Judge the delivery-before-check order from the step records, not a poll: at capacity 1 the check starts the instant the delivery ends (R4g, issue 1887)

modules/mesh-build-go/cmd/mesh-build-go/asks_integration_test.go

@@ -16,6 +16,9 @@ import (
 	"git.novox.be/novox/mesh-sdk/go/testbus"
 )
 
+// checkCommit is the commit the check ask fetches, apart from the delivery ask's, so the fetch order names which ran first.
+const checkCommit = "89abcdef0123456789abcdef0123456789abcdef"
+
 // 1887/AC-order, 1887/AC-pull against the real bus: a check ask published before a delivery ask runs after it, and at
 // capacity 1 the second waits in the stream until the first ends.
 //
@@ -23,6 +26,10 @@ import (
 // build seat's stream and its fixed workers (SEAT_NODE_BUILD_GO and its workers) and deletes the stream at its end, so
 // anything else on that bus, a puller or a leftover consumer, could hold or take its delivery ask and let the check
 // ask run first. It starts from testbus (mesh-sdk, novox/hq ADR 0495 clause 5): a bus for this test alone, gone after it.
+//
+// **The order is read from the record.** At capacity 1 the puller starts the check the instant the delivery ask's step
+// ends, well before any poll, so "the check key holds a state" is true on correct behaviour (issue 1887). The test
+// waits for both asks to end and compares the step records' own Started and Ended times, and the fetch order by commit.
 func TestTheModuleTakesADeliveryAskBeforeAnEarlierCheck(t *testing.T) {
 	nc, err := nats.Connect(testbus.URL(t))
 	if err != nil {
@@ -41,6 +48,7 @@ func TestTheModuleTakesADeliveryAskBeforeAnEarlierCheck(t *testing.T) {
 	t.Cleanup(func() { _ = js.DeleteStream(context.Background(), "SEAT_NODE_BUILD_GO") })
 	check := deliveryAsk()
 	check.Kind = delivery.AskCheck
+	check.Build.Fetch["commit"] = checkCommit
 	first := deliveryAsk()
 	for _, a := range []delivery.StepAsk{check, first} {
 		raw, _ := delivery.EncodeStepAsk(a)
@@ -69,30 +77,36 @@ func TestTheModuleTakesADeliveryAskBeforeAnEarlierCheck(t *testing.T) {
 	p := m.Puller(steps, &buildstep.JetStreamAsks{JS: js, Language: delivery.AskGo})
 	p.PullWait = 200 * time.Millisecond
 	go p.Pull(ctx)
-	for _, a := range []delivery.StepAsk{first, check} {
-		key, _ := delivery.AskStepKey("ace", a.ID)
-		for deadline := time.Now().Add(10 * time.Second); ; time.Sleep(10 * time.Millisecond) {
-			states.mu.Lock()
-			v := states.steps[key]
-			states.mu.Unlock()
-			if len(v) > 0 && v[len(v)-1].State != delivery.StepRunning {
-				break
-			}
-			if time.Now().After(deadline) {
-				t.Fatalf("the ask %s (%s) never ended", a.ID, a.Kind)
-			}
-		}
+	var ran map[string][]delivery.Step
+	for deadline := time.Now().Add(10 * time.Second); ; time.Sleep(10 * time.Millisecond) {
+		ran = map[string][]delivery.Step{}
+		ended := 0
 		states.mu.Lock()
-		checkKey, _ := delivery.AskStepKey("ace", check.ID)
-		if a.ID == first.ID && len(states.steps[checkKey]) > 0 {
-			states.mu.Unlock()
-			t.Fatal("the check ask started before the delivery ask ended at capacity 1")
+		for _, a := range []delivery.StepAsk{first, check} {
+			key, _ := delivery.AskStepKey("ace", a.ID)
+			v := append([]delivery.Step(nil), states.steps[key]...)
+			ran[a.ID] = v
+			if len(v) > 0 && v[len(v)-1].State != delivery.StepRunning {
+				ended++
+			}
 		}
 		states.mu.Unlock()
+		if ended == 2 {
+			break
+		}
+		if time.Now().After(deadline) {
+			t.Fatalf("the asks never both ended: %v", ran)
+		}
+	}
+	// The check's step may start the moment the delivery's ends, so the order is read from the records' own times.
+	deliveryEnded := ran[first.ID][len(ran[first.ID])-1].Ended
+	checkStarted := ran[check.ID][0].Started
+	if checkStarted.Before(deliveryEnded) {
+		t.Fatalf("the check ask started at %v, before the delivery ask ended at %v at capacity 1", checkStarted, deliveryEnded)
 	}
 	mu.Lock()
 	defer mu.Unlock()
-	if len(order) != 2 {
-		t.Fatalf("fetched %v", order)
+	if len(order) != 2 || order[0] != askCommit || order[1] != checkCommit {
+		t.Fatalf("fetched %v, want the delivery ask's commit %s first, then the check's %s", order, askCommit, checkCommit)
 	}
 }