README.md

Namespace Generation Sample

This sample demonstrates how the DurableTask source generator places extension methods into the same namespace as the orchestrator/activity classes.

What it shows

When using the [DurableTask] attribute on classes in different namespaces, the source generator will:

1. Place extension methods (e.g., ScheduleNewApprovalOrchestratorInstanceAsync(), CallRegistrationActivityAsync()) into the same namespace as the task class
2. Keep the AddAllGeneratedTasks() registration method in the Microsoft.DurableTask namespace
3. Simplify type names within the same namespace (e.g., MyClass instead of MyNS.MyClass)

This results in cleaner IDE suggestions — you only see extension methods for tasks that are imported via using statements.

Project structure

• Tasks.cs - Defines an orchestrator in NamespaceGenerationSample.Approvals and an activity in NamespaceGenerationSample.Registrations
• Program.cs - Shows how to use the generated extension methods with explicit using statements

How to run

1. Start the DTS emulator:

   docker run --name durabletask-emulator -d -p 8080:8080 -e ASPNETCORE_URLS=http://+:8080 mcr.microsoft.com/dts/dts-emulator:latest

2. Set the connection string environment variable:

   export DURABLE_TASK_SCHEDULER_CONNECTION_STRING="Endpoint=http://localhost:8080;TaskHub=default;Authentication=None"

3. Run the sample:

   dotnet run

Generated code

The source generator produces code like this:

// Extension methods in the task's namespace
namespace NamespaceGenerationSample.Approvals
{
    public static class GeneratedDurableTaskExtensions
    {
        public static Task<string> ScheduleNewApprovalOrchestratorInstanceAsync(
            this IOrchestrationSubmitter client, string input, StartOrchestrationOptions? options = null) { ... }
        
        public static Task<string> CallApprovalOrchestratorAsync(
            this TaskOrchestrationContext context, string input, TaskOptions? options = null) { ... }
    }
}

namespace NamespaceGenerationSample.Registrations
{
    public static class GeneratedDurableTaskExtensions
    {
        public static Task<string> CallRegistrationActivityAsync(
            this TaskOrchestrationContext ctx, int input, TaskOptions? options = null) { ... }
    }
}

// Registration method stays in Microsoft.DurableTask
namespace Microsoft.DurableTask
{
    public static class GeneratedDurableTaskExtensions
    {
        internal static DurableTaskRegistry AddAllGeneratedTasks(this DurableTaskRegistry builder) { ... }
    }
}