[Dembo] Add slack notification client

plugins/slack-notification-plugin/slack/client.go

@@ -0,0 +1,34 @@
+package slack
+
+import (
+	"github.com/go-resty/resty/v2"
+)
+
+type SlackClient interface {
+	Publish(message Message) error
+}
+
+type slackClient struct {
+	client *resty.Client
+	config SlackConfig
+}
+
+func (s *slackClient) Publish(message Message) error {
+	messageJson, err := message.JSON()
+	if err != nil {
+		return err
+	}
+	path := s.config.url
+	_, err = s.client.R().
+		SetBody(messageJson).
+		SetHeader("Content-Type", "application/json").
+		Post(path)
+	return err
+}
+
+func NewSlackClient(client *resty.Client) SlackClient {
+	return &slackClient{
+		client: client,
+		config: NewSlackConfig(),
+	}
+}

plugins/slack-notification-plugin/slack/client_test.go

@@ -0,0 +1,102 @@
+package slack
+
+import (
+	"errors"
+	"io/ioutil"
+	"net/http"
+	"testing"
+
+	"github.com/go-resty/resty/v2"
+	"github.com/jarcoal/httpmock"
+	"github.com/stretchr/testify/assert"
+)
+
+type slackClientTest struct {
+	client SlackClient
+}
+
+func (context *slackClientTest) setUp(t *testing.T) {
+	httpClient := resty.New()
+	httpmock.ActivateNonDefault(httpClient.GetClient())
+	context.client = NewSlackClient(httpClient)
+	assert.NotNil(t, context.client)
+}
+
+func (context *slackClientTest) tearDown() {
+	httpmock.DeactivateAndReset()
+}
+
+func newNotificationServiceTestContext() *slackClientTest {
+	return &slackClientTest{}
+}
+
+func TestSlackClient_Publish(t *testing.T) {
+	ctx := newNotificationServiceTestContext()
+	ctx.setUp(t)
+	defer ctx.tearDown()
+
+	config := NewSlackConfig()
+	message := MessageMock{}
+	message.On("JSON").Return("message sent", nil)
+
+	httpmock.RegisterResponder(
+		"POST",
+		config.url,
+		func(req *http.Request) (*http.Response, error) {
+			body, err := ioutil.ReadAll(req.Body)
+			assert.NoError(t, err)
+			assert.Equal(t, "message sent", string(body))
+
+			contentType := req.Header.Get("Content-type")
+			assert.Equal(t, "application/json", contentType)
+
+			response := httpmock.NewStringResponse(200, "")
+			return response, nil
+		},
+	)
+	err := ctx.client.Publish(&message)
+	assert.NoError(t, err)
+	assert.Equal(t, 1, httpmock.GetTotalCallCount())
+}
+
+func TestSlackClient_PublishErrorJSON(t *testing.T) {
+	ctx := newNotificationServiceTestContext()
+	ctx.setUp(t)
+	defer ctx.tearDown()
+
+	message := MessageMock{}
+	message.On("JSON").Return("", errors.New("JSON unmarshal error")).Once()
+
+	err := ctx.client.Publish(&message)
+	assert.Error(t, err)
+	assert.Equal(t, 0, httpmock.GetTotalCallCount())
+}
+
+func TestSlackClient_PublishErrorRequest(t *testing.T) {
+	ctx := newNotificationServiceTestContext()
+	ctx.setUp(t)
+	defer ctx.tearDown()
+
+	config := NewSlackConfig()
+	message := MessageMock{}
+	message.On("JSON").Return("message sent", nil)
+
+	httpmock.RegisterResponder(
+		"POST",
+		config.url,
+		func(req *http.Request) (*http.Response, error) {
+			body, err := ioutil.ReadAll(req.Body)
+			assert.NoError(t, err)
+			assert.Equal(t, "message sent", string(body))
+
+			contentType := req.Header.Get("Content-type")
+			assert.Equal(t, "application/json", contentType)
+
+			response := httpmock.NewStringResponse(503, "")
+			return response, errors.New("internal server error")
+		},
+	)
+	err := ctx.client.Publish(&message)
+	assert.Error(t, err)
+	assert.Equal(t, 1, httpmock.GetTotalCallCount())
+}

plugins/slack-notification-plugin/slack/config.go

@@ -0,0 +1,18 @@
+package slack
+
+import "github.com/spf13/viper"
+
+type SlackConfig struct {
+	url string
+}
+
+func NewSlackConfig() SlackConfig {
+	fang := viper.New()
+	fang.AutomaticEnv()
+	fang.SetEnvPrefix("SLACK_PLUGIN")
+	fang.SetDefault("URL", "https://hooks.slack.com/services")
+	config := SlackConfig{
+		url: fang.GetString("URL"),
+	}
+	return config
+}

plugins/slack-notification-plugin/slack/message.go

@@ -0,0 +1,5 @@
+package slack
+
+type Message interface {
+	JSON() (string, error)
+}

plugins/slack-notification-plugin/slack/message_mock.go

@@ -0,0 +1,14 @@
+package slack
+
+import (
+	"github.com/stretchr/testify/mock"
+)
+
+type MessageMock struct {
+	mock.Mock
+}
+
+func (m *MessageMock) JSON() (string, error) {
+	args := m.Called()
+	return args.Get(0).(string), args.Error(1)
+}