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

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)))
+}