major refactor to accommodate feed

feed_test.go

@@ -0,0 +1,62 @@
+package gubgub
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestFeed_Topics(t *testing.T) {
+	const msgCount = 10
+
+	subscriberReady := make(chan struct{}, 1)
+	defer close(subscriberReady)
+
+	onSubscribe := WithOnSubscribe(func(count int) {
+		subscriberReady <- struct{}{}
+	})
+
+	testCases := []struct {
+		name  string
+		topic Topic[int]
+	}{
+		{
+			name:  "sync topic",
+			topic: NewSyncTopic[int](onSubscribe),
+		},
+		{
+			name:  "async topic",
+			topic: NewAsyncTopic[int](onSubscribe),
+		},
+	}
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			feedback := make(chan int)
+			go func() {
+				for i := range Feed(tc.topic, false) {
+					feedback <- i
+				}
+			}()
+
+			go func() {
+				<-subscriberReady
+				for i := range msgCount {
+					require.NoError(t, tc.topic.Publish(i))
+				}
+			}()
+
+			var counter int
+			timeout := testTimer(t, time.Second)
+			for counter < msgCount {
+				select {
+				case <-feedback:
+					counter++
+				case <-timeout.C:
+					t.Fatalf("expected %d feedback values by now but only got %d", msgCount, counter)
+				}
+			}
+		})
+	}
+
+}