Bump safe deps

[zemccartney]

• Upgrades immer (matching strange-middle-end bump forthcoming)
• Replaces deprecated eslint loader with new eslint webpack plugin
• -vvvv discussion about webpack upgrading issues below; TLDR I think upgrading is safe; does anyone else agree? or did i goof? 🎩 🍷 🐸

Updates on the blocked dependency upgrades — webpack-5-related and history — as discussed in the prior 2 months (Feb/Bri and Jan/Bill)

history

Still blocked, for a couple of reasons:

• Refer to Bri's writeup on the breaking changes involved
• the upgrade is also blocked by react-router and therefore connected-react-router, as well, as both are incompatible with history v5, still depending on v4, which seems to have caused a good bit of confusion:
  • Doesn't work properly with "history" v5.0.0 supasate/connected-react-router#487
  • React router not working after upgrading to v 5 remix-run/history#804
  • [v5] Undocumented breaking changes remix-run/history#811

I'm not sure the source of these issues; I'm also not sure why React Training didn't upgrade its packages — e.g. react-router, react-router-dom — to use the new history version. But the v5 release of history notes this version of history "will serve as the foundation for the upcoming release of React Router version 6." So maybe we're looking at more sweeping upgrades to the react router ecosystem down the line and should hold off on upgrading history till those are complete?

webpack v5

During his stint, Bri wrote:

error-overlay-webpack-plugin upgrading to webpack 5 is still holding up upgrading the three webpack libraries.

Specifically, we can't perform the following upgrades:

• webpack: 4.x.x --> 5.x.x
• copy-webpack-plugin: ^6.0.3 --> 8.x.x
• html-webpack-plugin: 4.x.x --> 5.x.x

This is still the case, but I did some digging into this to see if anything had changed since Bri's work and found the following, random, questionably helpful things:

• In keeping with this comment, I locally performed the above 3 upgrades and was able to start the app; I threw an error in App.js, saw the error overlay as expected. I was able to build and serve (npm run serve) the app without any apparent issues (though I could easily be missing something)

• error-overlay-webpack-plugin lists webpack as a peer dependency, specifying version 4, but I'm unclear why. As far as I can tell, they do so because they depend on react-dev-utils(create-react-app's webpack utilities), which are in flux due to CRA progressing through their own webpack upgrade: Webpack 5 support overview facebook/create-react-app#9994

  • By in flux, I mean, react-dev-utils aren't given their own, dedicated section or checklist item on CRA's checklist on the above-linked issue, but issues have cropped up ad-hoc from userland (Webpack 5 support overview facebook/create-react-app#9994 (comment) and remove chalk from formatWebpackMessages facebook/create-react-app#10198) as react-dev-util dependents have experimented with upgrading to webpack 5 and run into problems. Which might explain why error-overlay-webpack-plugin didn't cause any issues on upgrading strangeluv's webpack usage? The parts of react-dev-utils that plugin uses might be webpack 5 compatible already. Very very much a guess on my part
  • remove chalk from formatWebpackMessages facebook/create-react-app#10198 this work actually addressed an issue in one of the utils that error-overlay-webpack-plugin depends on, which may have made it compatible with webpack 5, since error-overlay-webpack-plugin's dependency is set to bring in this change, a patch, automatically

• If I'm right about any of the above, then error-overlay-webpack-plugin might not actually need any upgrading. That is, react-dev-utils might be already webpack 5 compatible, which would mean no upgrades necessary (other than fixing the package's peerDependency on webpack v4)

  • There is an open PR to upgrade some dependencies on error-overlay-webpack-plugin: chore(dep): Upgrade react-dev-utils to support webpack5 (#67) gregberge/error-overlay-webpack-plugin#72 But you can see most of the work is to upgrade the example code, not the package itself. And the changes to the actual dependencies (root package.json) look to be incorrect (they remove react-error-overlay as a dependency, which definitely breaks the package)

So! All that said, do we feel ok about going ahead with the webpack 5 upgrades, perhaps dealing with some flux in local development due to CRA's ongoing webpack upgrading?

[wswoodruff]

Idk I guess it's easier to just wait til the community gets its act together w/ this webpack 5 fiasco

[wswoodruff]

Looks grood!