more

pkg/actor/simple_grain_pool.go

@@ -371,13 +371,15 @@ func (p *SimpleGrainPool[V]) getOrClaimGrain(id uint64) (Grain[V], error) {
 // var ErrNotOwner = fmt.Errorf("not owner")
 
 // Apply applies a mutation to a grain.
-func (p *SimpleGrainPool[V]) Apply(id uint64, mutation ...proto.Message) (*V, error) {
+func (p *SimpleGrainPool[V]) Apply(id uint64, mutation ...proto.Message) (*MutationResult[*V], error) {
 	grain, err := p.getOrClaimGrain(id)
 	if err != nil {
 		return nil, err
 	}
-	if applyErr := p.mutationRegistry.Apply(grain, mutation...); applyErr != nil {
-		return nil, applyErr
+
+	mutations, err := p.mutationRegistry.Apply(grain, mutation...)
+	if err != nil {
+		return nil, err
 	}
 	if p.storage != nil {
 		go func() {
@@ -386,7 +388,14 @@ func (p *SimpleGrainPool[V]) Apply(id uint64, mutation ...proto.Message) (*V, er
 			}
 		}()
 	}
-	return grain.GetCurrentState()
+	result, err := grain.GetCurrentState()
+	if err != nil {
+		return nil, err
+	}
+	return &MutationResult[*V]{
+		Result:    result,
+		Mutations: mutations,
+	}, nil
 }
 
 // Get returns the current state of a grain.