Test the controller's seal under a silent vault, the bus machine's refusal and a served fact that says a setting (issues 1385, 1383, 1382)

cmd/mesh-controller/compose_input_credentials_integration_test.go

@@ -328,3 +328,27 @@ func TestTheAdaptersInputCarriesTheBuildsAndTheMachinesKey(t *testing.T) {
 		}
 	}
 }
+
+// The lead's answer 4: where the mesh holds no credential for any bus user, the machine that runs the bus is refused with
+// busUserList's words (the controller's composition refused it), the Input still builds, and another machine composes.
+func TestTheBusMachineIsRefusedWhereNoUserHasACredentialAndTheOthersCompose(t *testing.T) {
+	open, _ := aMeshWithSecrets(t)
+	ctx := t.Context()
+	bus := catalogue.Manifest{Module: "nats", Version: "1", BusUsers: "/etc/nats/users.conf",
+		Claims: []catalogue.Claim{{Name: "mesh-broker", Scope: catalogue.ScopeMesh}}}
+	register(t, open, bus)
+	register(t, open, aWebModule())
+	if _, err := assign(ctx, open, "anchor", "nats"); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := assign(ctx, open, "laptop", "web"); err != nil {
+		t.Fatal(err)
+	}
+	if _, _, err := composeQuestion(ctx, open, "anchor", compose.Foreseeing, false); err == nil ||
+		!strings.Contains(err.Error(), "not one user has a credential") {
+		t.Fatalf("the bus machine is composed: %v", err)
+	}
+	if _, _, err := composeQuestion(ctx, open, "laptop", compose.Foreseeing, false); err != nil {
+		t.Fatalf("a machine that does not run the bus is refused: %v", err)
+	}
+}