3 files changed, 74 insertions, 4 deletions

diff --git a/app/channel.go b/app/channel.go
index 6e11d4e5d..40f21c3a9 100644
--- a/app/channel.go
+++ b/app/channel.go
@@ -652,8 +652,10 @@ func (a *App) AddChannelMember(userId string, channel *model.Channel, userReques
 	}
 
 	var userRequestor *model.User
-	if userRequestor, err = a.GetUser(userRequestorId); err != nil {
-		return nil, err
+	if userRequestorId != "" {
+		if userRequestor, err = a.GetUser(userRequestorId); err != nil {
+			return nil, err
+		}
 	}
 
 	cm, err := a.AddUserToChannel(user, channel)
@@ -661,7 +663,7 @@ func (a *App) AddChannelMember(userId string, channel *model.Channel, userReques
 		return nil, err
 	}
 
-	if userId == userRequestorId {
+	if userRequestorId == "" || userId == userRequestorId {
 		a.postJoinChannelMessage(user, channel)
 	} else {
 		a.Go(func() {
@@ -669,7 +671,9 @@ func (a *App) AddChannelMember(userId string, channel *model.Channel, userReques
 		})
 	}
 
-	a.UpdateChannelLastViewedAt([]string{channel.Id}, userRequestor.Id)
+	if userRequestor != nil {
+		a.UpdateChannelLastViewedAt([]string{channel.Id}, userRequestor.Id)
+	}
 
 	return cm, nil
 }
diff --git a/app/channel_test.go b/app/channel_test.go
index 69efaeca7..a4e0806a6 100644
--- a/app/channel_test.go
+++ b/app/channel_test.go
@@ -340,3 +340,44 @@ func TestRemoveUserFromChannelUpdatesChannelMemberHistoryRecord(t *testing.T) {
 	assert.Equal(t, publicChannel.Id, histories[0].ChannelId)
 	assert.NotNil(t, histories[0].LeaveTime)
 }
+
+func TestAddChannelMemberNoUserRequestor(t *testing.T) {
+	th := Setup().InitBasic()
+	defer th.TearDown()
+
+	// create a user and add it to a channel
+	user := th.CreateUser()
+	if _, err := th.App.AddTeamMember(th.BasicTeam.Id, user.Id); err != nil {
+		t.Fatal("Failed to add user to team. Error: " + err.Message)
+	}
+
+	groupUserIds := make([]string, 0)
+	groupUserIds = append(groupUserIds, th.BasicUser.Id)
+	groupUserIds = append(groupUserIds, user.Id)
+
+	channel := th.createChannel(th.BasicTeam, model.CHANNEL_OPEN)
+	userRequestorId := ""
+	postRootId := ""
+	if _, err := th.App.AddChannelMember(user.Id, channel, userRequestorId, postRootId); err != nil {
+		t.Fatal("Failed to add user to channel. Error: " + err.Message)
+	}
+
+	// there should be a ChannelMemberHistory record for the user
+	histories := store.Must(th.App.Srv.Store.ChannelMemberHistory().GetUsersInChannelDuring(model.GetMillis()-100, model.GetMillis()+100, channel.Id)).([]*model.ChannelMemberHistoryResult)
+	assert.Len(t, histories, 2)
+	channelMemberHistoryUserIds := make([]string, 0)
+	for _, history := range histories {
+		assert.Equal(t, channel.Id, history.ChannelId)
+		channelMemberHistoryUserIds = append(channelMemberHistoryUserIds, history.UserId)
+	}
+	assert.Equal(t, groupUserIds, channelMemberHistoryUserIds)
+
+	postList := store.Must(th.App.Srv.Store.Post().GetPosts(channel.Id, 0, 1, false)).(*model.PostList)
+	if assert.Len(t, postList.Order, 1) {
+		post := postList.Posts[postList.Order[0]]
+
+		assert.Equal(t, model.POST_JOIN_CHANNEL, post.Type)
+		assert.Equal(t, user.Id, post.UserId)
+		assert.Equal(t, user.Username, post.Props["username"])
+	}
+}
diff --git a/app/plugin_api.go b/app/plugin_api.go
index 21b828368..b09a0c419 100644
--- a/app/plugin_api.go
+++ b/app/plugin_api.go
@@ -124,10 +124,35 @@ func (api *PluginAPI) UpdateChannel(channel *model.Channel) (*model.Channel, *mo
 	return api.app.UpdateChannel(channel)
 }
 
+func (api *PluginAPI) AddChannelMember(channelId, userId string) (*model.ChannelMember, *model.AppError) {
+	// For now, don't allow overriding these via the plugin API.
+	userRequestorId := ""
+	postRootId := ""
+
+	channel, err := api.GetChannel(channelId)
+	if err != nil {
+		return nil, err
+	}
+
+	return api.app.AddChannelMember(userId, channel, userRequestorId, postRootId)
+}
+
 func (api *PluginAPI) GetChannelMember(channelId, userId string) (*model.ChannelMember, *model.AppError) {
 	return api.app.GetChannelMember(channelId, userId)
 }
 
+func (api *PluginAPI) UpdateChannelMemberRoles(channelId, userId, newRoles string) (*model.ChannelMember, *model.AppError) {
+	return api.app.UpdateChannelMemberRoles(channelId, userId, newRoles)
+}
+
+func (api *PluginAPI) UpdateChannelMemberNotifications(channelId, userId string, notifications map[string]string) (*model.ChannelMember, *model.AppError) {
+	return api.app.UpdateChannelMemberNotifyProps(notifications, channelId, userId)
+}
+
+func (api *PluginAPI) DeleteChannelMember(channelId, userId string) *model.AppError {
+	return api.app.LeaveChannel(channelId, userId)
+}
+
 func (api *PluginAPI) CreatePost(post *model.Post) (*model.Post, *model.AppError) {
 	return api.app.CreatePostMissingChannel(post, true)
 }