Run the served rotation's verb on the bus chain the controller keeps, as its child process does (issue 1945)

cmd/mesh-controller/composed_served_integration_test.go

@@ -460,6 +460,9 @@ func TestServedARotationRewritesOnlyTheCompositionsThatUseIt(t *testing.T) {
 	before := map[string]map[string]uint64{"anchor": m.revisions(t, "anchor"), "laptop": m.revisions(t, "laptop")}
 	holders, _ := m.open.inventory.HoldersOf(t.Context(), "postgres-database", "")
 	var waited uint64
+	// The verb runs here as its child process runs it: its inventory takes the chain from the bus the served controller keeps it
+	// on (the registrations and assignments are there), not the one in memory the fixture's store was made with.
+	inventory.OnTheBusChainForTest(t)
 	said, err := capturedOutput(func() error {
 		if err := rotateCommand(t.Context(), []string{"postgres-database"}); err != nil {
 			return err

internal/inventory/fortest.go

@@ -208,3 +208,11 @@ func (i *Inventory) PlanValuesForTest(t *testing.T) map[string][]byte {
 	}
 	return out
 }
+
+// OnTheBusChainForTest makes an inventory opened from now on on the test's store take the chain from its opener (the bus), not
+// the chain in memory the test made for the store: for a test that runs a verb in this process as the controller's child
+// process runs it, over the bus the serving controller keeps the chain on.
+func OnTheBusChainForTest(t *testing.T) {
+	t.Helper()
+	testChains.Delete(os.Getenv(store.Variable(Name)))
+}