Cleanup and async helpers

Cleanup.SafeMethod

Pineapple.Common.Cleanup.SafeMethod runs an action and swallows any exception, returning a fluent object for follow-up actions. Use it in finally blocks and Dispose methods where a secondary failure must not mask the original one.

using static Pineapple.Common.Cleanup;

SafeMethod(() => File.Delete(tempPath))
    .OnSuccess(() => _logger.LogDebug("Temp file removed"))
    .OnFailure(() => _logger.LogWarning("Could not remove {Path}", tempPath))
    .Continue(connection.Close);

Method	Runs when
OnSuccess(action)	The previous action succeeded
OnFailure(action)	The previous action threw
Continue(action)	Always

Every follow-up is itself run safely.

SynchronizationContextScope

Temporarily replaces SynchronizationContext.Current, restoring the original on dispose. SuppressSynchronizationContextScope sets it to null.

using Pineapple.Threading;

using (new SuppressSynchronizationContextScope())
{
    // Continuations run on the thread pool, not the captured UI/request context.
    var result = LoadAsync().GetAwaiter().GetResult();
}

Pair with Preconditions.CheckIsNotOnSynchronizationContext() to assert that code runs without a context.

Immutable collection helpers

Pineapple.Extensions.ImmutableExtensions adds null-tolerant Append methods to IImmutableList<T> and IImmutableDictionary<TKey, TValue>:

IImmutableList<Order> list = null;
list = list.Append(order);            // creates the list if null
list = list.Append(moreOrders);

Dependency injection helpers

Pineapple.Extensions.ServiceCollectionExtensions adds services.IsConfigured<T>() (is a service of type T registered?) and services.Configure<T>() (register T as a singleton).

Questions about async helpers

How do I avoid deadlocks when blocking on async code in .NET?

Prefer async all the way. When you must block (for example in a legacy UI or ASP.NET handler), clear the SynchronizationContext first so continuations don’t try to resume on the blocked thread: using (new SuppressSynchronizationContextScope()) { task.GetAwaiter().GetResult(); }.