Combines AsyncValues for use with Riverpod

combine_async.dart

import 'package:hooks_riverpod/all.dart';
import 'package:tuple/tuple.dart';

AsyncValue<Tuple2<T, R>> combineAsync2<T, R>(
  AsyncValue<T> asyncOne,
  AsyncValue<R> asyncTwo,
) {
  if (asyncOne is AsyncError) {
    final error = asyncOne as AsyncError<T>;
    return AsyncError(error.error, error.stackTrace);
  } else if (asyncTwo is AsyncError) {
    final error = asyncTwo as AsyncError<R>;
    return AsyncError(error.error, error.stackTrace);
  } else if (asyncOne is AsyncLoading || asyncTwo is AsyncLoading) {
    return AsyncLoading();
  } else if (asyncOne is AsyncData && asyncTwo is AsyncData) {
    return AsyncData(Tuple2<T, R>(asyncOne.data.value, asyncTwo.data.value));
  } else {
    throw 'Unsupported case';
  }
}

AsyncValue<Tuple3<T, R, S>> combineAsync3<T, R, S>(
  AsyncValue<T> asyncOne,
  AsyncValue<R> asyncTwo,
  AsyncValue<S> asyncThree,
) {
  if (asyncOne is AsyncError) {
    final error = asyncOne as AsyncError<T>;
    return AsyncError(error.error, error.stackTrace);
  } else if (asyncTwo is AsyncError) {
    final error = asyncTwo as AsyncError<R>;
    return AsyncError(error.error, error.stackTrace);
  } else if (asyncThree is AsyncError) {
    final error = asyncThree as AsyncError<S>;
    return AsyncError(error.error, error.stackTrace);
  } else if (asyncOne is AsyncLoading ||
      asyncTwo is AsyncLoading ||
      asyncThree is AsyncLoading) {
    return AsyncLoading();
  } else if (asyncOne is AsyncData &&
      asyncTwo is AsyncData &&
      asyncThree is AsyncData) {
    return AsyncData(Tuple3<T, R, S>(
      asyncOne.data.value,
      asyncTwo.data.value,
      asyncThree.data.value,
    ));
  } else {
    throw 'Unsupported case';
  }
}

AsyncValue<Tuple4<T, R, S, Q>> combineAsync4<T, R, S, Q>(
  AsyncValue<T> asyncOne,
  AsyncValue<R> asyncTwo,
  AsyncValue<S> asyncThree,
  AsyncValue<Q> asyncFour,
) {
  if (asyncOne is AsyncError) {
    final error = asyncOne as AsyncError<T>;
    return AsyncError(error.error, error.stackTrace);
  } else if (asyncTwo is AsyncError) {
    final error = asyncTwo as AsyncError<R>;
    return AsyncError(error.error, error.stackTrace);
  } else if (asyncThree is AsyncError) {
    final error = asyncThree as AsyncError<S>;
    return AsyncError(error.error, error.stackTrace);
  } else if (asyncFour is AsyncError) {
    final error = asyncFour as AsyncError<Q>;
    return AsyncError(error.error, error.stackTrace);
  } else if (asyncOne is AsyncLoading ||
      asyncTwo is AsyncLoading ||
      asyncThree is AsyncLoading ||
      asyncFour is AsyncLoading) {
    return AsyncLoading();
  } else if (asyncOne is AsyncData &&
      asyncTwo is AsyncData &&
      asyncThree is AsyncData &&
      asyncFour is AsyncData) {
    return AsyncData(Tuple4<T, R, S, Q>(
      asyncOne.data.value,
      asyncTwo.data.value,
      asyncThree.data.value,
      asyncFour.data.value,
    ));
  } else {
    throw 'Unsupported case';
  }
}