Fix error-codes not updating correctly

[thymikee]

Fixes #10328

If I understand correctly, calls to require() in scripts context get cached into some kind of module map, similarly like in jest-haste-map (or maybe are hoisted to the top of module behind the scenes?). At least that's what I observe.

Because the cache isn't invalidated after performing fs.writeFileSync, existingErrorMap was always the same (despite inline require), resulting in codes.json file not being updated properly.

One way to fix this is through replacing require with fs.readFileSync and that's what this PR is about.

[thymikee]

cc @gaearon @trueadm who may have more context on this.

[gaearon]

Thanks, this is great! Can you please just leave the fix in without the codes change? We’ll update codes before the release.

[thymikee]

Sure, reverted codes :)