internal/grpcsync: refactor test (#6427)

internal/grpcsync/pubsub_test.go

@@ -19,44 +19,26 @@
 package grpcsync
 
 import (
-	"fmt"
 	"sync"
 	"testing"
 	"time"
-
-	"github.com/google/go-cmp/cmp"
 )
 
 type testSubscriber struct {
-	mu      sync.Mutex
-	msgs    []int
-	onMsgCh chan struct{}
+	onMsgCh chan int
 }
 
 func newTestSubscriber(chSize int) *testSubscriber {
-	return &testSubscriber{onMsgCh: make(chan struct{}, chSize)}
+	return &testSubscriber{onMsgCh: make(chan int, chSize)}
 }
 
 func (ts *testSubscriber) OnMessage(msg interface{}) {
-	ts.mu.Lock()
-	defer ts.mu.Unlock()
-	ts.msgs = append(ts.msgs, msg.(int))
 	select {
-	case ts.onMsgCh <- struct{}{}:
+	case ts.onMsgCh <- msg.(int):
 	default:
 	}
 }
 
-func (ts *testSubscriber) receivedMsgs() []int {
-	ts.mu.Lock()
-	defer ts.mu.Unlock()
-
-	msgs := make([]int, len(ts.msgs))
-	copy(msgs, ts.msgs)
-
-	return msgs
-}
-
 func (s) TestPubSub_PublishNoMsg(t *testing.T) {
 	pubsub := NewPubSub()
 	defer pubsub.Stop()
@@ -66,7 +48,7 @@ func (s) TestPubSub_PublishNoMsg(t *testing.T) {
 
 	select {
 	case <-ts.onMsgCh:
-		t.Fatalf("Subscriber callback invoked when no message was published")
+		t.Fatal("Subscriber callback invoked when no message was published")
 	case <-time.After(defaultTestShortTimeout):
 	}
 }
@@ -78,7 +60,6 @@ func (s) TestPubSub_PublishMsgs_RegisterSubs_And_Stop(t *testing.T) {
 
 	ts1 := newTestSubscriber(numPublished)
 	pubsub.Subscribe(ts1)
-	wantMsgs1 := []int{}
 
 	var wg sync.WaitGroup
 	wg.Add(2)
@@ -86,43 +67,41 @@ func (s) TestPubSub_PublishMsgs_RegisterSubs_And_Stop(t *testing.T) {
 	go func() {
 		for i := 0; i < numPublished; i++ {
 			pubsub.Publish(i)
-			wantMsgs1 = append(wantMsgs1, i)
 		}
 		wg.Done()
 	}()
 
-	isTimeout := false
 	go func() {
+		defer wg.Done()
 		for i := 0; i < numPublished; i++ {
 			select {
-			case <-ts1.onMsgCh:
+			case m := <-ts1.onMsgCh:
+				if m != i {
+					t.Errorf("Received unexpected message: %q; want: %q", m, i)
+					return
+				}
 			case <-time.After(defaultTestTimeout):
-				isTimeout = true
+				t.Error("Timeout when expecting the onMessage() callback to be invoked")
+				return
 			}
 		}
-		wg.Done()
 	}()
-
 	wg.Wait()
-	if isTimeout {
-		t.Fatalf("Timeout when expecting the onMessage() callback to be invoked")
-	}
-	if gotMsgs1 := ts1.receivedMsgs(); !cmp.Equal(gotMsgs1, wantMsgs1) {
-		t.Fatalf("Received messages is %v, want %v", gotMsgs1, wantMsgs1)
+	if t.Failed() {
+		t.FailNow()
 	}
 
 	// Register another subscriber and ensure that it receives the last published message.
 	ts2 := newTestSubscriber(numPublished)
 	pubsub.Subscribe(ts2)
-	wantMsgs2 := wantMsgs1[len(wantMsgs1)-1:]
 
 	select {
-	case <-ts2.onMsgCh:
+	case m := <-ts2.onMsgCh:
+		if m != numPublished-1 {
+			t.Fatalf("Received unexpected message: %q; want: %q", m, numPublished-1)
+		}
 	case <-time.After(defaultTestShortTimeout):
-		t.Fatalf("Timeout when expecting the onMessage() callback to be invoked")
-	}
-	if gotMsgs2 := ts2.receivedMsgs(); !cmp.Equal(gotMsgs2, wantMsgs2) {
-		t.Fatalf("Received messages is %v, want %v", gotMsgs2, wantMsgs2)
+		t.Fatal("Timeout when expecting the onMessage() callback to be invoked")
 	}
 
 	wg.Add(3)
@@ -130,43 +109,43 @@ func (s) TestPubSub_PublishMsgs_RegisterSubs_And_Stop(t *testing.T) {
 	go func() {
 		for i := 0; i < numPublished; i++ {
 			pubsub.Publish(i)
-			wantMsgs1 = append(wantMsgs1, i)
-			wantMsgs2 = append(wantMsgs2, i)
-		}
-		wg.Done()
-	}()
-	errCh := make(chan error, 1)
-	go func() {
-		for i := 0; i < numPublished; i++ {
-			select {
-			case <-ts1.onMsgCh:
-			case <-time.After(defaultTestTimeout):
-				errCh <- fmt.Errorf("")
-			}
 		}
 		wg.Done()
 	}()
 	go func() {
+		defer wg.Done()
 		for i := 0; i < numPublished; i++ {
 			select {
-			case <-ts2.onMsgCh:
+			case m := <-ts1.onMsgCh:
+				if m != i {
+					t.Errorf("Received unexpected message: %q; want: %q", m, i)
+					return
+				}
 			case <-time.After(defaultTestTimeout):
-				errCh <- fmt.Errorf("")
+				t.Error("Timeout when expecting the onMessage() callback to be invoked")
+				return
+			}
+		}
+
+	}()
+	go func() {
+		defer wg.Done()
+		for i := 0; i < numPublished; i++ {
+			select {
+			case m := <-ts2.onMsgCh:
+				if m != i {
+					t.Errorf("Received unexpected message: %q; want: %q", m, i)
+					return
+				}
+			case <-time.After(defaultTestTimeout):
+				t.Error("Timeout when expecting the onMessage() callback to be invoked")
+				return
 			}
 		}
-		wg.Done()
 	}()
 	wg.Wait()
-	select {
-	case <-errCh:
-		t.Fatalf("Timeout when expecting the onMessage() callback to be invoked")
-	default:
-	}
-	if gotMsgs1 := ts1.receivedMsgs(); !cmp.Equal(gotMsgs1, wantMsgs1) {
-		t.Fatalf("Received messages is %v, want %v", gotMsgs1, wantMsgs1)
-	}
-	if gotMsgs2 := ts2.receivedMsgs(); !cmp.Equal(gotMsgs2, wantMsgs2) {
-		t.Fatalf("Received messages is %v, want %v", gotMsgs2, wantMsgs2)
+	if t.Failed() {
+		t.FailNow()
 	}
 
 	pubsub.Stop()
@@ -178,9 +157,9 @@ func (s) TestPubSub_PublishMsgs_RegisterSubs_And_Stop(t *testing.T) {
 	// pubsub has already closed.
 	select {
 	case <-ts1.onMsgCh:
-		t.Fatalf("The callback was invoked after pubsub being stopped")
+		t.Fatal("The callback was invoked after pubsub being stopped")
 	case <-ts2.onMsgCh:
-		t.Fatalf("The callback was invoked after pubsub being stopped")
+		t.Fatal("The callback was invoked after pubsub being stopped")
 	case <-time.After(defaultTestShortTimeout):
 	}
 }
@@ -197,15 +176,15 @@ func (s) TestPubSub_PublishMsgs_BeforeRegisterSub(t *testing.T) {
 	ts := newTestSubscriber(numPublished)
 	pubsub.Subscribe(ts)
 
-	wantMsgs := []int{numPublished - 1}
 	// Ensure that the subscriber callback is invoked with a previously
 	// published message.
 	select {
-	case <-ts.onMsgCh:
-		if gotMsgs := ts.receivedMsgs(); !cmp.Equal(gotMsgs, wantMsgs) {
-			t.Fatalf("Received messages is %v, want %v", gotMsgs, wantMsgs)
+	case d := <-ts.onMsgCh:
+		if d != numPublished-1 {
+			t.Fatalf("Unexpected message received: %q; %q", d, numPublished-1)
 		}
+
 	case <-time.After(defaultTestShortTimeout):
-		t.Fatalf("Timeout when expecting the onMessage() callback to be invoked")
+		t.Fatal("Timeout when expecting the onMessage() callback to be invoked")
 	}
 }