PLT-1378 Initial version of emoji reactions (#4520)

* Refactored emoji.json to support multiple aliases and emoji categories

* Added custom category to emoji.jsx and stabilized all fields

* Removed conflicting aliases for :mattermost: and :ca:

* fixup after store changes

* Added emoji reactions

* Removed reactions for an emoji when that emoji is deleted

* Fixed incorrect test case

* Renamed ReactionList to ReactionListView

* Fixed 👍 and 👎 not showing up as possible reactions

* Removed text emoticons from emoji reaction autocomplete

* Changed emoji reactions to be sorted by the order that they were first created

* Set a maximum number of listeners for the ReactionStore

* Removed unused code from Textbox component

* Fixed reaction permissions

* Changed error code when trying to modify reactions for another user

* Fixed merge conflicts

* Properly applied theme colours to reactions

* Fixed ESLint and gofmt errors

* Fixed ReactionListContainer to properly update when its post prop changes

* Removed unnecessary escape characters from reaction regexes

* Shared reaction message pattern between CreatePost and CreateComment

* Removed an unnecessary select query when saving a reaction

* Changed reactions route to be under /reactions

* Fixed copyright dates on newly added files

* Removed debug code that prevented all unit tests from being ran

* Cleaned up unnecessary code for reactions

* Renamed ReactionStore.List to ReactionStore.GetForPost

model/reaction.go

@@ -0,0 +1,78 @@
+// Copyright (c) 2016 Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package model
+
+import (
+	"encoding/json"
+	"io"
+)
+
+type Reaction struct {
+	UserId    string `json:"user_id"`
+	PostId    string `json:"post_id"`
+	EmojiName string `json:"emoji_name"`
+	CreateAt  int64  `json:"create_at"`
+}
+
+func (o *Reaction) ToJson() string {
+	if b, err := json.Marshal(o); err != nil {
+		return ""
+	} else {
+		return string(b)
+	}
+}
+
+func ReactionFromJson(data io.Reader) *Reaction {
+	var o Reaction
+
+	if err := json.NewDecoder(data).Decode(&o); err != nil {
+		return nil
+	} else {
+		return &o
+	}
+}
+
+func ReactionsToJson(o []*Reaction) string {
+	if b, err := json.Marshal(o); err != nil {
+		return ""
+	} else {
+		return string(b)
+	}
+}
+
+func ReactionsFromJson(data io.Reader) []*Reaction {
+	var o []*Reaction
+
+	if err := json.NewDecoder(data).Decode(&o); err != nil {
+		return nil
+	} else {
+		return o
+	}
+}
+
+func (o *Reaction) IsValid() *AppError {
+	if len(o.UserId) != 26 {
+		return NewLocAppError("Reaction.IsValid", "model.reaction.is_valid.user_id.app_error", nil, "user_id="+o.UserId)
+	}
+
+	if len(o.PostId) != 26 {
+		return NewLocAppError("Reaction.IsValid", "model.reaction.is_valid.post_id.app_error", nil, "post_id="+o.PostId)
+	}
+
+	if len(o.EmojiName) == 0 || len(o.EmojiName) > 64 {
+		return NewLocAppError("Reaction.IsValid", "model.reaction.is_valid.emoji_name.app_error", nil, "emoji_name="+o.EmojiName)
+	}
+
+	if o.CreateAt == 0 {
+		return NewLocAppError("Reaction.IsValid", "model.reaction.is_valid.create_at.app_error", nil, "")
+	}
+
+	return nil
+}
+
+func (o *Reaction) PreSave() {
+	if o.CreateAt == 0 {
+		o.CreateAt = GetMillis()
+	}
+}