From Discord: Transforming POJO with BigInt Keys to ReadonlyMap: Type Issue Solutions about effect HOT 1 CLOSED

export const EntriesFromRecord = <AK, KR, AV, IV, VR>(
  key: S.Schema<AK, string, KR>,
  value: S.Schema<AV, IV, VR>
): S.Schema<ReadonlyArray<readonly [AK, AV]>, {
  readonly [x: string]: IV
}, KR | VR> => {
  const from = S.Record(S.encodedSchema(key), value)
  const to = S.Array(S.Tuple(key, S.typeSchema(value)))
  return S.transform(from, to, {
    decode: Object.entries,
    encode: Object.fromEntries
  }).annotations({ description: `EntriesFromRecord<${key}, ${value}>` })
}

export const MapFromRecord = <AK, KR, AV, IV, VR>(
  key: S.Schema<AK, string, KR>,
  value: S.Schema<AV, IV, VR>
): S.Schema<Map<AK, AV>, Record<string, IV>, KR | VR> =>
  S.compose(
    EntriesFromRecord(key, value),
    S.Map({ key: S.typeSchema(key), value: S.typeSchema(value) })
  ).annotations({ description: `MapFromRecord<${key}, ${value}>` })