Make the rollout tests wait for the plan look to return before their cleanups restore what it reads, which raced (issue 1338)

cmd/mesh-controller/rollout_events_test.go

@@ -179,7 +179,7 @@ func TestARolloutAdvancesOnEventsAndAReplacedControllerResumesIt(t *testing.T) {
 	// The first controller. Its plan has tier 0 built and tier 1 not asked: nothing but the save asks anything.
 	first, stopFirst := context.WithCancel(ctx)
 	defer stopFirst()
-	startRolloutEvents(first, open, js)
+	waitFirst := startRolloutEvents(first, open, js)
 	built := time.Now().UTC()
 	p := inventory.Plan{ID: "plan-974", Repository: "novox/mesh-catalog", Branch: "main", Commit: "c2", Created: built,
 		State: inventory.PlanBuilding, Tiers: [][]string{{"a"}, {"b"}},
@@ -199,12 +199,15 @@ func TestARolloutAdvancesOnEventsAndAReplacedControllerResumesIt(t *testing.T) {
 
 	// The controller is replaced: its looks and its watcher end. anchor reports meanwhile, to nobody.
 	stopFirst()
+	waitFirst()
 	time.Sleep(300 * time.Millisecond)
 	reports("anchor")
 
 	second, stopSecond := context.WithCancel(ctx)
 	defer stopSecond()
-	startRolloutEvents(second, open, js)
+	waitSecond := startRolloutEvents(second, open, js)
+	// Ends with the test before the cleanups restore what the look reads, which run after it (issue 1338).
+	t.Cleanup(func() { stopSecond(); waitSecond() })
 	// Its first look finds anchor reported, so its key goes; laptop's stays, and is the new controller's to hear expire.
 	eventually(t, "the new controller's first look deletes the key of the machine that reported", func() bool {
 		h := heldKeys()
@@ -321,7 +324,7 @@ func TestAWalkLetGoByTheDeliverVerbIsAskedWithNoOtherEvent(t *testing.T) {
 	t.Cleanup(func() { inventory.PlanSaved = wasSaved })
 	started, stop := context.WithCancel(ctx)
 	defer stop()
-	startRolloutEvents(started, open, js)
+	wait := startRolloutEvents(started, open, js)
 	time.Sleep(500 * time.Millisecond) // the first look: the walk waits, and is asked nothing
 
 	// The verb as its child process runs it: the delivery command, whose saves are not the serving controller's.
@@ -333,6 +336,9 @@ func TestAWalkLetGoByTheDeliverVerbIsAskedWithNoOtherEvent(t *testing.T) {
 		return verbAnswer{}, deliveryCommand(ctx, []string{"go", waiting.ID, "--why", "its turn"})
 	}
 	t.Cleanup(func() { runTheVerb = wasRun })
+	// Registered after every variable cleanup above, so it runs before them (last in, first out): the look at the plans
+	// has returned when checkEvents, inventory.PlanSaved and runTheVerb are restored (issue 1338).
+	t.Cleanup(func() { stop(); wait() })
 	handlers, _, err := seatToolHandlers()
 	if err != nil {
 		t.Fatal(err)