PLT-7379: Timestamp on deleted, ephemeral, or pending post is a permalink (#7295)

* Removed permalink from system messages, general cleanup

* Removed permalink from deleted messages

* Removed permalink from pending messages

* Fixed post_info tests

* Changed permalink logic to remove permalinks from ephemeral messages, but leave them in place for system messages.

* Fixed check style

webapp/utils/post_utils.jsx

@@ -9,7 +9,7 @@ import UserStore from 'stores/user_store.jsx';
 import ChannelStore from 'stores/channel_store.jsx';
 
 export function isSystemMessage(post) {
-    return post.type && (post.type.lastIndexOf(Constants.SYSTEM_MESSAGE_PREFIX) === 0);
+    return Boolean(post.type && (post.type.lastIndexOf(Constants.SYSTEM_MESSAGE_PREFIX) === 0));
 }
 
 export function isFromWebhook(post) {
@@ -53,11 +53,11 @@ export function getProfilePicSrcForPost(post, user) {
 }
 
 export function canDeletePost(post) {
-    var isOwner = isPostOwner(post);
-    var isSystemAdmin = UserStore.isSystemAdminForCurrentUser();
-    var isTeamAdmin = TeamStore.isTeamAdminForCurrentTeam() || isSystemAdmin;
-    var isChannelAdmin = ChannelStore.isChannelAdminForCurrentChannel() || isTeamAdmin;
-    var isAdmin = isChannelAdmin || isTeamAdmin || isSystemAdmin;
+    const isOwner = isPostOwner(post);
+    const isSystemAdmin = UserStore.isSystemAdminForCurrentUser();
+    const isTeamAdmin = TeamStore.isTeamAdminForCurrentTeam() || isSystemAdmin;
+    const isChannelAdmin = ChannelStore.isChannelAdminForCurrentChannel() || isTeamAdmin;
+    const isAdmin = isChannelAdmin || isTeamAdmin || isSystemAdmin;
 
     if (global.window.mm_license.IsLicensed === 'true') {
         return (global.window.mm_config.RestrictPostDelete === Constants.PERMISSIONS_DELETE_POST_ALL && (isOwner || isChannelAdmin)) ||
@@ -69,15 +69,14 @@ export function canDeletePost(post) {
 }
 
 export function canEditPost(post, editDisableAction) {
-    var isOwner = isPostOwner(post);
-
-    var canEdit = isOwner && !isSystemMessage(post);
+    const isOwner = isPostOwner(post);
+    let canEdit = isOwner && !isSystemMessage(post);
 
     if (canEdit && global.window.mm_license.IsLicensed === 'true') {
         if (global.window.mm_config.AllowEditPost === Constants.ALLOW_EDIT_POST_NEVER) {
             canEdit = false;
         } else if (global.window.mm_config.AllowEditPost === Constants.ALLOW_EDIT_POST_TIME_LIMIT) {
-            var timeLeft = (post.create_at + (global.window.mm_config.PostEditTimeLimit * 1000)) - Utils.getTimestamp();
+            const timeLeft = (post.create_at + (global.window.mm_config.PostEditTimeLimit * 1000)) - Utils.getTimestamp();
             if (timeLeft > 0) {
                 editDisableAction.fireAfter(timeLeft + 1000);
             } else {