fix: add sideEffects: false to react-error-overlay

[SimenB]

This allows us to leave the import in the code, and webpack will still tree shake it out.

Verified by grepping for startReportingRuntimeErrors in the resulting bundle.

Note that this is usage outside of react-dev-utils.

Without this change, I need to use require and not import, and stick my require inside of an environment check.

Docs: https://webpack.js.org/guides/tree-shaking/#mark-the-file-as-side-effect-free

[stale]

This pull request has been automatically marked as stale because it has not had any recent activity. It will be closed in 5 days if no further activity occurs.

[stale]

This pull request has been automatically closed because it has not had any recent activity. If you have a question or comment, please open a new issue. Thank you for your contribution!

[SimenB]

Why have a bot autoclose PRs that hasn't been acknowledged by the maintainers? Not the friendliest thing in the world (I personally don't really care, but it can be disheartening to beginners, methinks)

/cc @Timer mind taking a look at this?

[Timer]

Can you please confirm the bundle is byte-for-byte identical when this flag is enabled (well... disabled -- false) and the overlay is imported & used?

[SimenB]

What bundle do you refer to? An app built with CRA, or the built version of just the overlay?

[Timer]

The dev bundle.

[SimenB]

Yes, they're identical 🙂

$ yarn create react-app myapp
$ cd myapp
$ yarn start &
$ curl -s http://localhost:3000/static/js/bundle.js | md5c2e99be9db96e20f22b9bd578cc80fea
$ curl -s http://localhost:3000/static/js/0.chunk.js | md507e94a964f183f6edaee07cb113c1e03
$ curl -s http://localhost:3000/static/js/main.chunk.js | md509ec1827050bed667003a85530d36ac4
# Change package.json of error overlay, and restart server
$ curl -s http://localhost:3000/static/js/bundle.js | md5c2e99be9db96e20f22b9bd578cc80fea
$ curl -s http://localhost:3000/static/js/0.chunk.js | md507e94a964f183f6edaee07cb113c1e03
$ curl -s http://localhost:3000/static/js/main.chunk.js | md509ec1827050bed667003a85530d36ac4

[Timer]

can't get CI to pass, YOLO