planforge-new-service

name	planforge-new-service
description	Scaffold a new service class with interface, DI registration, structured logging, input validation, and CancellationToken support.
metadata	{"author":"plan-forge","source":".github/prompts/new-service.prompt.md"}

---

description: "Scaffold a new service class with interface, DI registration, structured logging, input validation, and CancellationToken support." agent: "agent" tools: [read, edit, search]

Create New Service

Scaffold a service layer class following the strict layered architecture.

Required Pattern

Interface (I{EntityName}Service.cs)

public interface I{EntityName}Service
{
    Task<{EntityName}Dto> GetByIdAsync(Guid id, CancellationToken ct = default);
    Task<IEnumerable<{EntityName}Dto>> GetAllAsync(CancellationToken ct = default);
    Task<{EntityName}Dto> CreateAsync(Create{EntityName}Request request, CancellationToken ct = default);
    Task<bool> UpdateAsync(Guid id, Update{EntityName}Request request, CancellationToken ct = default);
    Task<bool> DeleteAsync(Guid id, CancellationToken ct = default);
}

Implementation ({EntityName}Service.cs)

public sealed partial class {EntityName}Service(
    I{EntityName}Repository repository,
    ILogger<{EntityName}Service> logger) : I{EntityName}Service
{
    [LoggerMessage(Level = LogLevel.Information, Message = "Creating {EntityName} — {Name}")]
    partial void LogCreating(string name);

    public async Task<{EntityName}Dto> CreateAsync(Create{EntityName}Request request, CancellationToken ct = default)
    {
        ArgumentNullException.ThrowIfNull(request);
        LogCreating(request.Name);
        // Validation, business rules, then delegate to repository
        return await repository.InsertAsync(request, ct);
    }
}

Rules

• ALL business logic lives in the service layer — not controllers, not repositories
• Use ArgumentNullException.ThrowIfNull() for required parameters
• Use typed exceptions: ValidationException, NotFoundException, ConflictException
• sealed partial class for source-generated logging
• CancellationToken on every async method
• Register as Scoped in DI: builder.Services.AddScoped<I{EntityName}Service, {EntityName}Service>();

Reference Files

• Architecture principles
• Error handling