MM-11272 Added initial post metadata (#9175)

* MM-11272 Added app.PreparePostForClient

* MM-11272 Added app.PreparePostListForClient

* MM-11272 Added EmojiStore.GetMultipleByName

* MM-11272 Added emojis to PreparePostForClient

* MM-11272 Added unit tests for getting reaction counts

* MM-11272 Added unit tests for TestPreparePostForClient

* MM-11272 Added emojis from reactions to Post.Emojis

* MM-11272 Always update post.UpdateAt when reactions change to bust cache

* Fixed merge conflicts

* Moved post metadata-related code into its own file

* Update store mocks

* Fixed typo

* Add missing license headers

* Updated post metadata tests when custom emojis are disabled

* Fix unreliable unit tests

* Fix inconsistent casing in SQL statements

* Fix blank line

* Invalidate store cache after making changes

* Clear post cache synchronously with reactions

api4/channel.go

@@ -488,8 +488,13 @@ func getPinnedPosts(c *Context, w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	w.Header().Set(model.HEADER_ETAG_SERVER, posts.Etag())
-	w.Write([]byte(c.App.PostListWithProxyAddedToImageURLs(posts).ToJson()))
+	clientPostList, err := c.App.PreparePostListForClient(posts)
+	if err != nil {
+		mlog.Error("Failed to prepare posts for getFlaggedPostsForUser response", mlog.Any("err", err))
+	}
+
+	w.Header().Set(model.HEADER_ETAG_SERVER, clientPostList.Etag())
+	w.Write([]byte(clientPostList.ToJson()))
 }
 
 func getPublicChannelsForTeam(c *Context, w http.ResponseWriter, r *http.Request) {

api4/post.go

@@ -9,6 +9,7 @@ import (
 	"strconv"
 	"time"
 
+	"github.com/mattermost/mattermost-server/mlog"
 	"github.com/mattermost/mattermost-server/model"
 )
 
@@ -67,8 +68,13 @@ func createPost(c *Context, w http.ResponseWriter, r *http.Request) {
 	c.App.SetStatusOnline(c.Session.UserId, false)
 	c.App.UpdateLastActivityAtIfNeeded(c.Session)
 
+	clientPost, err := c.App.PreparePostForClient(rp)
+	if err != nil {
+		mlog.Error("Failed to prepare post for createPost response", mlog.Any("err", err))
+	}
+
 	w.WriteHeader(http.StatusCreated)
-	w.Write([]byte(c.App.PostWithProxyAddedToImageURLs(rp).ToJson()))
+	w.Write([]byte(clientPost.ToJson()))
 }
 
 func createEphemeralPost(c *Context, w http.ResponseWriter, r *http.Request) {
@@ -95,8 +101,13 @@ func createEphemeralPost(c *Context, w http.ResponseWriter, r *http.Request) {
 
 	rp := c.App.SendEphemeralPost(ephRequest.UserID, c.App.PostWithProxyRemovedFromImageURLs(ephRequest.Post))
 
+	clientPost, err := c.App.PreparePostForClient(rp)
+	if err != nil {
+		mlog.Error("Failed to prepare post for createEphemeralPost response", mlog.Any("err", err))
+	}
+
 	w.WriteHeader(http.StatusCreated)
-	w.Write([]byte(c.App.PostWithProxyAddedToImageURLs(rp).ToJson()))
+	w.Write([]byte(clientPost.ToJson()))
 }
 
 func getPostsForChannel(c *Context, w http.ResponseWriter, r *http.Request) {
@@ -165,7 +176,13 @@ func getPostsForChannel(c *Context, w http.ResponseWriter, r *http.Request) {
 	if len(etag) > 0 {
 		w.Header().Set(model.HEADER_ETAG_SERVER, etag)
 	}
-	w.Write([]byte(c.App.PostListWithProxyAddedToImageURLs(list).ToJson()))
+
+	clientPostList, err := c.App.PreparePostListForClient(list)
+	if err != nil {
+		mlog.Error("Failed to prepare posts for getPostsForChannel response", mlog.Any("err", err))
+	}
+
+	w.Write([]byte(clientPostList.ToJson()))
 }
 
 func getFlaggedPostsForUser(c *Context, w http.ResponseWriter, r *http.Request) {
@@ -198,7 +215,12 @@ func getFlaggedPostsForUser(c *Context, w http.ResponseWriter, r *http.Request)
 		return
 	}
 
-	w.Write([]byte(c.App.PostListWithProxyAddedToImageURLs(posts).ToJson()))
+	clientPostList, err := c.App.PreparePostListForClient(posts)
+	if err != nil {
+		mlog.Error("Failed to prepare posts for getFlaggedPostsForUser response", mlog.Any("err", err))
+	}
+
+	w.Write([]byte(clientPostList.ToJson()))
 }
 
 func getPost(c *Context, w http.ResponseWriter, r *http.Request) {
@@ -232,12 +254,17 @@ func getPost(c *Context, w http.ResponseWriter, r *http.Request) {
 		}
 	}
 
+	post, err = c.App.PreparePostForClient(post)
+	if err != nil {
+		mlog.Error("Failed to prepare post for getPost response", mlog.Any("err", err))
+	}
+
 	if c.HandleEtag(post.Etag(), "Get Post", w, r) {
 		return
 	}
 
 	w.Header().Set(model.HEADER_ETAG_SERVER, post.Etag())
-	w.Write([]byte(c.App.PostWithProxyAddedToImageURLs(post).ToJson()))
+	w.Write([]byte(post.ToJson()))
 }
 
 func deletePost(c *Context, w http.ResponseWriter, r *http.Request) {
@@ -315,8 +342,14 @@ func getPostThread(c *Context, w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	w.Header().Set(model.HEADER_ETAG_SERVER, list.Etag())
-	w.Write([]byte(c.App.PostListWithProxyAddedToImageURLs(list).ToJson()))
+	clientPostList, err := c.App.PreparePostListForClient(list)
+	if err != nil {
+		mlog.Error("Failed to prepare posts for getFlaggedPostsForUser response", mlog.Any("err", err))
+	}
+
+	w.Header().Set(model.HEADER_ETAG_SERVER, clientPostList.Etag())
+
+	w.Write([]byte(clientPostList.ToJson()))
 }
 
 func searchPosts(c *Context, w http.ResponseWriter, r *http.Request) {
@@ -379,7 +412,12 @@ func searchPosts(c *Context, w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	results = model.MakePostSearchResults(c.App.PostListWithProxyAddedToImageURLs(results.PostList), results.Matches)
+	clientPostList, err := c.App.PreparePostListForClient(results.PostList)
+	if err != nil {
+		mlog.Error("Failed to prepare posts for searchPosts response", mlog.Any("err", err))
+	}
+
+	results = model.MakePostSearchResults(clientPostList, results.Matches)
 
 	w.Header().Set("Cache-Control", "no-cache, no-store, must-revalidate")
 	w.Write([]byte(results.ToJson()))
@@ -430,7 +468,12 @@ func updatePost(c *Context, w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	w.Write([]byte(c.App.PostWithProxyAddedToImageURLs(rpost).ToJson()))
+	rpost, err = c.App.PreparePostForClient(rpost)
+	if err != nil {
+		mlog.Error("Failed to prepare post for updatePost response", mlog.Any("err", err))
+	}
+
+	w.Write([]byte(rpost.ToJson()))
 }
 
 func patchPost(c *Context, w http.ResponseWriter, r *http.Request) {
@@ -470,7 +513,12 @@ func patchPost(c *Context, w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	w.Write([]byte(c.App.PostWithProxyAddedToImageURLs(patchedPost).ToJson()))
+	patchedPost, err = c.App.PreparePostForClient(patchedPost)
+	if err != nil {
+		mlog.Error("Failed to prepare post for patchPost response", mlog.Any("err", err))
+	}
+
+	w.Write([]byte(patchedPost.ToJson()))
 }
 
 func saveIsPinnedPost(c *Context, w http.ResponseWriter, r *http.Request, isPinned bool) {

app/apptestlib.go

@@ -390,6 +390,39 @@ func (me *TestHelper) CreateScheme() (*model.Scheme, []*model.Role) {
 	return scheme, roles
 }
 
+func (me *TestHelper) CreateEmoji() *model.Emoji {
+	utils.DisableDebugLogForTest()
+
+	result := <-me.App.Srv.Store.Emoji().Save(&model.Emoji{
+		CreatorId: me.BasicUser.Id,
+		Name:      model.NewRandomString(10),
+	})
+	if result.Err != nil {
+		panic(result.Err)
+	}
+
+	utils.EnableDebugLogForTest()
+
+	return result.Data.(*model.Emoji)
+}
+
+func (me *TestHelper) AddReactionToPost(post *model.Post, user *model.User, emojiName string) *model.Reaction {
+	utils.DisableDebugLogForTest()
+
+	reaction, err := me.App.SaveReactionForPost(&model.Reaction{
+		UserId:    user.Id,
+		PostId:    post.Id,
+		EmojiName: emojiName,
+	})
+	if err != nil {
+		panic(err)
+	}
+
+	utils.EnableDebugLogForTest()
+
+	return reaction
+}
+
 func (me *TestHelper) TearDown() {
 	me.App.Shutdown()
 	os.Remove(me.tempConfigPath)

app/emoji.go

@@ -185,6 +185,18 @@ func (a *App) GetEmojiByName(emojiName string) (*model.Emoji, *model.AppError) {
 	return result.Data.(*model.Emoji), nil
 }
 
+func (a *App) GetMultipleEmojiByName(names []string) ([]*model.Emoji, *model.AppError) {
+	if !*a.Config().ServiceSettings.EnableCustomEmoji {
+		return nil, model.NewAppError("GetMultipleEmojiByName", "api.emoji.disabled.app_error", nil, "", http.StatusNotImplemented)
+	}
+
+	if result := <-a.Srv.Store.Emoji().GetMultipleByName(names); result.Err != nil {
+		return nil, result.Err
+	} else {
+		return result.Data.([]*model.Emoji), nil
+	}
+}
+
 func (a *App) GetEmojiImage(emojiId string) ([]byte, string, *model.AppError) {
 	result := <-a.Srv.Store.Emoji().Get(emojiId, true)
 	if result.Err != nil {

app/notification.go

@@ -317,8 +317,13 @@ func (a *App) SendNotifications(post *model.Post, team *model.Team, channel *mod
 		}
 	}
 
+	clientPost, err := a.PreparePostForClient(post)
+	if err != nil {
+		mlog.Error("Failed to prepare new post for client", mlog.Any("err", err))
+	}
+
 	message := model.NewWebSocketEvent(model.WEBSOCKET_EVENT_POSTED, "", post.ChannelId, "", nil)
-	message.Add("post", a.PostWithProxyAddedToImageURLs(post).ToJson())
+	message.Add("post", clientPost.ToJson())
 	message.Add("channel_type", channel.Type)
 	message.Add("channel_display_name", notification.GetChannelName(model.SHOW_USERNAME, ""))
 	message.Add("channel_name", channel.Name)

app/post.go

@@ -301,8 +301,13 @@ func (a *App) SendEphemeralPost(userId string, post *model.Post) *model.Post {
 		post.Props = model.StringInterface{}
 	}
 
+	clientPost, err := a.PreparePostForClient(post)
+	if err != nil {
+		mlog.Error("Failed to prepare ephemeral post for client", mlog.Any("err", err))
+	}
+
 	message := model.NewWebSocketEvent(model.WEBSOCKET_EVENT_EPHEMERAL_MESSAGE, "", post.ChannelId, userId, nil)
-	message.Add("post", a.PostWithProxyAddedToImageURLs(post).ToJson())
+	message.Add("post", clientPost.ToJson())
 	a.Publish(message)
 
 	return post
@@ -423,8 +428,13 @@ func (a *App) PatchPost(postId string, patch *model.PostPatch) (*model.Post, *mo
 }
 
 func (a *App) sendUpdatedPostEvent(post *model.Post) {
+	clientPost, err := a.PreparePostForClient(post)
+	if err != nil {
+		mlog.Error("Failed to prepare updated post for client", mlog.Any("err", err))
+	}
+
 	message := model.NewWebSocketEvent(model.WEBSOCKET_EVENT_POST_EDITED, "", post.ChannelId, "", nil)
-	message.Add("post", a.PostWithProxyAddedToImageURLs(post).ToJson())
+	message.Add("post", clientPost.ToJson())
 	a.Publish(message)
 }
 
@@ -563,8 +573,13 @@ func (a *App) DeletePost(postId, deleteByID string) (*model.Post, *model.AppErro
 		return nil, result.Err
 	}
 
+	clientPost, err := a.PreparePostForClient(post)
+	if err != nil {
+		mlog.Error("Failed to prepare deleted post for client", mlog.Any("err", err))
+	}
+
 	message := model.NewWebSocketEvent(model.WEBSOCKET_EVENT_POST_DELETED, "", post.ChannelId, "", nil)
-	message.Add("post", a.PostWithProxyAddedToImageURLs(post).ToJson())
+	message.Add("post", clientPost.ToJson())
 	a.Publish(message)
 
 	a.Go(func() {
@@ -967,13 +982,6 @@ func (a *App) DoPostAction(postId, actionId, userId, selectedOption string) *mod
 	return nil
 }
 
-func (a *App) PostListWithProxyAddedToImageURLs(list *model.PostList) *model.PostList {
-	if f := a.ImageProxyAdder(); f != nil {
-		return list.WithRewrittenImageURLs(f)
-	}
-	return list
-}
-
 func (a *App) PostWithProxyAddedToImageURLs(post *model.Post) *model.Post {
 	if f := a.ImageProxyAdder(); f != nil {
 		return post.WithRewrittenImageURLs(f)

app/post_metadata.go

@@ -0,0 +1,111 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package app
+
+import (
+	"strings"
+
+	"github.com/dyatlov/go-opengraph/opengraph"
+	"github.com/mattermost/mattermost-server/model"
+)
+
+func (a *App) PreparePostListForClient(originalList *model.PostList) (*model.PostList, *model.AppError) {
+	list := &model.PostList{
+		Posts: make(map[string]*model.Post),
+		Order: originalList.Order,
+	}
+
+	for id, originalPost := range originalList.Posts {
+		post, err := a.PreparePostForClient(originalPost)
+		if err != nil {
+			return originalList, err
+		}
+
+		list.Posts[id] = post
+	}
+
+	return list, nil
+}
+
+func (a *App) PreparePostForClient(originalPost *model.Post) (*model.Post, *model.AppError) {
+	post := originalPost.Clone()
+
+	var err *model.AppError
+
+	needReactionCounts := post.ReactionCounts == nil
+	needEmojis := post.Emojis == nil
+	needImageDimensions := post.ImageDimensions == nil
+	needOpenGraphData := post.OpenGraphData == nil
+
+	var reactions []*model.Reaction
+	if needReactionCounts || needEmojis {
+		reactions, err = a.GetReactionsForPost(post.Id)
+		if err != nil {
+			return post, err
+		}
+	}
+
+	if needReactionCounts {
+		post.ReactionCounts = model.CountReactions(reactions)
+	}
+
+	if post.FileInfos == nil {
+		fileInfos, err := a.GetFileInfosForPost(post.Id, false)
+		if err != nil {
+			return post, err
+		}
+
+		post.FileInfos = fileInfos
+	}
+
+	if needEmojis {
+		emojis, err := a.getCustomEmojisForPost(post.Message, reactions)
+		if err != nil {
+			return post, err
+		}
+
+		post.Emojis = emojis
+	}
+
+	post = a.PostWithProxyAddedToImageURLs(post)
+
+	if needImageDimensions || needOpenGraphData {
+		if needImageDimensions {
+			post.ImageDimensions = []*model.PostImageDimensions{}
+		}
+
+		if needOpenGraphData {
+			post.OpenGraphData = []*opengraph.OpenGraph{}
+		}
+
+		// TODO
+	}
+
+	return post, nil
+}
+
+func (a *App) getCustomEmojisForPost(message string, reactions []*model.Reaction) ([]*model.Emoji, *model.AppError) {
+	if !*a.Config().ServiceSettings.EnableCustomEmoji {
+		// Only custom emoji are returned
+		return []*model.Emoji{}, nil
+	}
+
+	names := model.EMOJI_PATTERN.FindAllString(message, -1)
+
+	for _, reaction := range reactions {
+		names = append(names, reaction.EmojiName)
+	}
+
+	if len(names) == 0 {
+		return []*model.Emoji{}, nil
+	}
+
+	names = model.RemoveDuplicateStrings(names)
+
+	for i, name := range names {
+		names[i] = strings.Trim(name, ":")
+	}
+
+	return a.GetMultipleEmojiByName(names)
+}

app/post_metadata_test.go

@@ -0,0 +1,356 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package app
+
+import (
+	"fmt"
+	"testing"
+	"time"
+
+	"github.com/mattermost/mattermost-server/model"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestPreparePostForClient(t *testing.T) {
+	setup := func() *TestHelper {
+		th := Setup().InitBasic()
+
+		th.App.UpdateConfig(func(cfg *model.Config) {
+			*cfg.ServiceSettings.ImageProxyType = ""
+			*cfg.ServiceSettings.ImageProxyURL = ""
+			*cfg.ServiceSettings.ImageProxyOptions = ""
+		})
+
+		return th
+	}
+
+	t.Run("no metadata needed", func(t *testing.T) {
+		th := setup()
+		defer th.TearDown()
+
+		post := th.CreatePost(th.BasicChannel)
+		message := post.Message
+
+		clientPost, err := th.App.PreparePostForClient(post)
+		require.Nil(t, err)
+
+		assert.NotEqual(t, clientPost, post, "should've returned a new post")
+		assert.Equal(t, message, post.Message, "shouldn't have mutated post.Message")
+		assert.NotEqual(t, nil, post.ReactionCounts, "shouldn't have mutated post.ReactionCounts")
+		assert.NotEqual(t, nil, post.FileInfos, "shouldn't have mutated post.FileInfos")
+		assert.NotEqual(t, nil, post.Emojis, "shouldn't have mutated post.Emojis")
+		assert.NotEqual(t, nil, post.ImageDimensions, "shouldn't have mutated post.ImageDimensions")
+		assert.NotEqual(t, nil, post.OpenGraphData, "shouldn't have mutated post.OpenGraphData")
+
+		assert.Equal(t, clientPost.Message, post.Message, "shouldn't have changed Message")
+		assert.Len(t, post.ReactionCounts, 0, "should've populated ReactionCounts")
+		assert.Len(t, post.FileInfos, 0, "should've populated FileInfos")
+		assert.Len(t, post.Emojis, 0, "should've populated Emojis")
+		assert.Len(t, post.ImageDimensions, 0, "should've populated ImageDimensions")
+		assert.Len(t, post.OpenGraphData, 0, "should've populated OpenGraphData")
+	})
+
+	t.Run("metadata already set", func(t *testing.T) {
+		th := setup()
+		defer th.TearDown()
+
+		post, err := th.App.PreparePostForClient(th.CreatePost(th.BasicChannel))
+		require.Nil(t, err)
+
+		clientPost, err := th.App.PreparePostForClient(post)
+		require.Nil(t, err)
+
+		assert.False(t, clientPost == post, "should've returned a new post")
+		assert.Equal(t, clientPost, post, "shouldn't have changed any metadata")
+	})
+
+	t.Run("reaction counts", func(t *testing.T) {
+		th := setup()
+		defer th.TearDown()
+
+		post := th.CreatePost(th.BasicChannel)
+		th.AddReactionToPost(post, th.BasicUser, "smile")
+
+		clientPost, err := th.App.PreparePostForClient(post)
+		require.Nil(t, err)
+
+		assert.Equal(t, model.ReactionCounts{
+			"smile": 1,
+		}, clientPost.ReactionCounts, "should've populated post.ReactionCounts")
+	})
+
+	t.Run("file infos", func(t *testing.T) {
+		th := setup()
+		defer th.TearDown()
+
+		fileInfo, err := th.App.DoUploadFile(time.Now(), th.BasicTeam.Id, th.BasicChannel.Id, th.BasicUser.Id, "test.txt", []byte("test"))
+		require.Nil(t, err)
+
+		post, err := th.App.CreatePost(&model.Post{
+			UserId:    th.BasicUser.Id,
+			ChannelId: th.BasicChannel.Id,
+			FileIds:   []string{fileInfo.Id},
+		}, th.BasicChannel, false)
+		require.Nil(t, err)
+
+		fileInfo.PostId = post.Id
+
+		clientPost, err := th.App.PreparePostForClient(post)
+		require.Nil(t, err)
+
+		assert.Equal(t, []*model.FileInfo{fileInfo}, clientPost.FileInfos, "should've populated post.FileInfos")
+	})
+
+	t.Run("emojis without custom emojis enabled", func(t *testing.T) {
+		th := setup()
+		defer th.TearDown()
+
+		th.App.UpdateConfig(func(cfg *model.Config) {
+			*cfg.ServiceSettings.EnableCustomEmoji = false
+		})
+
+		emoji := th.CreateEmoji()
+
+		post, err := th.App.CreatePost(&model.Post{
+			UserId:    th.BasicUser.Id,
+			ChannelId: th.BasicChannel.Id,
+			Message:   ":" + emoji.Name + ": :taco:",
+		}, th.BasicChannel, false)
+		require.Nil(t, err)
+
+		th.AddReactionToPost(post, th.BasicUser, "smile")
+		th.AddReactionToPost(post, th.BasicUser, "angry")
+		th.AddReactionToPost(post, th.BasicUser2, "angry")
+
+		clientPost, err := th.App.PreparePostForClient(post)
+		require.Nil(t, err)
+
+		assert.Len(t, clientPost.ReactionCounts, 2, "should've populated post.ReactionCounts")
+		assert.Equal(t, 1, clientPost.ReactionCounts["smile"], "should've populated post.ReactionCounts for smile")
+		assert.Equal(t, 2, clientPost.ReactionCounts["angry"], "should've populated post.ReactionCounts for angry")
+		assert.ElementsMatch(t, []*model.Emoji{}, clientPost.Emojis, "should've populated empty post.Emojis")
+	})
+
+	t.Run("emojis with custom emojis enabled", func(t *testing.T) {
+		th := setup()
+		defer th.TearDown()
+
+		th.App.UpdateConfig(func(cfg *model.Config) {
+			*cfg.ServiceSettings.EnableCustomEmoji = true
+		})
+
+		emoji1 := th.CreateEmoji()
+		emoji2 := th.CreateEmoji()
+		emoji3 := th.CreateEmoji()
+
+		post, err := th.App.CreatePost(&model.Post{
+			UserId:    th.BasicUser.Id,
+			ChannelId: th.BasicChannel.Id,
+			Message:   ":" + emoji3.Name + ": :taco:",
+		}, th.BasicChannel, false)
+		require.Nil(t, err)
+
+		th.AddReactionToPost(post, th.BasicUser, emoji1.Name)
+		th.AddReactionToPost(post, th.BasicUser, emoji2.Name)
+		th.AddReactionToPost(post, th.BasicUser2, emoji2.Name)
+		th.AddReactionToPost(post, th.BasicUser2, "angry")
+
+		clientPost, err := th.App.PreparePostForClient(post)
+		require.Nil(t, err)
+
+		assert.Len(t, clientPost.ReactionCounts, 3, "should've populated post.ReactionCounts")
+		assert.Equal(t, 1, clientPost.ReactionCounts[emoji1.Name], "should've populated post.ReactionCounts for emoji1")
+		assert.Equal(t, 2, clientPost.ReactionCounts[emoji2.Name], "should've populated post.ReactionCounts for emoji2")
+		assert.Equal(t, 1, clientPost.ReactionCounts["angry"], "should've populated post.ReactionCounts for angry")
+		assert.ElementsMatch(t, []*model.Emoji{emoji1, emoji2, emoji3}, clientPost.Emojis, "should've populated post.Emojis")
+	})
+
+	t.Run("linked image dimensions", func(t *testing.T) {
+		// TODO
+	})
+
+	t.Run("proxy linked images", func(t *testing.T) {
+		th := setup()
+		defer th.TearDown()
+
+		testProxyLinkedImage(t, th, false)
+	})
+
+	t.Run("opengraph", func(t *testing.T) {
+		// TODO
+	})
+
+	t.Run("opengraph image dimensions", func(t *testing.T) {
+		// TODO
+	})
+
+	t.Run("proxy opengraph images", func(t *testing.T) {
+		// TODO
+	})
+}
+
+func TestPreparePostForClientWithImageProxy(t *testing.T) {
+	setup := func() *TestHelper {
+		th := Setup().InitBasic()
+
+		th.App.UpdateConfig(func(cfg *model.Config) {
+			*cfg.ServiceSettings.SiteURL = "http://mymattermost.com"
+			*cfg.ServiceSettings.ImageProxyType = "atmos/camo"
+			*cfg.ServiceSettings.ImageProxyURL = "https://127.0.0.1"
+			*cfg.ServiceSettings.ImageProxyOptions = "foo"
+		})
+
+		return th
+	}
+
+	t.Run("proxy linked images", func(t *testing.T) {
+		th := setup()
+		defer th.TearDown()
+
+		testProxyLinkedImage(t, th, true)
+	})
+
+	t.Run("proxy opengraph images", func(t *testing.T) {
+		// TODO
+	})
+}
+
+func testProxyLinkedImage(t *testing.T, th *TestHelper, shouldProxy bool) {
+	postTemplate := "![foo](%v)"
+	imageURL := "http://mydomain.com/myimage"
+	proxiedImageURL := "https://127.0.0.1/f8dace906d23689e8d5b12c3cefbedbf7b9b72f5/687474703a2f2f6d79646f6d61696e2e636f6d2f6d79696d616765"
+
+	post := &model.Post{
+		UserId:    th.BasicUser.Id,
+		ChannelId: th.BasicChannel.Id,
+		Message:   fmt.Sprintf(postTemplate, imageURL),
+	}
+
+	var err *model.AppError
+	post, err = th.App.CreatePost(post, th.BasicChannel, false)
+	require.Nil(t, err)
+
+	clientPost, err := th.App.PreparePostForClient(post)
+	require.Nil(t, err)
+
+	if shouldProxy {
+		assert.Equal(t, post.Message, fmt.Sprintf(postTemplate, imageURL), "should not have mutated original post")
+		assert.Equal(t, clientPost.Message, fmt.Sprintf(postTemplate, proxiedImageURL), "should've replaced linked image URLs")
+	} else {
+		assert.Equal(t, clientPost.Message, fmt.Sprintf(postTemplate, imageURL), "shouldn't have replaced linked image URLs")
+	}
+}
+
+func TestGetCustomEmojisForPost_Message(t *testing.T) {
+	th := Setup().InitBasic()
+	defer th.TearDown()
+
+	th.App.UpdateConfig(func(cfg *model.Config) {
+		*cfg.ServiceSettings.EnableCustomEmoji = true
+	})
+
+	emoji1 := th.CreateEmoji()
+	emoji2 := th.CreateEmoji()
+	emoji3 := th.CreateEmoji()
+
+	testCases := []struct {
+		Description      string
+		Input            string
+		Expected         []*model.Emoji
+		SkipExpectations bool
+	}{
+		{
+			Description:      "no emojis",
+			Input:            "this is a string",
+			Expected:         []*model.Emoji{},
+			SkipExpectations: true,
+		},
+		{
+			Description: "one emoji",
+			Input:       "this is an :" + emoji1.Name + ": string",
+			Expected: []*model.Emoji{
+				emoji1,
+			},
+		},
+		{
+			Description: "two emojis",
+			Input:       "this is a :" + emoji3.Name + ": :" + emoji2.Name + ": string",
+			Expected: []*model.Emoji{
+				emoji3,
+				emoji2,
+			},
+		},
+		{
+			Description: "punctuation around emojis",
+			Input:       ":" + emoji3.Name + ":/:" + emoji1.Name + ": (:" + emoji2.Name + ":)",
+			Expected: []*model.Emoji{
+				emoji3,
+				emoji1,
+				emoji2,
+			},
+		},
+		{
+			Description: "adjacent emojis",
+			Input:       ":" + emoji3.Name + "::" + emoji1.Name + ":",
+			Expected: []*model.Emoji{
+				emoji3,
+				emoji1,
+			},
+		},
+		{
+			Description: "duplicate emojis",
+			Input:       "" + emoji1.Name + ": :" + emoji1.Name + ": :" + emoji1.Name + ": :" + emoji2.Name + ": :" + emoji2.Name + ": :" + emoji1.Name + ":",
+			Expected: []*model.Emoji{
+				emoji1,
+				emoji2,
+			},
+		},
+		{
+			Description: "fake emojis",
+			Input:       "these don't exist :tomato: :potato: :rotato:",
+			Expected:    []*model.Emoji{},
+		},
+		{
+			Description: "fake and real emojis",
+			Input:       ":tomato::" + emoji1.Name + ": :potato: :" + emoji2.Name + ":",
+			Expected: []*model.Emoji{
+				emoji1,
+				emoji2,
+			},
+		},
+	}
+
+	for _, testCase := range testCases {
+		testCase := testCase
+		t.Run(testCase.Description, func(t *testing.T) {
+			emojis, err := th.App.getCustomEmojisForPost(testCase.Input, nil)
+			assert.Nil(t, err, "failed to get emojis in message")
+			assert.ElementsMatch(t, emojis, testCase.Expected, "received incorrect emojis")
+		})
+	}
+}
+
+func TestGetCustomEmojisForPost(t *testing.T) {
+	th := Setup().InitBasic()
+	defer th.TearDown()
+
+	th.App.UpdateConfig(func(cfg *model.Config) {
+		*cfg.ServiceSettings.EnableCustomEmoji = true
+	})
+
+	emoji1 := th.CreateEmoji()
+	emoji2 := th.CreateEmoji()
+
+	reactions := []*model.Reaction{
+		{
+			UserId:    th.BasicUser.Id,
+			EmojiName: emoji1.Name,
+		},
+	}
+
+	emojis, err := th.App.getCustomEmojisForPost(":"+emoji2.Name+":", reactions)
+	assert.Nil(t, err, "failed to get emojis for post")
+	assert.ElementsMatch(t, emojis, []*model.Emoji{emoji1, emoji2}, "received incorrect emojis")
+}

app/post_test.go

@@ -466,7 +466,6 @@ func TestImageProxy(t *testing.T) {
 			list := model.NewPostList()
 			list.Posts[post.Id] = post
 
-			assert.Equal(t, "![foo]("+tc.ProxiedImageURL+")", th.App.PostListWithProxyAddedToImageURLs(list).Posts[post.Id].Message)
 			assert.Equal(t, "![foo]("+tc.ProxiedImageURL+")", th.App.PostWithProxyAddedToImageURLs(post).Message)
 
 			assert.Equal(t, "![foo]("+tc.ImageURL+")", th.App.PostWithProxyRemovedFromImageURLs(post).Message)

app/reaction.go

@@ -6,6 +6,7 @@ package app
 import (
 	"net/http"
 
+	"github.com/mattermost/mattermost-server/mlog"
 	"github.com/mattermost/mattermost-server/model"
 )
 
@@ -42,6 +43,9 @@ func (a *App) SaveReactionForPost(reaction *model.Reaction) (*model.Reaction, *m
 
 	reaction = result.Data.(*model.Reaction)
 
+	// The post is always modified since the UpdateAt always changes
+	a.InvalidateCacheForChannelPosts(post.ChannelId)
+
 	a.Go(func() {
 		a.sendReactionEvent(model.WEBSOCKET_EVENT_REACTION_ADDED, reaction, post, true)
 	})
@@ -92,6 +96,9 @@ func (a *App) DeleteReactionForPost(reaction *model.Reaction) *model.AppError {
 		return result.Err
 	}
 
+	// The post is always modified since the UpdateAt always changes
+	a.InvalidateCacheForChannelPosts(post.ChannelId)
+
 	a.Go(func() {
 		a.sendReactionEvent(model.WEBSOCKET_EVENT_REACTION_REMOVED, reaction, post, hasReactions)
 	})
@@ -105,11 +112,15 @@ func (a *App) sendReactionEvent(event string, reaction *model.Reaction, post *mo
 	message.Add("reaction", reaction.ToJson())
 	a.Publish(message)
 
-	// The post is always modified since the UpdateAt always changes
-	a.InvalidateCacheForChannelPosts(post.ChannelId)
-	post.HasReactions = hasReactions
-	post.UpdateAt = model.GetMillis()
+	clientPost, err := a.PreparePostForClient(post)
+	if err != nil {
+		mlog.Error("Failed to prepare new post for client after reaction", mlog.Any("err", err))
+	}
+
+	clientPost.HasReactions = hasReactions
+	clientPost.UpdateAt = model.GetMillis()
+
 	umessage := model.NewWebSocketEvent(model.WEBSOCKET_EVENT_POST_EDITED, "", post.ChannelId, "", nil)
-	umessage.Add("post", a.PostWithProxyAddedToImageURLs(post).ToJson())
+	umessage.Add("post", clientPost.ToJson())
 	a.Publish(umessage)
 }

model/emoji.go

@@ -7,6 +7,7 @@ import (
 	"encoding/json"
 	"io"
 	"net/http"
+	"regexp"
 )
 
 const (
@@ -14,6 +15,8 @@ const (
 	EMOJI_SORT_BY_NAME    = "name"
 )
 
+var EMOJI_PATTERN = regexp.MustCompile(`:[a-zA-Z0-9_-]+:`)
+
 type Emoji struct {
 	Id        string `json:"id"`
 	CreateAt  int64  `json:"create_at"`

model/post.go

@@ -11,6 +11,7 @@ import (
 	"strings"
 	"unicode/utf8"
 
+	"github.com/dyatlov/go-opengraph/opengraph"
 	"github.com/mattermost/mattermost-server/utils/markdown"
 )
 
@@ -78,9 +79,22 @@ type Post struct {
 	Props         StringInterface `json:"props"`
 	Hashtags      string          `json:"hashtags"`
 	Filenames     StringArray     `json:"filenames,omitempty"` // Deprecated, do not use this field any more
-	FileIds       StringArray     `json:"file_ids,omitempty"`
+	FileIds       StringArray     `json:"file_ids,omitempty"`  // Deprecated, do not use this field any more
 	PendingPostId string          `json:"pending_post_id" db:"-"`
-	HasReactions  bool            `json:"has_reactions,omitempty"`
+	HasReactions  bool            `json:"has_reactions,omitempty"` // Deprecated, do not use this field any more
+
+	// Transient fields populated before sending posts to the client
+	ReactionCounts  ReactionCounts         `json:"reaction_counts" db:"-"`
+	FileInfos       []*FileInfo            `json:"file_infos" db:"-"`
+	ImageDimensions []*PostImageDimensions `json:"image_dimensions" db:"-"`
+	OpenGraphData   []*opengraph.OpenGraph `json:"opengraph_data" db:"-"`
+	Emojis          []*Emoji               `json:"emojis" db:"-"`
+}
+
+type PostImageDimensions struct {
+	URL    string `json:"url"`
+	Width  int64  `json:"width"`
+	Height int64  `json:"height"`
 }
 
 type PostEphemeral struct {
@@ -170,10 +184,16 @@ type PostActionIntegrationResponse struct {
 	EphemeralText string `json:"ephemeral_text"`
 }
 
-func (o *Post) ToJson() string {
+// Shallowly clone the a post
+func (o *Post) Clone() *Post {
 	copy := *o
+	return &copy
+}
+
+func (o *Post) ToJson() string {
+	copy := o.Clone()
 	copy.StripActionIntegrations()
-	b, _ := json.Marshal(&copy)
+	b, _ := json.Marshal(copy)
 	return string(b)
 }
 
@@ -502,12 +522,12 @@ var markdownDestinationEscaper = strings.NewReplacer(
 // WithRewrittenImageURLs returns a new shallow copy of the post where the message has been
 // rewritten via RewriteImageURLs.
 func (o *Post) WithRewrittenImageURLs(f func(string) string) *Post {
-	copy := *o
+	copy := o.Clone()
 	copy.Message = RewriteImageURLs(o.Message, f)
 	if copy.MessageSource == "" && copy.Message != o.Message {
 		copy.MessageSource = o.Message
 	}
-	return &copy
+	return copy
 }
 
 func (o *PostEphemeral) ToUnsanitizedJson() string {

model/reaction.go

@@ -17,6 +17,8 @@ type Reaction struct {
 	CreateAt  int64  `json:"create_at"`
 }
 
+type ReactionCounts map[string]int
+
 func (o *Reaction) ToJson() string {
 	b, _ := json.Marshal(o)
 	return string(b)
@@ -74,3 +76,13 @@ func (o *Reaction) PreSave() {
 		o.CreateAt = GetMillis()
 	}
 }
+
+func CountReactions(reactions []*Reaction) ReactionCounts {
+	reactionCounts := ReactionCounts{}
+
+	for _, reaction := range reactions {
+		reactionCounts[reaction.EmojiName] += 1
+	}
+
+	return reactionCounts
+}

model/reaction_test.go

@@ -82,3 +82,38 @@ func TestReactionIsValid(t *testing.T) {
 		t.Fatal("create at should be invalid")
 	}
 }
+
+func TestCountReactions(t *testing.T) {
+	userId := NewId()
+	userId2 := NewId()
+
+	reactions := []*Reaction{
+		{
+			UserId:    userId,
+			EmojiName: "smile",
+		},
+		{
+			UserId:    userId,
+			EmojiName: "frowning",
+		},
+		{
+			UserId:    userId2,
+			EmojiName: "smile",
+		},
+		{
+			UserId:    userId2,
+			EmojiName: "neutral_face",
+		},
+	}
+
+	reactionCounts := CountReactions(reactions)
+	if len(reactionCounts) != 3 {
+		t.Fatal("should've received counts for 3 reactions")
+	} else if reactionCounts["smile"] != 2 {
+		t.Fatal("should've received 2 smile reactions")
+	} else if reactionCounts["frowning"] != 1 {
+		t.Fatal("should've received 1 frowning reaction")
+	} else if reactionCounts["neutral_face"] != 1 {
+		t.Fatal("should've received 2 neutral_face reaction")
+	}
+}

store/local_cache_supplier_roles.go

@@ -18,10 +18,11 @@ func (s *LocalCacheSupplier) handleClusterInvalidateRole(msg *model.ClusterMessa
 }
 
 func (s *LocalCacheSupplier) RoleSave(ctx context.Context, role *model.Role, hints ...LayeredStoreHint) *LayeredStoreSupplierResult {
+	result := s.Next().RoleSave(ctx, role, hints...)
 	if len(role.Id) != 0 {
-		defer s.doInvalidateCacheCluster(s.roleCache, role.Name)
+		s.doInvalidateCacheCluster(s.roleCache, role.Name)
 	}
-	return s.Next().RoleSave(ctx, role, hints...)
+	return result
 }
 
 func (s *LocalCacheSupplier) RoleGet(ctx context.Context, roleId string, hints ...LayeredStoreHint) *LayeredStoreSupplierResult {
@@ -81,8 +82,10 @@ func (s *LocalCacheSupplier) RoleDelete(ctx context.Context, roleId string, hint
 }
 
 func (s *LocalCacheSupplier) RolePermanentDeleteAll(ctx context.Context, hints ...LayeredStoreHint) *LayeredStoreSupplierResult {
-	defer s.roleCache.Purge()
-	defer s.doClearCacheCluster(s.roleCache)
+	result := s.Next().RolePermanentDeleteAll(ctx, hints...)
 
-	return s.Next().RolePermanentDeleteAll(ctx, hints...)
+	s.roleCache.Purge()
+	s.doClearCacheCluster(s.roleCache)
+
+	return result
 }

store/local_cache_supplier_schemes.go

@@ -18,10 +18,11 @@ func (s *LocalCacheSupplier) handleClusterInvalidateScheme(msg *model.ClusterMes
 }
 
 func (s *LocalCacheSupplier) SchemeSave(ctx context.Context, scheme *model.Scheme, hints ...LayeredStoreHint) *LayeredStoreSupplierResult {
+	result := s.Next().SchemeSave(ctx, scheme, hints...)
 	if len(scheme.Id) != 0 {
-		defer s.doInvalidateCacheCluster(s.schemeCache, scheme.Id)
+		s.doInvalidateCacheCluster(s.schemeCache, scheme.Id)
 	}
-	return s.Next().SchemeSave(ctx, scheme, hints...)
+	return result
 }
 
 func (s *LocalCacheSupplier) SchemeGet(ctx context.Context, schemeId string, hints ...LayeredStoreHint) *LayeredStoreSupplierResult {
@@ -41,10 +42,12 @@ func (s *LocalCacheSupplier) SchemeGetByName(ctx context.Context, schemeName str
 }
 
 func (s *LocalCacheSupplier) SchemeDelete(ctx context.Context, schemeId string, hints ...LayeredStoreHint) *LayeredStoreSupplierResult {
-	defer s.doInvalidateCacheCluster(s.schemeCache, schemeId)
-	defer s.doClearCacheCluster(s.roleCache)
+	result := s.Next().SchemeDelete(ctx, schemeId, hints...)
 
-	return s.Next().SchemeDelete(ctx, schemeId, hints...)
+	s.doInvalidateCacheCluster(s.schemeCache, schemeId)
+	s.doClearCacheCluster(s.roleCache)
+
+	return result
 }
 
 func (s *LocalCacheSupplier) SchemeGetAllPage(ctx context.Context, scope string, offset int, limit int, hints ...LayeredStoreHint) *LayeredStoreSupplierResult {

store/redis_supplier_roles.go

@@ -13,6 +13,7 @@ import (
 
 func (s *RedisSupplier) RoleSave(ctx context.Context, role *model.Role, hints ...LayeredStoreHint) *LayeredStoreSupplierResult {
 	key := buildRedisKeyForRoleName(role.Name)
+	result := s.Next().RoleSave(ctx, role, hints...)
 
 	defer func() {
 		if err := s.client.Del(key).Err(); err != nil {
@@ -20,7 +21,7 @@ func (s *RedisSupplier) RoleSave(ctx context.Context, role *model.Role, hints ..
 		}
 	}()
 
-	return s.Next().RoleSave(ctx, role, hints...)
+	return result
 }
 
 func (s *RedisSupplier) RoleGet(ctx context.Context, roleId string, hints ...LayeredStoreHint) *LayeredStoreSupplierResult {
@@ -86,6 +87,7 @@ func (s *RedisSupplier) RoleGetByNames(ctx context.Context, roleNames []string,
 }
 
 func (s *RedisSupplier) RoleDelete(ctx context.Context, roleId string, hints ...LayeredStoreHint) *LayeredStoreSupplierResult {
+	// XXXXXX Shouldn't this call Role
 	result := s.Next().RoleGet(ctx, roleId, hints...)
 
 	if result.Err == nil {
@@ -103,17 +105,17 @@ func (s *RedisSupplier) RoleDelete(ctx context.Context, roleId string, hints ...
 }
 
 func (s *RedisSupplier) RolePermanentDeleteAll(ctx context.Context, hints ...LayeredStoreHint) *LayeredStoreSupplierResult {
-	defer func() {
-		if keys, err := s.client.Keys("roles:*").Result(); err != nil {
-			mlog.Error("Redis encountered an error on read: " + err.Error())
-		} else {
-			if err := s.client.Del(keys...).Err(); err != nil {
-				mlog.Error("Redis encountered an error on delete: " + err.Error())
-			}
-		}
-	}()
+	result := s.Next().RolePermanentDeleteAll(ctx, hints...)
 
-	return s.Next().RolePermanentDeleteAll(ctx, hints...)
+	if keys, err := s.client.Keys("roles:*").Result(); err != nil {
+		mlog.Error("Redis encountered an error on read: " + err.Error())
+	} else {
+		if err := s.client.Del(keys...).Err(); err != nil {
+			mlog.Error("Redis encountered an error on delete: " + err.Error())
+		}
+	}
+
+	return result
 }
 
 func buildRedisKeyForRoleName(roleName string) string {

store/redis_supplier_schemes.go

@@ -10,31 +10,37 @@ import (
 )
 
 func (s *RedisSupplier) SchemeSave(ctx context.Context, scheme *model.Scheme, hints ...LayeredStoreHint) *LayeredStoreSupplierResult {
+	result := s.Next().SchemeSave(ctx, scheme, hints...)
 	// TODO: Redis caching.
-	return s.Next().SchemeSave(ctx, scheme, hints...)
+	return result
 }
 
 func (s *RedisSupplier) SchemeGet(ctx context.Context, schemeId string, hints ...LayeredStoreHint) *LayeredStoreSupplierResult {
+	result := s.Next().SchemeGet(ctx, schemeId, hints...)
 	// TODO: Redis caching.
-	return s.Next().SchemeGet(ctx, schemeId, hints...)
+	return result
 }
 
 func (s *RedisSupplier) SchemeGetByName(ctx context.Context, schemeName string, hints ...LayeredStoreHint) *LayeredStoreSupplierResult {
+	result := s.Next().SchemeGetByName(ctx, schemeName, hints...)
 	// TODO: Redis caching.
-	return s.Next().SchemeGetByName(ctx, schemeName, hints...)
+	return result
 }
 
 func (s *RedisSupplier) SchemeDelete(ctx context.Context, schemeId string, hints ...LayeredStoreHint) *LayeredStoreSupplierResult {
+	result := s.Next().SchemeDelete(ctx, schemeId, hints...)
 	// TODO: Redis caching.
-	return s.Next().SchemeDelete(ctx, schemeId, hints...)
+	return result
 }
 
 func (s *RedisSupplier) SchemeGetAllPage(ctx context.Context, scope string, offset int, limit int, hints ...LayeredStoreHint) *LayeredStoreSupplierResult {
+	result := s.Next().SchemeGetAllPage(ctx, scope, offset, limit, hints...)
 	// TODO: Redis caching.
-	return s.Next().SchemeGetAllPage(ctx, scope, offset, limit, hints...)
+	return result
 }
 
 func (s *RedisSupplier) SchemePermanentDeleteAll(ctx context.Context, hints ...LayeredStoreHint) *LayeredStoreSupplierResult {
+	result := s.Next().SchemePermanentDeleteAll(ctx, hints...)
 	// TODO: Redis caching.
-	return s.Next().SchemePermanentDeleteAll(ctx, hints...)
+	return result
 }

store/sqlstore/emoji_store.go

@@ -5,6 +5,7 @@ package sqlstore
 
 import (
 	"database/sql"
+	"fmt"
 	"net/http"
 
 	"github.com/mattermost/mattermost-server/einterfaces"
@@ -128,6 +129,27 @@ func (es SqlEmojiStore) GetByName(name string) store.StoreChannel {
 	})
 }
 
+func (es SqlEmojiStore) GetMultipleByName(names []string) store.StoreChannel {
+	return store.Do(func(result *store.StoreResult) {
+		keys, params := MapStringsToQueryParams(names, "Emoji")
+
+		var emojis []*model.Emoji
+
+		if _, err := es.GetReplica().Select(&emojis,
+			`SELECT
+				*
+			FROM
+				Emoji
+			WHERE
+				Name IN `+keys+`
+				AND DeleteAt = 0`, params); err != nil {
+			result.Err = model.NewAppError("SqlEmojiStore.GetByName", "store.sql_emoji.get_by_name.app_error", nil, fmt.Sprintf("names=%v, %v", names, err.Error()), http.StatusInternalServerError)
+		} else {
+			result.Data = emojis
+		}
+	})
+}
+
 func (es SqlEmojiStore) GetList(offset, limit int, sort string) store.StoreChannel {
 	return store.Do(func(result *store.StoreResult) {
 		var emoji []*model.Emoji
@@ -151,7 +173,7 @@ func (es SqlEmojiStore) GetList(offset, limit int, sort string) store.StoreChann
 func (es SqlEmojiStore) Delete(id string, time int64) store.StoreChannel {
 	return store.Do(func(result *store.StoreResult) {
 		if sqlResult, err := es.GetMaster().Exec(
-			`Update
+			`UPDATE
 				Emoji
 			SET
 				DeleteAt = :DeleteAt,

store/sqlstore/post_store.go

@@ -4,7 +4,6 @@
 package sqlstore
 
 import (
-	"bytes"
 	"fmt"
 	"net/http"
 	"regexp"
@@ -1144,19 +1143,9 @@ func (s *SqlPostStore) GetPostsCreatedAt(channelId string, time int64) store.Sto
 
 func (s *SqlPostStore) GetPostsByIds(postIds []string) store.StoreChannel {
 	return store.Do(func(result *store.StoreResult) {
-		keys := bytes.Buffer{}
-		params := make(map[string]interface{})
-		for i, postId := range postIds {
-			if keys.Len() > 0 {
-				keys.WriteString(",")
-			}
+		keys, params := MapStringsToQueryParams(postIds, "Post")
 
-			key := "Post" + strconv.Itoa(i)
-			keys.WriteString(":" + key)
-			params[key] = postId
-		}
-
-		query := `SELECT * FROM Posts WHERE Id in (` + keys.String() + `) ORDER BY CreateAt DESC`
+		query := `SELECT * FROM Posts WHERE Id IN ` + keys + ` ORDER BY CreateAt DESC`
 
 		var posts []*model.Post
 		_, err := s.GetReplica().Select(&posts, query, params)

store/sqlstore/supplier_reactions.go

@@ -192,22 +192,18 @@ func deleteReactionAndUpdatePost(transaction *gorp.Transaction, reaction *model.
 }
 
 const (
-	// Set HasReactions = true if and only if the post has reactions, update UpdateAt only if HasReactions changes
 	UPDATE_POST_HAS_REACTIONS_ON_DELETE_QUERY = `UPDATE
 			Posts
 		SET
-			UpdateAt = (CASE
-				WHEN HasReactions != (SELECT count(0) > 0 FROM Reactions WHERE PostId = :PostId) THEN :UpdateAt
-				ELSE UpdateAt
-			END),
+			UpdateAt = :UpdateAt,
 			HasReactions = (SELECT count(0) > 0 FROM Reactions WHERE PostId = :PostId)
 		WHERE
 			Id = :PostId`
 )
 
 func updatePostForReactionsOnDelete(transaction *gorp.Transaction, postId string) error {
-	_, err := transaction.Exec(UPDATE_POST_HAS_REACTIONS_ON_DELETE_QUERY, map[string]interface{}{"PostId": postId, "UpdateAt": model.GetMillis()})
-
+	updateAt := model.GetMillis()
+	_, err := transaction.Exec(UPDATE_POST_HAS_REACTIONS_ON_DELETE_QUERY, map[string]interface{}{"PostId": postId, "UpdateAt": updateAt})
 	return err
 }
 
@@ -219,7 +215,7 @@ func updatePostForReactionsOnInsert(transaction *gorp.Transaction, postId string
 			HasReactions = True,
 			UpdateAt = :UpdateAt
 		WHERE
-			Id = :PostId AND HasReactions = False`,
+			Id = :PostId`,
 		map[string]interface{}{"PostId": postId, "UpdateAt": model.GetMillis()})
 
 	return err

store/sqlstore/utils.go

@@ -0,0 +1,28 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package sqlstore
+
+import (
+	"bytes"
+	"fmt"
+	"strconv"
+)
+
+// Converts a list of strings into a list of query parameters and a named parameter map that can
+// be used as part of a SQL query.
+func MapStringsToQueryParams(list []string, paramPrefix string) (string, map[string]interface{}) {
+	keys := bytes.Buffer{}
+	params := make(map[string]interface{})
+	for i, entry := range list {
+		if keys.Len() > 0 {
+			keys.WriteString(",")
+		}
+
+		key := paramPrefix + strconv.Itoa(i)
+		keys.WriteString(":" + key)
+		params[key] = entry
+	}
+
+	return fmt.Sprintf("(%v)", keys.String()), params
+}

store/sqlstore/utils_test.go

@@ -0,0 +1,32 @@
+package sqlstore
+
+import (
+	"testing"
+)
+
+func TestMapStringsToQueryParams(t *testing.T) {
+	t.Run("one item", func(t *testing.T) {
+		input := []string{"apple"}
+
+		keys, params := MapStringsToQueryParams(input, "Fruit")
+
+		if len(params) != 1 || params["Fruit0"] != "apple" {
+			t.Fatal("returned incorrect params", params)
+		} else if keys != "(:Fruit0)" {
+			t.Fatal("returned incorrect query", keys)
+		}
+	})
+
+	t.Run("multiple items", func(t *testing.T) {
+		input := []string{"carrot", "tomato", "potato"}
+
+		keys, params := MapStringsToQueryParams(input, "Vegetable")
+
+		if len(params) != 3 || params["Vegetable0"] != "carrot" ||
+			params["Vegetable1"] != "tomato" || params["Vegetable2"] != "potato" {
+			t.Fatal("returned incorrect params", params)
+		} else if keys != "(:Vegetable0,:Vegetable1,:Vegetable2)" {
+			t.Fatal("returned incorrect query", keys)
+		}
+	})
+}

store/store.go

@@ -427,6 +427,7 @@ type EmojiStore interface {
 	Save(emoji *model.Emoji) StoreChannel
 	Get(id string, allowFromCache bool) StoreChannel
 	GetByName(name string) StoreChannel
+	GetMultipleByName(names []string) StoreChannel
 	GetList(offset, limit int, sort string) StoreChannel
 	Delete(id string, time int64) StoreChannel
 	Search(name string, prefixOnly bool, limit int) StoreChannel

store/storetest/emoji_store.go

@@ -17,6 +17,7 @@ func TestEmojiStore(t *testing.T, ss store.Store) {
 	t.Run("EmojiSaveDelete", func(t *testing.T) { testEmojiSaveDelete(t, ss) })
 	t.Run("EmojiGet", func(t *testing.T) { testEmojiGet(t, ss) })
 	t.Run("EmojiGetByName", func(t *testing.T) { testEmojiGetByName(t, ss) })
+	t.Run("EmojiGetMultipleByName", func(t *testing.T) { testEmojiGetMultipleByName(t, ss) })
 	t.Run("EmojiGetList", func(t *testing.T) { testEmojiGetList(t, ss) })
 	t.Run("EmojiSearch", func(t *testing.T) { testEmojiSearch(t, ss) })
 }
@@ -132,6 +133,64 @@ func testEmojiGetByName(t *testing.T, ss store.Store) {
 	}
 }
 
+func testEmojiGetMultipleByName(t *testing.T, ss store.Store) {
+	emojis := []model.Emoji{
+		{
+			CreatorId: model.NewId(),
+			Name:      model.NewId(),
+		},
+		{
+			CreatorId: model.NewId(),
+			Name:      model.NewId(),
+		},
+		{
+			CreatorId: model.NewId(),
+			Name:      model.NewId(),
+		},
+	}
+
+	for i, emoji := range emojis {
+		emojis[i] = *store.Must(ss.Emoji().Save(&emoji)).(*model.Emoji)
+	}
+	defer func() {
+		for _, emoji := range emojis {
+			store.Must(ss.Emoji().Delete(emoji.Id, time.Now().Unix()))
+		}
+	}()
+
+	t.Run("one emoji", func(t *testing.T) {
+		if result := <-ss.Emoji().GetMultipleByName([]string{emojis[0].Name}); result.Err != nil {
+			t.Fatal("could not get emoji", result.Err)
+		} else if received := result.Data.([]*model.Emoji); len(received) != 1 || *received[0] != emojis[0] {
+			t.Fatal("got incorrect emoji")
+		}
+	})
+
+	t.Run("multiple emojis", func(t *testing.T) {
+		if result := <-ss.Emoji().GetMultipleByName([]string{emojis[0].Name, emojis[1].Name, emojis[2].Name}); result.Err != nil {
+			t.Fatal("could not get emojis", result.Err)
+		} else if received := result.Data.([]*model.Emoji); len(received) != 3 {
+			t.Fatal("got incorrect emojis")
+		}
+	})
+
+	t.Run("one nonexistent emoji", func(t *testing.T) {
+		if result := <-ss.Emoji().GetMultipleByName([]string{"ab"}); result.Err != nil {
+			t.Fatal("could not get emoji", result.Err)
+		} else if received := result.Data.([]*model.Emoji); len(received) != 0 {
+			t.Fatal("got incorrect emoji")
+		}
+	})
+
+	t.Run("multiple emojis with nonexistent names", func(t *testing.T) {
+		if result := <-ss.Emoji().GetMultipleByName([]string{emojis[0].Name, emojis[1].Name, emojis[2].Name, "abcd", "1234"}); result.Err != nil {
+			t.Fatal("could not get emojis", result.Err)
+		} else if received := result.Data.([]*model.Emoji); len(received) != 3 {
+			t.Fatal("got incorrect emojis")
+		}
+	})
+}
+
 func testEmojiGetList(t *testing.T, ss store.Store) {
 	emojis := []model.Emoji{
 		{

store/storetest/mocks/EmojiStore.go

@@ -77,6 +77,22 @@ func (_m *EmojiStore) GetList(offset int, limit int, sort string) store.StoreCha
 	return r0
 }
 
+// GetMultipleByName provides a mock function with given fields: names
+func (_m *EmojiStore) GetMultipleByName(names []string) store.StoreChannel {
+	ret := _m.Called(names)
+
+	var r0 store.StoreChannel
+	if rf, ok := ret.Get(0).(func([]string) store.StoreChannel); ok {
+		r0 = rf(names)
+	} else {
+		if ret.Get(0) != nil {
+			r0 = ret.Get(0).(store.StoreChannel)
+		}
+	}
+
+	return r0
+}
+
 // Save provides a mock function with given fields: emoji
 func (_m *EmojiStore) Save(emoji *model.Emoji) store.StoreChannel {
 	ret := _m.Called(emoji)

store/storetest/reaction_store.go

@@ -61,8 +61,8 @@ func testReactionSave(t *testing.T, ss store.Store) {
 		t.Fatal(result.Err)
 	}
 
-	if postList := store.Must(ss.Post().Get(reaction2.PostId)).(*model.PostList); postList.Posts[post.Id].UpdateAt != secondUpdateAt {
-		t.Fatal("shouldn't mark as updated when HasReactions hasn't changed")
+	if postList := store.Must(ss.Post().Get(reaction2.PostId)).(*model.PostList); postList.Posts[post.Id].UpdateAt == secondUpdateAt {
+		t.Fatal("should've marked post as updated even if HasReactions doesn't change")
 	}
 
 	// different post
@@ -123,7 +123,7 @@ func testReactionDelete(t *testing.T, ss store.Store) {
 	if postList := store.Must(ss.Post().Get(post.Id)).(*model.PostList); postList.Posts[post.Id].HasReactions {
 		t.Fatal("should've set HasReactions = false on post")
 	} else if postList.Posts[post.Id].UpdateAt == firstUpdateAt {
-		t.Fatal("shouldn't mark as updated when HasReactions has changed after deleting reactions")
+		t.Fatal("should mark post as updated after deleting reactions")
 	}
 }