improved mem & cpu consumption

delivery_test.go

@@ -0,0 +1,41 @@
+package gubgub
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestSequentialDelivery(t *testing.T) {
+	const testMsg = 9786
+
+	feedback := make([]int, 0, 3)
+
+	subscribers := []Subscriber[int]{
+		func(i int) bool {
+			assert.Equalf(t, testMsg, i, "expected %d but got %d", testMsg, i)
+			feedback = append(feedback, 1)
+			return true
+		},
+		func(i int) bool {
+			assert.Equalf(t, testMsg, i, "expected %d but got %d", testMsg, i)
+			feedback = append(feedback, 2)
+			return false
+		},
+		func(i int) bool {
+			assert.Equalf(t, testMsg, i, "expected %d but got %d", testMsg, i)
+			feedback = append(feedback, 3)
+			return true
+		},
+	}
+
+	nextSubscribers := sequentialDelivery(testMsg, subscribers)
+
+	assert.Len(t, nextSubscribers, len(subscribers)-1, "expected to have one less subscriber")
+	assert.Len(t, feedback, 3, "one or more subscriber was not called")
+
+	finalSubscribers := sequentialDelivery(testMsg, nextSubscribers)
+
+	assert.Len(t, finalSubscribers, len(nextSubscribers), "expected to have the same subscribers")
+	assert.Len(t, feedback, 5, "one or more subscriber was not called")
+}