modulus add-command

Scaffolds a CQRS command with its handler and FluentValidation validator inside a module's Application layer. Commands represent intent to change state and are dispatched through the Modulus mediator pipeline.

Synopsis

modulus add-command <command-name> [options]

Arguments

Argument	Description
<command-name>	PascalCase name for the command (e.g., CreateProduct, PlaceOrder).

Options

Option	Description	Default
--module, -m <name>	(Required) Target module where the command will be created.	--
--solution, -s <path>	Path to the .slnx solution file.	Auto-discovered
--result-type, -r <type>	Return type wrapped in Result<T>. Omit for a void Result (commands that return no value). Accepts built-in aliases, BCL types, fully-qualified names, nullable (Guid?), arrays (int[], int[,]), and generic types (List<Guid>, Dictionary<string, decimal>, arbitrarily nested).	Void Result
--dry-run	Print the files that would be created without writing anything.	Disabled

Generated Output

Running modulus add-command CreateProduct --module Catalog --result-type Guid generates four files -- the command record, handler, and validator under src/Catalog.Application/Commands/CreateProduct/, plus a starter unit test. The record and classes are named exactly after the command (no Command suffix is appended):

Command record

src/Modules/Catalog/src/Catalog.Application/Commands/CreateProduct/CreateProduct.cs

using Modulus.Mediator.Abstractions;

namespace EShop.Catalog.Application.Commands.CreateProduct;

public sealed record CreateProduct : ICommand<Guid>;

Handler class

src/Modules/Catalog/src/Catalog.Application/Commands/CreateProduct/CreateProductHandler.cs

using Modulus.Mediator.Abstractions;

namespace EShop.Catalog.Application.Commands.CreateProduct;

public sealed class CreateProductHandler : ICommandHandler<CreateProduct, Guid>
{
    public Task<Result<Guid>> Handle(CreateProduct command, CancellationToken cancellationToken = default)
    {
        // TODO: Implement command logic
        throw new NotImplementedException();
    }
}

Validator class

src/Modules/Catalog/src/Catalog.Application/Commands/CreateProduct/CreateProductValidator.cs

using FluentValidation;

namespace EShop.Catalog.Application.Commands.CreateProduct;

public sealed class CreateProductValidator : AbstractValidator<CreateProduct>
{
    public CreateProductValidator()
    {
        // TODO: Add validation rules
    }
}

Unit test

src/Modules/Catalog/tests/Catalog.Tests.Unit/Commands/CreateProductHandlerTests.cs -- a starter test that constructs the handler directly. Both the handler and the validator are auto-registered by the source-generated AddModulusHandlers().

When --result-type is omitted, the command implements ICommand (no generic parameter) and the handler returns Result instead of Result<T> (with a Result.Success() placeholder body instead of NotImplementedException).

Examples

Create a command that returns a Guid:

modulus add-command CreateProduct --module Catalog --result-type Guid

Create a void command (no return value):

modulus add-command DeleteProduct --module Catalog

Create a command that returns a custom type:

modulus add-command PlaceOrder --module Orders --result-type OrderConfirmation

Create a command that returns a generic collection type:

modulus add-command ImportProducts --module Catalog --result-type "List<Guid>"

Preview the files that would be created without writing anything:

modulus add-command CreateProduct --module Catalog --result-type Guid --dry-run

See Also

• modulus add-query -- Scaffold read-side queries
• modulus add-endpoint -- Wire commands to HTTP endpoints
• Commands & Queries -- How the mediator dispatches commands
• Pipeline Behaviors -- Validation, logging, and other cross-cutting concerns