engine: graph: Allow send/recv to work with autogrouped resources

We've previously not received a value from within an autogrouped
resource. It turns out this would be quite useful, and so this patch
implements the additional plumbing and testing so that this works!

Testing that an autogrouped resource can still send values has not been
done at this time.

engine/graph/actions.go

@@ -112,21 +112,35 @@ func (obj *Engine) Process(ctx context.Context, vertex pgraph.Vertex) error {
 
 	// sendrecv!
 	// connect any senders to receivers and detect if values changed
+	// this actually checks and sends into resource trees recursively...
 	if res, ok := vertex.(engine.RecvableRes); ok {
 		if updated, err := obj.SendRecv(res); err != nil {
 			return errwrap.Wrapf(err, "could not SendRecv")
 		} else if len(updated) > 0 {
-			for _, changed := range updated {
-				if changed { // at least one was updated
-					// invalidate cache, mark as dirty
-					obj.state[vertex].tuid.StopTimer()
-					obj.state[vertex].isStateOK = false
-					break
+			for r, m := range updated { // map[engine.RecvableRes]map[string]bool
+				v, ok := r.(pgraph.Vertex)
+				if !ok {
+					continue
+				}
+				_, stateExists := obj.state[v] // autogrouped children probably don't have a state
+				if !stateExists {
+					continue
+				}
+				for _, changed := range m {
+					if !changed {
+						continue
+					}
+					// if changed == true, at least one was updated
+					// invalidate cache, mark as dirty
+					obj.state[v].tuid.StopTimer()
+					obj.state[v].isStateOK = false
+					//break // we might have more vertices now
+				}
+
+				// re-validate after we change any values
+				if err := engine.Validate(r); err != nil {
+					return errwrap.Wrapf(err, "failed Validate after SendRecv")
 				}
-			}
-			// re-validate after we change any values
-			if err := engine.Validate(res); err != nil {
-				return errwrap.Wrapf(err, "failed Validate after SendRecv")
 			}
 		}
 	}