Disallow IStatePulse Injection in IEffect

[mshimshon]

Summary

Introduce a Roslyn analyzer that generates a compile time error when a class implementing IEffect injects IStatePulse.

Problem

IStatePulse is designed to provide near zero boilerplate state change observation.
Its purpose is to simplify UI layer bindings where components need to react automatically to state updates.

IStatePulse is not intended to be used as a universal state access mechanism and must not be injected inside IEffect handlers.

Effects are ephemeral by design. When an effect handler executes, it already runs in response to a dispatch event and can access the latest state at runtime.

Creating a state pulse binding inside an effect introduces an unnecessary reactive dependency that contradicts the intended lifecycle of effects.

Architectural Intent

IStatePulse:

• designed for UI level state subscriptions
• built for long lived reactive bindings
• internally built on top of IStateAccessor<TState>

IEffect:

• designed to be short lived and execution scoped
• triggered by dispatch events
• should read state on demand

Because of this mismatch, using IStatePulse inside an effect introduces architectural misuse.

Correct Alternative

If an effect needs to read state, it must use IStateAccessor<TState>:

This provides direct access to the latest state without establishing a reactive subscription.

Example:

public class MyEffect : IEffect<MyAction>
{
    private readonly IStateAccessor<MyState> _state;

    public MyEffect(IStateAccessor<MyState> state)
    {
        _state = state;
    }

    public Task HandleAsync(MyAction action, IDisaptcher disaptcher)
    {
        var current = _state.Value;
        return Task.CompletedTask;
    }
}

Example That Should Trigger the Analyzer

public class MyEffect : IEffect<MyAction>
{
    private readonly IStatePulse _pulse;

    public MyEffect(IStatePulse pulse)
    {
        _pulse = pulse;
    }
}