/// <summary>
/// Save changes to the <see cref="DbContext"/> asynchronously.
/// </summary>
/// <typeparam name="TSource">The type of the value.</typeparam>
/// <param name="observable">The parent observable.</param>
/// <returns>An instance of <see cref="IProviderObservable{TSource}"/>.</returns>
public static IProviderObservable <TSource> SaveChangesAsync <TSource>(
this IProviderObservable <TSource> observable)
where TSource : class =>
observable.WithDbContextAsync(async(source, context) => await context.SaveChangesAsync())
.Catch((DbUpdateConcurrencyException exception) =>
Observable.Throw <TSource>(
new ConflictException(exception), observable.ServiceProvider));
/// <summary>
/// Perform an async action with the <see cref="EntityEntry{TEntity}"/>
/// of the received value.
/// </summary>
/// <typeparam name="TSource">The type of the value.</typeparam>
/// <param name="observable">The parent observable.</param>
/// <param name="action">The action to be performed.</param>
/// <returns>An instance of <see cref="IProviderObservable{TSource}"/>.</returns>
public static IProviderObservable <TSource> WithEntityEntryAsync <TSource>(
this IProviderObservable <TSource> observable, Func <EntityEntry <TSource>, Task> action)
where TSource : class =>
observable.WithDbContextAsync(async(source, context) =>
{
var entityEntry = context.Entry(source);
await action(entityEntry);
});
