module: fix main lookup regression from #18728

[guybedford]

There was a minor regression in #18728 in the package.json main resolution code path.

This includes a test and a fix, hopefully these sort of slips will become harder as the test coverage on the modules work increases.

@bnoordhuis one of the slips here was on the enum booleans being checked as booleans. I considered making them extend boolean, but I assumed the intention is that usage should always be explicit with these, although it's a shame this can't be caught by the compiler at all.

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• tests and/or benchmarks are included
• commit message follows commit guidelines

Affected core subsystem(s)

modules

[benjamingr]

This can be fast tracked IMO

[benjamingr]

Also, that's weird @guybedford - it shouldn't be possible as far as I know :O http://coliru.stacked-crooked.com/a/efc7c335a197e56d

[jdalton]

@guybedford What was the regression?

[guybedford]

@jdalton the process of applying the package.json main stopped working.

@benjamingr that is really odd then that there was not even a compiler warning, and seems like it could be a problem!

Since we don't have compiler warnings for these cases, do you think I should just extend bool for these enums and switch their parity so they can be treated as booleans without breaking? Just thinking of maintainability here.

[guybedford]

CI: https://ci.nodejs.org/job/node-test-pull-request/13212/

[BridgeAR]

Landed in 7748865 🎉

[MylesBorins]

this should be backported with #18728