Make the return type of AccountClient.fetchMultiple consistent

[quellen-sol]

fetchMultiple currently returns (Object | null)[], but it should return the account type similarly to fetch and fetchNullable, which would be (T | null)[]

[vercel]

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[Henry-E]

Makes sense to me, fixes an inconsistency between the return types. Unless there was some reason for the difference of return types between fetch and fetchMultiple in the first place? Though it doesn't seem likely.

Probably will merge soon

[quellen-sol]

Makes sense to me, fixes an inconsistency between the return types. Unless there was some reason for the difference of return types between fetch and fetchMultiple in the first place? Though it doesn't seem likely.

Probably will merge soon

Was curious about this too, so I looked back in the history a bit and saw that when fetchMultiple was created in #761, T was equal to any at the time, hence no explicit typing on the return type
https://github.com/glacial-engineering/anchor/blob/2bd4bb349abde32b25ceef8c1a0833206109cb1e/ts/src/program/namespace/account.ts#L71

When more typing to AccountClient was introduced afterward, it appears that fetchMultiple was most likely just overlooked and not changed.
https://github.com/coral-xyz/anchor/pull/795/files#diff-0e2c48e520eafaabcd0d9de371c7d2e74f5bbb4eba766216bb24efb265c0e5c3R82

Also one thing to note: This resolves #1580 and #1521 can be closed

May also resolve #1465

[Henry-E]

Thanks very much for looking into that.

I can see almost the exact same PR was made here #1521 .