# LS2005: Handler Name Lacks Its Command or Query Suffix

## Intent

LS2005 is a compiler check that reports a command or query handler, the type that runs a use case, whose name does not state which of the two it runs, so the model builder cannot tell a write from a read by its file name. This page states what the rule reports, where the error sits, and how to complete the handler name.

## Reference

### What the Rule Enforces

LS2005 enforces [Use architectural suffixes](https://litespec.dev/2.0.0/workspace/naming.md#use-architectural-suffixes) (`litespec/workspace/naming#use-architectural-suffixes`). It runs in Application and Infrastructure. Its category is `LiteSpec.Layers`. It reports an error and is enabled by default, as the [Analyzers overview](https://litespec.dev/2.0.0/analyzers/README.md) describes.

### What the Rule Reports

The rule reports a class that implements an interface named `ICommandHandler` unless its name ends in `CommandHandler`, and a class that implements an interface named `IQueryHandler` unless its name ends in `QueryHandler`. The diagnostic sits on the type name, and its message names the contract and the required suffix.

### Failing Example

```csharp
internal sealed class PlaceOrderUseCase : ICommandHandler<PlaceOrderCommand, int>
{
}
```

### Passing Example

```csharp
internal sealed class PlaceOrderCommandHandler : ICommandHandler<PlaceOrderCommand, int>
{
}
```

### How to Fix

End the class name in `CommandHandler` for a command and in `QueryHandler` for a query, keeping the use-case prefix the file name carries.

## Notes

### What the Rule Ignores

The rule does not report a class that implements neither contract, even when its name ends in `Handler`, and it does not report interfaces. It does not run in Domain, Application.Abstractions, or WebApi.