optimize getFetchedAt.ts

[slecoustre]

When you have a call with many identifiers then the getFetchedAt took a lot of time.

[Kmaschta]

How many identifiers did you have that this reduce becomes a performance issue ? :o

[slecoustre]

@Kmaschta I had 1200 id and it was between 1 to 2s just for getFetchedAt. with this optimization this is almost instantaneous

[fzaninotto]

I made some perf tests and the difference is indeed abysmal. I'm surprised that array reduce is so slow. Anyway, thanks a lot for the patch!

[NikitaVlaznev]

May be it's not reduce's fault.
Accumulator was recreated on each iteration by {...acc}:

const newRecordsById = newRecords.reduce(
    (acc, record) => ({
        ...acc,
        [record.id]: record,
    }),
    {}
);

May be this could solve the problem (comma operator just returns the last value):

const newRecordsById = newRecords.reduce(
    (acc, record) => (
        acc[record.id] = record,
        acc
    ),
    {}
);