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

components/cqrs/event_bus_test.go

@@ -0,0 +1,168 @@
+package cqrs_test
+
+import (
+	"context"
+	"fmt"
+	"testing"
+
+	"github.com/ThreeDotsLabs/watermill/components/cqrs"
+	"github.com/pkg/errors"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestEventBusConfig_Validate(t *testing.T) {
+	testCases := []struct {
+		Name              string
+		ModifyValidConfig func(*cqrs.EventBusConfig)
+		ExpectedErr       error
+	}{
+		{
+			Name:              "valid_config",
+			ModifyValidConfig: nil,
+			ExpectedErr:       nil,
+		},
+		{
+			Name: "missing_GenerateEventPublishTopic",
+			ModifyValidConfig: func(config *cqrs.EventBusConfig) {
+				config.GeneratePublishTopic = nil
+			},
+			ExpectedErr: fmt.Errorf("missing GenerateHandlerTopic"),
+		},
+		{
+			Name: "missing_marshaler",
+			ModifyValidConfig: func(config *cqrs.EventBusConfig) {
+				config.Marshaler = nil
+			},
+			ExpectedErr: fmt.Errorf("missing Marshaler"),
+		},
+	}
+	for i := range testCases {
+		tc := testCases[i]
+
+		t.Run(tc.Name, func(t *testing.T) {
+			validConfig := cqrs.EventBusConfig{
+				GeneratePublishTopic: func(params cqrs.GenerateEventPublishTopicParams) (string, error) {
+					return "", nil
+				},
+				Marshaler: cqrs.JSONMarshaler{},
+			}
+
+			if tc.ModifyValidConfig != nil {
+				tc.ModifyValidConfig(&validConfig)
+			}
+
+			err := validConfig.Validate()
+			if tc.ExpectedErr == nil {
+				assert.NoError(t, err)
+			} else {
+				assert.EqualError(t, err, tc.ExpectedErr.Error())
+			}
+		})
+	}
+}
+
+func TestNewEventBus(t *testing.T) {
+	pub := newPublisherStub()
+	generateTopic := func(commandName string) string {
+		return ""
+	}
+	marshaler := cqrs.JSONMarshaler{}
+
+	cb, err := cqrs.NewEventBus(pub, generateTopic, marshaler)
+	assert.NotNil(t, cb)
+	assert.NoError(t, err)
+
+	cb, err = cqrs.NewEventBus(nil, generateTopic, marshaler)
+	assert.Nil(t, cb)
+	assert.Error(t, err)
+
+	cb, err = cqrs.NewEventBus(pub, nil, marshaler)
+	assert.Nil(t, cb)
+	assert.Error(t, err)
+
+	cb, err = cqrs.NewEventBus(pub, generateTopic, nil)
+	assert.Nil(t, cb)
+	assert.Error(t, err)
+}
+
+func TestEventBus_Send_ContextPropagation(t *testing.T) {
+	publisher := newPublisherStub()
+
+	eventBus, err := cqrs.NewEventBus(
+		publisher,
+		func(eventName string) string {
+			return "whatever"
+		},
+		cqrs.JSONMarshaler{},
+	)
+	require.NoError(t, err)
+
+	ctx := context.WithValue(context.Background(), contextKey("key"), "value")
+
+	err = eventBus.Publish(ctx, "message")
+	require.NoError(t, err)
+
+	assert.Equal(t, ctx, publisher.messages["whatever"][0].Context())
+}
+
+func TestEventBus_Send_topic_name(t *testing.T) {
+	cb, err := cqrs.NewEventBus(
+		assertPublishTopicPublisher{ExpectedTopic: "cqrs_test.TestEvent", T: t},
+		func(commandName string) string {
+			return commandName
+		},
+		cqrs.JSONMarshaler{},
+	)
+	require.NoError(t, err)
+
+	err = cb.Publish(context.Background(), TestEvent{})
+	require.NoError(t, err)
+}
+
+func TestEventBus_Send_OnPublish(t *testing.T) {
+	publisher := newPublisherStub()
+
+	eb, err := cqrs.NewEventBusWithConfig(
+		publisher,
+		cqrs.EventBusConfig{
+			GeneratePublishTopic: func(params cqrs.GenerateEventPublishTopicParams) (string, error) {
+				return "whatever", nil
+			},
+			Marshaler: cqrs.JSONMarshaler{},
+			OnPublish: func(params cqrs.OnEventSendParams) error {
+				params.Message.Metadata.Set("key", "value")
+				return nil
+			},
+		},
+	)
+	require.NoError(t, err)
+
+	err = eb.Publish(context.Background(), TestEvent{})
+	require.NoError(t, err)
+
+	assert.Equal(t, "value", publisher.messages["whatever"][0].Metadata.Get("key"))
+}
+
+func TestEventBus_Send_OnPublish_error(t *testing.T) {
+	publisher := newPublisherStub()
+
+	expectedErr := errors.New("some error")
+
+	eb, err := cqrs.NewEventBusWithConfig(
+		publisher,
+		cqrs.EventBusConfig{
+			GeneratePublishTopic: func(params cqrs.GenerateEventPublishTopicParams) (string, error) {
+				return "whatever", nil
+			},
+			Marshaler: cqrs.JSONMarshaler{},
+			OnPublish: func(params cqrs.OnEventSendParams) error {
+				return expectedErr
+			},
+		},
+	)
+	require.NoError(t, err)
+
+	err = eb.Publish(context.Background(), TestEvent{})
+	require.EqualError(t, err, "cannot execute OnPublish: some error")
+}