env.DEV === 'true' is solely used for devtools and have no other purpose, then throwing a descriptive error seems fine 🙂

[vadimdemedes]

Yep, DEV environment variable is only used for devtools. However, I like the idea of just having console.warn, because technically nothing is broken, so there's no reason to crash the whole app.

Let's go with console.warn 👍 Could you extend the error message to:

Debugging with React Devtools requires `react-devtools-core` dependency to be installed.

$ npm install --save-dev react-devtools-core

[SimenB]

Seems fine?

[vadimdemedes]

Yes, thank you!