public static IAsyncResult <T, TError> ToAsyncResult <T, TError>(
this IAsyncMaybe <T> source,
Func <TError> errorSelector
)
{
if (source is null)
{
throw new ArgumentNullException(nameof(source));
}
if (errorSelector is null)
{
throw new ArgumentNullException(nameof(errorSelector));
}
async Task <IResult <T, TError> > Run(
IAsyncMaybe <T> asyncMaybe,
Func <TError> func
)
{
if (await asyncMaybe.HasValue.ConfigureAwait(false))
{
return(ErrorHandling.Result.Value <T, TError>(asyncMaybe.Value));
}
return(ErrorHandling.Result.Error <T, TError>(func()));
}
return(Run(source, errorSelector).ToAsyncResult());
}
/// <summary>
/// Returns a <see cref="IMaybe{T}" /> when awaited.
/// </summary>
/// <param name="source">
/// The <see cref="IMaybe{T}" />.
/// </param>
/// <typeparam name="T">
/// of <see cref="IMaybe{T}" />.
/// The <typeparamref name="T" />
/// </typeparam>
/// <returns></returns>
public static TaskAwaiter <IMaybe <T> > GetAwaiter <T>(this IAsyncMaybe <T> source) =>
source is null
? throw new ArgumentNullException(nameof(source))
private static async Task <IMaybe <T> > Mapper <T>(IAsyncMaybe <T> source) =>
await source.HasValue.ConfigureAwait(false)
? ErrorHandling.Maybe.Value(source.Value)
: ErrorHandling.Maybe.None <T>();
public Task Awaiting_Null_Throws()
{
IAsyncMaybe <string> maybe = null;
return(Assert.ThrowsAsync <ArgumentNullException>(async() => { await maybe; }));
}
