README.md

WorkflowGuard

WorkflowGuard is a .NET library that provides an easy-to-use mechanism for applying resilient policies to method executions. It works similar to Polly, but offers simplistic way to support retry, fallback, and circuit breaker policies, enabling developers to ensure their applications are more resilient to transient faults and outages.

Features

• Attribute-Based Configuration: Apply retry, fallback, and circuit breaker policies using custom attributes.
• Dynamic Proxies: Automatically intercept method calls to apply policies without modifying business logic.
• Seamless Integration: Integrates smoothly with ASP.NET Core dependency injection and minimal APIs.

Usage

Attribute-Based Example

1. Define your service interface and implementation:

   public interface IService
   {
       [WorkflowGuard(retryPolicy: "DefaultRetryPolicy", fallbackPolicy: "DefaultFallbackPolicy", circuitBreakerPolicy: "DefaultCircuitBreakerPolicy")]
       Task<Customer> GetCustomerAsync(int id);
   
       [WorkflowGuard(retryPolicy: "DefaultRetryPolicy", fallbackPolicy: "DefaultFallbackPolicy", circuitBreakerPolicy: "DefaultCircuitBreakerPolicy")]
       Task<Order> CreateOrderAsync(Order order);
   }
   
   public class Service : IService
   {
       public async Task<Customer> GetCustomerAsync(int id)
       {
           // Implementation
       }
   
       public async Task<Order> CreateOrderAsync(Order order)
       {
           // Implementation
       }
   }

2. Register your services and apply the AddWorkflowAttributes extension in your startup configuration:

   var builder = WebApplication.CreateBuilder(args);
   
   // Configure WorkflowGuard
   builder.Services.AddSingleton<IWorkflowGuard>(sp => new WorkflowGuard(
       new Dictionary<string, RetryPolicy>
       {
           ["DefaultRetryPolicy"] = new RetryPolicy(3, TimeSpan.FromSeconds(2))
       },
       new Dictionary<string, FallbackPolicy>
       {
           ["DefaultFallbackPolicy"] = new FallbackPolicy(() => Task.FromResult<object>(new { Message = "Fallback result" }))
       },
       new Dictionary<string, CircuitBreakerPolicy>
       {
           ["DefaultCircuitBreakerPolicy"] = new CircuitBreakerPolicy(3, TimeSpan.FromSeconds(30))
       }
   ));
   
   // Register your services
   builder.Services.AddSingleton<IService, Service>();
   
   // Apply workflow attributes
   builder.Services.AddWorkflowAttributes();
   
   var app = builder.Build();
   
   app.MapGet("/customer/{id}", async (int id, IService service) =>
   {
       var customer = await service.GetCustomerAsync(id);
       return Results.Ok(customer);
   });
   
   app.MapPost("/order", async (Order order, IService service) =>
   {
       var createdOrder = await service.CreateOrderAsync(order);
       return Results.Ok(createdOrder);
   });
   
   app.Run();

Direct Usage Example (without Attributes)

Manually apply policies using IWorkflowGuard in your API endpoints:

app.MapGet("/customer/{id}", async (int id, IService service, IWorkflowGuard workflowGuard) =>
{
    var customer = await workflowGuard.ExecuteAsync(
        () => service.GetCustomerAsync(id),
        "DefaultRetryPolicy",
        "DefaultFallbackPolicy",
        "DefaultCircuitBreakerPolicy"
    );
    return Results.Ok(customer);
});

app.MapPost("/order", async (Order order, IService service, IWorkflowGuard workflowGuard) =>
{
    var createdOrder = await workflowGuard.ExecuteAsync(
        () => service.CreateOrderAsync(order),
        "DefaultRetryPolicy",
        "DefaultFallbackPolicy",
        "DefaultCircuitBreakerPolicy"
    );
    return Results.Ok(createdOrder);
});

app.Run();

Installation

dotnet add package WorkflowGuard