internal/link/engineseat.go

@@ -13,6 +13,7 @@ import (
 	oc "git.novox.be/novox/mesh-contracts/operator-and-conversation/go/seats/operatorchannel"
 	stdio "git.novox.be/novox/mesh-sdk/go"
 	"git.novox.be/novox/mesh-sdk/go/catalogue"
+	"git.novox.be/novox/mesh-sdk/go/seatlist"
 	"github.com/nats-io/nats.go"
 	"github.com/nats-io/nats.go/micro"
 )
@@ -99,6 +100,22 @@ func AnswerEngineCall(handle EngineFunc, verb, node, subject string, body []byte
 	return say()
 }
 
+// ServedEngineSeat is the engine's seat as it serves it: the seat list's definition once the engine holds it, and the
+// bootstrapped definition before (novox/hq ADR 0636 §2: every reader holds the bootstrapped seats from its start). The
+// link serves the seat when it opens, before the node agent starts the reader of the list; read from the list alone, the
+// engine served no verb, so nobody answered manifest-reads and the assigner kept an engine's old statement (issue 1966).
+func ServedEngineSeat() catalogue.Seat {
+	if s, ok := catalogue.SeatNamed(EngineSeat); ok && len(s.Serves) > 0 {
+		return s
+	}
+	for _, s := range catalogue.SeatsFromDefinitions(seatlist.Bootstrapped()) {
+		if s.Name == EngineSeat {
+			return s
+		}
+	}
+	return catalogue.Seat{Name: EngineSeat}
+}
+
 // EngineSeats is a link that serves this node's seat. Optional, as Asked is.
 type EngineSeats interface {
 	ServeEngineSeat(EngineFunc)
@@ -118,7 +135,7 @@ func (l *natsLink) ServeEngineSeat(handle EngineFunc) {
 		return
 	}
 	apart := make(chan struct{}, apartAtOnce)
-	for _, v := range catalogue.EngineVerbs(EngineSeat) {
+	for _, v := range ServedEngineSeat().Serves {
 		verb := v.Name
 		answer := EngineAnswer(handle, verb, l.node, apart)
 		meta := EngineEndpointMetadata(v, l.node)

internal/link/seats_for_tests_test.go

@@ -1,6 +1,9 @@
 package link
 
 import (
+	"slices"
+	"testing"
+
 	"git.novox.be/novox/mesh-sdk/go/catalogue"
 	"git.novox.be/novox/mesh-sdk/go/seatlist/seatlisttest"
 )
@@ -8,3 +11,25 @@ import (
 // The seats the tests judge against are given to catalogue as the node-engine gives the ones it read from the bus
 // (novox/hq ADR 0635 §1); catalogue compiles none.
 func init() { catalogue.UseSeats(catalogue.SeatsFromDefinitions(seatlisttest.Definitions())) }
+
+// Before the engine holds a seat list it serves its seat's verbs from the bootstrapped definition (issue 1966: served from
+// the empty list, it answered no verb and the assigner kept an old statement).
+func TestServedEngineSeatBeforeTheList(t *testing.T) {
+	held := catalogue.Seats()
+	defer catalogue.UseSeats(held)
+	for _, tc := range []struct {
+		name  string
+		seats []catalogue.Seat
+	}{{"no list held", nil}, {"list held", held}} {
+		catalogue.UseSeats(tc.seats)
+		var names []string
+		for _, v := range ServedEngineSeat().Serves {
+			names = append(names, v.Name)
+		}
+		for _, want := range []string{ActManifestReads, ActComposition, ActHandOver} {
+			if !slices.Contains(names, want) {
+				t.Errorf("%s: the engine serves %v, without %s", tc.name, names, want)
+			}
+		}
+	}
+}