snapshot of https://github.com/ThreeDotsLabs/watermill.git (master, 2026-09-15; blobs > 131072B omitted)

message/router/middleware/circuit_breaker_test.go

@@ -0,0 +1,61 @@
+package middleware_test
+
+import (
+	"errors"
+	"testing"
+	"time"
+
+	"github.com/ThreeDotsLabs/watermill/message"
+	"github.com/ThreeDotsLabs/watermill/message/router/middleware"
+	"github.com/sony/gobreaker"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestCircuitBreaker(t *testing.T) {
+	t.Parallel()
+
+	count := 0
+	failing := true
+
+	h := middleware.NewCircuitBreaker(
+		gobreaker.Settings{
+			Name:    "test",
+			Timeout: time.Millisecond * 50,
+		},
+	).Middleware(func(msg *message.Message) (messages []*message.Message, e error) {
+		count++
+
+		if failing {
+			return nil, errors.New("test error")
+		}
+
+		return nil, nil
+	})
+
+	msg := message.NewMessage("1", nil)
+
+	// The first 6 calls should fail and increment the count
+	for i := 0; i < 6; i++ {
+		_, err := h(msg)
+		assert.Error(t, err)
+	}
+
+	assert.Equal(t, 6, count)
+
+	// The next calls should fail and not increment the count (the circuit breaker is open)
+	for i := 0; i < 4; i++ {
+		_, err := h(msg)
+		assert.Error(t, err)
+	}
+	assert.Equal(t, 6, count)
+
+	time.Sleep(time.Millisecond * 100)
+	failing = false
+
+	// After a timeout, the Circuit Breaker is closed again
+	for i := 0; i < 4; i++ {
+		_, err := h(msg)
+		assert.NoError(t, err)
+	}
+	assert.Equal(t, 10, count)
+}