Perhaps just mimic Array.from()?

[getify]

Two options... could Object.fromEntries() just add an optional second param function that's called for each entry?

Or just add Object.from() which shallow-iterates a whole object (like Object.assign() does) but then has the optional second param function?

[ljharb]

See tc39/proposal-object-from-entries#13 - it's not a clear-cut choice for what the second argument should be.

For the latter, would Object.from just be function (o, fn) { return Object.fromEntries(Object.entries(o).map(fn)); }?

[getify]

For the latter, would Object.from just be...

Yep, that makes sense to me.

[decompil3d]

Agreed. Furthermore, this sort of arcane mechanism is not nearly as clear as just having a direct way to call a map operation over an iterated collection.