Releases

1. ▸▾2.1.115 May 2026

   new Release with many new features:

   new Release with many new features:

   • Some minor Fixes
   • Support for .NET 8 was added
   • Support for .NET 10 was added
   • Added missing async versions of FailIf methods
   • Added FailIf method overloads that allow to use value in error definition using Func<TValue, Error> error builder
   • Added ElseDo and ElseDoAsync methods
   • Added Else/ElseAsync overloads returning ErrorOr
   • Added Else/ElseAsync overloads returning ErrorOr
   • Added ToErrorOrAsync method
   • Added missing ErrorOrFactory.From methods
   • Added missing collection expression support
   • Added FromAsync and missing ToErrorOrAsync methods
   • Added ThenEnsure and ThenEnsureAsync methods
   • Added IsSuccess property to ErrorOr

   Open source →

   Additional notes

   Added

   • #94, #95 Added missing async versions of FailIf methods

     public async Task<ErrorOr<TValue>> FailIfAsync(Func<TValue, Task<bool>> onValue, Error error)
     

     public static async Task<ErrorOr<TValue>> FailIf<TValue>(
         this Task<ErrorOr<TValue>> errorOr,
         Func<TValue, bool> onValue,
         Error error)
     

     public static async Task<ErrorOr<TValue>> FailIfAsync<TValue>(
         this Task<ErrorOr<TValue>> errorOr,
         Func<TValue, Task<bool>> onValue,
         Error error)
     

   • #104 Support for .NET 8 was added

   • #109, #111 Added FailIf method overloads that allow to use value in error definition using Func<TValue, Error> error builder

     public ErrorOr<TValue> FailIf(Func<TValue, bool> onValue, Func<TValue, Error> errorBuilder)
     

     public async Task<ErrorOr<TValue>> FailIfAsync(Func<TValue, Task<bool>> onValue, Func<TValue, Task<Error>> errorBuilder)
     

     public static async Task<ErrorOr<TValue>> FailIf<TValue>(
         this Task<ErrorOr<TValue>> errorOr,
         Func<TValue, bool> onValue,
         Func<TValue, Error> errorBuilder)
     

     public static async Task<ErrorOr<TValue>> FailIfAsync<TValue>(
         this Task<ErrorOr<TValue>> errorOr,
         Func<TValue, Task<bool>> onValue,
         Func<TValue, Task<Error>> errorBuilder)
     

     Value can now be used to build the error:

     ErrorOr<int> result = errorOrInt
         .FailIf(num => num > 3, (num) => Error.Failure(description: $"{num} is greater than 3"));
     

   • #117 Added ElseDo and ElseDoAsync methods

     Actions returning no result can now be called when IsError is true.

     ErrorOr<string> foo = result
         .Else(errors => Error.Unexpected())
         .ElseDo(error => Console.WriteLine(error.FirstError.Description));
     

     ErrorOr<string> foo = await result
         .ElseDoAsync(HandleErrorAsync);
     

   • #122 Added ToErrorOrAsync method

     Values in Task can now be easily converted to ErrorOr.

     ErrorOr<int> result = await Task.FromResult(5).ToErrorOrAsync();
     

   • #129 Added missing ErrorOrFactory.From methods

     Now following calls from README.md are available

     ErrorOr<int> result = ErrorOrFactory.From<int>(Error.Unexpected());
     ErrorOr<int> result = ErrorOrFactory.From<int>([Error.Validation(), Error.Validation()]);
     

     Following call is now obsolete

     ErrorOr<int> errorOrPerson = ErrorOr<int>.From([Error.Validation(), Error.Validation()]);
     

   • #133 Added missing collection expression support

     Now following call from README.md is available

     ErrorOr<int> result = [Error.Validation(), Error.Validation()];
     

   • #134 Added FromAsync and missing ToErrorOrAsync methods

     Added support for FromAsync methods.

     public async Tak<ErrorOr<int>> GetValueAsync()
     {
         return await ErrorOrFactory.FromAsync(5);
     }
     

     public async Tak<ErrorOr<int>> SingleErrorToErrorOrAsync()
     {
         return await ErrorOrFactory.FromAsync<int>(Error.Unexpected());
     }
     

     public async Tak<ErrorOr<int>> MultipleErrorsToErrorOrAsync()
     {
         return await ErrorOrFactory.FromAsync([
             Error.Validation(description: "Invalid Name"),
             Error.Validation(description: "Invalid Last Name")
         ]);
     }
     

     Added support for ToErrorOrAsync methods from errors:

     Task<Error> errorTask = Task.FromResult(Error.Validation());
     ErrorOr<int> result = errorTask.ToErrorOrAsync<int>();
     

     List<Error> errors = [Error.Unauthorized(), Error.Validation()];
     Task<List<Error>> errorsTask = Task.FromResult(errors);
     ErrorOr<int> result = await errorsTask.ToErrorOrAsync<int>();
     

   • #149 Added Else/ElseAsync overloads returning ErrorOr

   • #152 Added ThenEnsure and ThenEnsureAsync methods.

     They are similar to ThenDo and ThenDoAsync, but they receive a function that can return errors. If no errors are returned, the original value is preserved and the ensure function's success value is ignored.

   • #159 Added IsSuccess property to ErrorOr

   • #158 Added support for serialization via IErrorOr interface without direct access to Value property. The IRecordable base interface provides a way to obtain a serialized representation of the current state.

     void Log(IErrorOr result)
     {
         Console.WriteLine(result.GetRecording(serializer));
     }
     

     IRecordingSerializer<TOutput> interface can be implemented to provide concrete serialization strategy, for exaple JSON serialization:

     using System.Text.Json;
     using System.Text.Json.Serialization;
     using ErrorOr;
     
     public class SystemTextJsonRecordingSerializer : IRecordingSerializer<string>
     {
         private static readonly JsonSerializerOptions JsonOptions = new()
         {
             WriteIndented = true,
             Converters = { new JsonStringEnumConverter() },
             DefaultIgnoreCondition = JsonIgnoreCondition.Never,
         };
     
         public string SerializeValue<TValue>(TValue value)
             => JsonSerializer.Serialize(value, JsonOptions);
     
         public string SerializeErrors(List<Error> errors)
             => JsonSerializer.Serialize(errors, JsonOptions);
     }
     

   • #179 Support for .NET 10 was added

   Fixed

   • #85, #97 ErrorOr turned into Value Object by reimplementing Equals and GetHashCode methods

     New dependency was introduced to Microsoft.Bcl.HashCode and development dependency was introduced to Nullable

   • #178 Initializing ErrorOr<T> with empty or null error collection results with unexpected error.

   Optimized

   • #98, #99 Memory consumption optimized by moving static empty errors lists from generic struct into non-generic class

   Refactored

   • #154 Modernized NuGet publish workflow