Add SendMail to plugin API (#10082)

* Add SendMail to plugin API

* Update per feedback

Co-Authored-By: cpanato <ctadeu@gmail.com>

app/plugin_api.go

@@ -540,6 +540,24 @@ func (api *PluginAPI) RemoveTeamIcon(teamId string) *model.AppError {
 	return nil
 }
 
+// Mail Section
+
+func (api *PluginAPI) SendMail(to, subject, htmlBody string) *model.AppError {
+	if to == "" {
+		return model.NewAppError("SendMail", "plugin_api.send_mail.missing_to", nil, "", http.StatusBadRequest)
+	}
+
+	if subject == "" {
+		return model.NewAppError("SendMail", "plugin_api.send_mail.missing_subject", nil, "", http.StatusBadRequest)
+	}
+
+	if htmlBody == "" {
+		return model.NewAppError("SendMail", "plugin_api.send_mail.missing_htmlbody", nil, "", http.StatusBadRequest)
+	}
+
+	return api.app.SendMail(to, subject, htmlBody)
+}
+
 // Plugin Section
 
 func (api *PluginAPI) GetPlugins() ([]*model.Manifest, *model.AppError) {

app/plugin_api_test.go

@@ -19,6 +19,7 @@ import (
 
 	"github.com/mattermost/mattermost-server/model"
 	"github.com/mattermost/mattermost-server/plugin"
+	"github.com/mattermost/mattermost-server/services/mailservice"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
@@ -690,3 +691,33 @@ func TestPluginAPIGetDirectChannel(t *testing.T) {
 	require.NotNil(t, err)
 	require.Empty(t, dm3)
 }
+
+func TestPluginAPISendMail(t *testing.T) {
+	th := Setup().InitBasic()
+	defer th.TearDown()
+	api := th.SetupPluginAPI()
+
+	to := th.BasicUser.Email
+	subject := "testing plugin api sending email"
+	body := "this is a test."
+
+	err := api.SendMail(to, subject, body)
+	require.Nil(t, err)
+
+	// Check if we received the email
+	var resultsMailbox mailservice.JSONMessageHeaderInbucket
+	errMail := mailservice.RetryInbucket(5, func() error {
+		var err error
+		resultsMailbox, err = mailservice.GetMailBox(to)
+		return err
+	})
+	require.Nil(t, errMail)
+	require.NotZero(t, len(resultsMailbox))
+	require.True(t, strings.ContainsAny(resultsMailbox[len(resultsMailbox)-1].To[0], to))
+
+	resultsEmail, err1 := mailservice.GetMessageFromMailbox(to, resultsMailbox[len(resultsMailbox)-1].ID)
+	require.Nil(t, err1)
+	require.Equal(t, resultsEmail.Subject, subject)
+	require.Equal(t, resultsEmail.Body.Text, body)
+
+}

i18n/en.json

@@ -4934,6 +4934,18 @@
     "id": "plugin.api.update_user_status.bad_status",
     "translation": "Unable to set the user status. Unknown user status."
   },
+  {
+    "id": "plugin_api.send_mail.missing_htmlbody",
+    "translation": "Missing HTML Body."
+  },
+  {
+    "id": "plugin_api.send_mail.missing_to",
+    "translation": "Missing TO address."
+  },
+  {
+    "id": "plugin_api.send_mail.missing_subject",
+    "translation": "Missing email subject."
+  },
   {
     "id": "store.sql_channel.remove_all_deactivated_members.app_error",
     "translation": "We could not remove the deactivated users from the channel"

plugin/api.go

@@ -465,6 +465,11 @@ type API interface {
 	// do not need to add that info.
 	// keyValuePairs should be primitive go types or other values that can be encoded by encoding/gob
 	LogWarn(msg string, keyValuePairs ...interface{})
+
+	// SendMail sends an email to a specific address
+	//
+	// Minimum server version: 5.7
+	SendMail(to, subject, htmlBody string) *model.AppError
 }
 
 var handshake = plugin.HandshakeConfig{

plugin/client_rpc_generated.go

@@ -3556,3 +3556,33 @@ func (s *apiRPCServer) LogWarn(args *Z_LogWarnArgs, returns *Z_LogWarnReturns) e
 	}
 	return nil
 }
+
+type Z_SendMailArgs struct {
+	A string
+	B string
+	C string
+}
+
+type Z_SendMailReturns struct {
+	A *model.AppError
+}
+
+func (g *apiRPCClient) SendMail(to, subject, htmlBody string) *model.AppError {
+	_args := &Z_SendMailArgs{to, subject, htmlBody}
+	_returns := &Z_SendMailReturns{}
+	if err := g.client.Call("Plugin.SendMail", _args, _returns); err != nil {
+		log.Printf("RPC call to SendMail API failed: %s", err.Error())
+	}
+	return _returns.A
+}
+
+func (s *apiRPCServer) SendMail(args *Z_SendMailArgs, returns *Z_SendMailReturns) error {
+	if hook, ok := s.impl.(interface {
+		SendMail(to, subject, htmlBody string) *model.AppError
+	}); ok {
+		returns.A = hook.SendMail(args.A, args.B, args.C)
+	} else {
+		return encodableError(fmt.Errorf("API SendMail called but not implemented."))
+	}
+	return nil
+}

plugin/plugintest/api.go

@@ -1974,6 +1974,22 @@ func (_m *API) SendEphemeralPost(userId string, post *model.Post) *model.Post {
 	return r0
 }
 
+// SendMail provides a mock function with given fields: to, subject, htmlBody
+func (_m *API) SendMail(to string, subject string, htmlBody string) *model.AppError {
+	ret := _m.Called(to, subject, htmlBody)
+
+	var r0 *model.AppError
+	if rf, ok := ret.Get(0).(func(string, string, string) *model.AppError); ok {
+		r0 = rf(to, subject, htmlBody)
+	} else {
+		if ret.Get(0) != nil {
+			r0 = ret.Get(0).(*model.AppError)
+		}
+	}
+
+	return r0
+}
+
 // SetProfileImage provides a mock function with given fields: userId, data
 func (_m *API) SetProfileImage(userId string, data []byte) *model.AppError {
 	ret := _m.Called(userId, data)