test(service): add mocks and tests for slack

service/slack/mock_slack_client.go

@@ -0,0 +1,65 @@
+// Code generated by mockery v2.14.0. DO NOT EDIT.
+
+package slack
+
+import (
+	context "context"
+
+	slack_goslack "github.com/slack-go/slack"
+	mock "github.com/stretchr/testify/mock"
+)
+
+// mockSlackClient is an autogenerated mock type for the slackClient type
+type mockSlackClient struct {
+	mock.Mock
+}
+
+// PostMessageContext provides a mock function with given fields: ctx, channelID, options
+func (_m *mockSlackClient) PostMessageContext(ctx context.Context, channelID string, options ...slack_goslack.MsgOption) (string, string, error) {
+	_va := make([]interface{}, len(options))
+	for _i := range options {
+		_va[_i] = options[_i]
+	}
+	var _ca []interface{}
+	_ca = append(_ca, ctx, channelID)
+	_ca = append(_ca, _va...)
+	ret := _m.Called(_ca...)
+
+	var r0 string
+	if rf, ok := ret.Get(0).(func(context.Context, string, ...slack_goslack.MsgOption) string); ok {
+		r0 = rf(ctx, channelID, options...)
+	} else {
+		r0 = ret.Get(0).(string)
+	}
+
+	var r1 string
+	if rf, ok := ret.Get(1).(func(context.Context, string, ...slack_goslack.MsgOption) string); ok {
+		r1 = rf(ctx, channelID, options...)
+	} else {
+		r1 = ret.Get(1).(string)
+	}
+
+	var r2 error
+	if rf, ok := ret.Get(2).(func(context.Context, string, ...slack_goslack.MsgOption) error); ok {
+		r2 = rf(ctx, channelID, options...)
+	} else {
+		r2 = ret.Error(2)
+	}
+
+	return r0, r1, r2
+}
+
+type mockConstructorTestingTnewMockSlackClient interface {
+	mock.TestingT
+	Cleanup(func())
+}
+
+// newMockSlackClient creates a new instance of mockSlackClient. It also registers a testing interface on the mock and a cleanup function to assert the mocks expectations.
+func newMockSlackClient(t mockConstructorTestingTnewMockSlackClient) *mockSlackClient {
+	mock := &mockSlackClient{}
+	mock.Mock.Test(t)
+
+	t.Cleanup(func() { mock.AssertExpectations(t) })
+
+	return mock
+}

service/slack/slack.go

@@ -7,9 +7,17 @@ import (
 	"github.com/slack-go/slack"
 )
 
+//go:generate mockery --name=slackClient --output=. --case=underscore --inpackage
+type slackClient interface {
+	PostMessageContext(ctx context.Context, channelID string, options ...slack.MsgOption) (string, string, error)
+}
+
+// Compile-time check to ensure that slack.Client implements the slackClient interface.
+var _ slackClient = new(slack.Client)
+
 // Slack struct holds necessary data to communicate with the Slack API.
 type Slack struct {
-	client     *slack.Client
+	client     slackClient
 	channelIDs []string
 }
 

service/slack/slack_test.go

@@ -0,0 +1,84 @@
+package slack
+
+import (
+	"context"
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+	"github.com/pkg/errors"
+	"github.com/stretchr/testify/mock"
+	"github.com/stretchr/testify/require"
+)
+
+func TestNew(t *testing.T) {
+	t.Parallel()
+
+	assert := require.New(t)
+
+	service := New("")
+	assert.NotNil(service)
+}
+
+func TestSlack_AddReceivers(t *testing.T) {
+	t.Parallel()
+
+	assert := require.New(t)
+
+	service := New("")
+	assert.NotNil(service)
+
+	service.AddReceivers("")
+	assert.Len(service.channelIDs, 1)
+
+	service.AddReceivers("", "")
+	assert.Len(service.channelIDs, 3)
+
+	service.channelIDs = []string{}
+	receivers := []string{"", ""}
+	service.AddReceivers(receivers...)
+
+	diff := cmp.Diff(service.channelIDs, receivers)
+	assert.Equal("", diff)
+}
+
+func TestSlack_Send(t *testing.T) {
+	t.Parallel()
+
+	assert := require.New(t)
+
+	service := New("")
+	assert.NotNil(service)
+
+	// No receivers added
+	ctx := context.Background()
+	err := service.Send(ctx, "subject", "message")
+	assert.Nil(err)
+
+	// Test error response
+	mockClient := newMockSlackClient(t)
+	mockClient.
+		On("PostMessageContext", ctx, "1234", mock.AnythingOfType("MsgOption")).
+		Return("", "", errors.New("some error"))
+
+	service.client = mockClient
+	service.AddReceivers("1234")
+	err = service.Send(ctx, "subject", "message")
+	assert.NotNil(err)
+	mockClient.AssertExpectations(t)
+
+	// Test success response
+	mockClient = newMockSlackClient(t)
+	mockClient.
+		On("PostMessageContext", ctx, "1234", mock.AnythingOfType("MsgOption")).
+		Return("", "", nil)
+
+	mockClient.
+		On("PostMessageContext", ctx, "5678", mock.AnythingOfType("MsgOption")).
+		Return("", "", nil)
+
+	service.client = mockClient
+	service.AddReceivers("5678")
+	err = service.Send(ctx, "subject", "message")
+	assert.Nil(err)
+	mockClient.AssertExpectations(t)
+}