Add optimized function to determine whether event has text to display

Signed-off-by: Robin Townsend <robin@robin.town>

src/TextForEvent.js

@@ -21,6 +21,10 @@ import SettingsStore from "./settings/SettingsStore";
 import {ALL_RULE_TYPES, ROOM_RULE_TYPES, SERVER_RULE_TYPES, USER_RULE_TYPES} from "./mjolnir/BanList";
 import {WIDGET_LAYOUT_EVENT_TYPE} from "./stores/widgets/WidgetLayoutStore";
 
+// These functions are frequently used just to check whether an event has
+// any text to display at all. For this reason they return deferred values
+// to avoid the expense of looking up translations when they're not needed.
+
 function textForMemberEvent(ev) {
     // XXX: SYJS-16 "sender is sometimes null for join messages"
     const senderName = ev.sender ? ev.sender.name : ev.getSender();
@@ -28,84 +32,84 @@ function textForMemberEvent(ev) {
     const prevContent = ev.getPrevContent();
     const content = ev.getContent();
 
-    const reason = content.reason ? (_t('Reason') + ': ' + content.reason) : '';
+    const getReason = () => content.reason ? (_t('Reason') + ': ' + content.reason) : '';
     switch (content.membership) {
         case 'invite': {
             const threePidContent = content.third_party_invite;
             if (threePidContent) {
                 if (threePidContent.display_name) {
-                    return _t('%(targetName)s accepted the invitation for %(displayName)s.', {
+                    return () => _t('%(targetName)s accepted the invitation for %(displayName)s.', {
                         targetName,
                         displayName: threePidContent.display_name,
                     });
                 } else {
-                    return _t('%(targetName)s accepted an invitation.', {targetName});
+                    return () => _t('%(targetName)s accepted an invitation.', {targetName});
                 }
             } else {
-                return _t('%(senderName)s invited %(targetName)s.', {senderName, targetName});
+                return () => _t('%(senderName)s invited %(targetName)s.', {senderName, targetName});
             }
         }
         case 'ban':
-            return _t('%(senderName)s banned %(targetName)s.', {senderName, targetName}) + ' ' + reason;
+            return () => _t('%(senderName)s banned %(targetName)s.', {senderName, targetName}) + ' ' + getReason();
         case 'join':
             if (prevContent && prevContent.membership === 'join') {
                 if (prevContent.displayname && content.displayname && prevContent.displayname !== content.displayname) {
-                    return _t('%(oldDisplayName)s changed their display name to %(displayName)s.', {
+                    return () => _t('%(oldDisplayName)s changed their display name to %(displayName)s.', {
                         oldDisplayName: prevContent.displayname,
                         displayName: content.displayname,
                     });
                 } else if (!prevContent.displayname && content.displayname) {
-                    return _t('%(senderName)s set their display name to %(displayName)s.', {
+                    return () => _t('%(senderName)s set their display name to %(displayName)s.', {
                         senderName: ev.getSender(),
                         displayName: content.displayname,
                     });
                 } else if (prevContent.displayname && !content.displayname) {
-                    return _t('%(senderName)s removed their display name (%(oldDisplayName)s).', {
+                    return () => _t('%(senderName)s removed their display name (%(oldDisplayName)s).', {
                         senderName,
                         oldDisplayName: prevContent.displayname,
                     });
                 } else if (prevContent.avatar_url && !content.avatar_url) {
-                    return _t('%(senderName)s removed their profile picture.', {senderName});
+                    return () => _t('%(senderName)s removed their profile picture.', {senderName});
                 } else if (prevContent.avatar_url && content.avatar_url &&
                     prevContent.avatar_url !== content.avatar_url) {
-                    return _t('%(senderName)s changed their profile picture.', {senderName});
+                    return () => _t('%(senderName)s changed their profile picture.', {senderName});
                 } else if (!prevContent.avatar_url && content.avatar_url) {
-                    return _t('%(senderName)s set a profile picture.', {senderName});
+                    return () => _t('%(senderName)s set a profile picture.', {senderName});
                 } else if (SettingsStore.getValue("showHiddenEventsInTimeline")) {
                     // This is a null rejoin, it will only be visible if the Labs option is enabled
-                    return _t("%(senderName)s made no change.", {senderName});
+                    return () => _t("%(senderName)s made no change.", {senderName});
                 } else {
-                    return "";
+                    return null;
                 }
             } else {
                 if (!ev.target) console.warn("Join message has no target! -- " + ev.getContent().state_key);
-                return _t('%(targetName)s joined the room.', {targetName});
+                return () => _t('%(targetName)s joined the room.', {targetName});
             }
         case 'leave':
             if (ev.getSender() === ev.getStateKey()) {
                 if (prevContent.membership === "invite") {
-                    return _t('%(targetName)s rejected the invitation.', {targetName});
+                    return () => _t('%(targetName)s rejected the invitation.', {targetName});
                 } else {
-                    return _t('%(targetName)s left the room.', {targetName});
+                    return () => _t('%(targetName)s left the room.', {targetName});
                 }
             } else if (prevContent.membership === "ban") {
-                return _t('%(senderName)s unbanned %(targetName)s.', {senderName, targetName});
+                return () => _t('%(senderName)s unbanned %(targetName)s.', {senderName, targetName});
             } else if (prevContent.membership === "invite") {
-                return _t('%(senderName)s withdrew %(targetName)s\'s invitation.', {
+                return () => _t('%(senderName)s withdrew %(targetName)s\'s invitation.', {
                     senderName,
                     targetName,
-                }) + ' ' + reason;
+                }) + ' ' + getReason();
             } else if (prevContent.membership === "join") {
-                return _t('%(senderName)s kicked %(targetName)s.', {senderName, targetName}) + ' ' + reason;
+                return () => _t('%(senderName)s kicked %(targetName)s.', {senderName, targetName}) + ' ' + getReason();
             } else {
-                return "";
+                return null;
             }
     }
 }
 
 function textForTopicEvent(ev) {
     const senderDisplayName = ev.sender && ev.sender.name ? ev.sender.name : ev.getSender();
-    return _t('%(senderDisplayName)s changed the topic to "%(topic)s".', {
+    return () => _t('%(senderDisplayName)s changed the topic to "%(topic)s".', {
         senderDisplayName,
         topic: ev.getContent().topic,
     });
@@ -115,16 +119,16 @@ function textForRoomNameEvent(ev) {
     const senderDisplayName = ev.sender && ev.sender.name ? ev.sender.name : ev.getSender();
 
     if (!ev.getContent().name || ev.getContent().name.trim().length === 0) {
-        return _t('%(senderDisplayName)s removed the room name.', {senderDisplayName});
+        return () => _t('%(senderDisplayName)s removed the room name.', {senderDisplayName});
     }
     if (ev.getPrevContent().name) {
-        return _t('%(senderDisplayName)s changed the room name from %(oldRoomName)s to %(newRoomName)s.', {
+        return () => _t('%(senderDisplayName)s changed the room name from %(oldRoomName)s to %(newRoomName)s.', {
             senderDisplayName,
             oldRoomName: ev.getPrevContent().name,
             newRoomName: ev.getContent().name,
         });
     }
-    return _t('%(senderDisplayName)s changed the room name to %(roomName)s.', {
+    return () => _t('%(senderDisplayName)s changed the room name to %(roomName)s.', {
         senderDisplayName,
         roomName: ev.getContent().name,
     });
@@ -132,19 +136,23 @@ function textForRoomNameEvent(ev) {
 
 function textForTombstoneEvent(ev) {
     const senderDisplayName = ev.sender && ev.sender.name ? ev.sender.name : ev.getSender();
-    return _t('%(senderDisplayName)s upgraded this room.', {senderDisplayName});
+    return () => _t('%(senderDisplayName)s upgraded this room.', {senderDisplayName});
 }
 
 function textForJoinRulesEvent(ev) {
     const senderDisplayName = ev.sender && ev.sender.name ? ev.sender.name : ev.getSender();
     switch (ev.getContent().join_rule) {
         case "public":
-            return _t('%(senderDisplayName)s made the room public to whoever knows the link.', {senderDisplayName});
+            return () => _t('%(senderDisplayName)s made the room public to whoever knows the link.', {
+                senderDisplayName,
+            });
         case "invite":
-            return _t('%(senderDisplayName)s made the room invite only.', {senderDisplayName});
+            return () => _t('%(senderDisplayName)s made the room invite only.', {
+                senderDisplayName,
+            });
         default:
             // The spec supports "knock" and "private", however nothing implements these.
-            return _t('%(senderDisplayName)s changed the join rule to %(rule)s', {
+            return () => _t('%(senderDisplayName)s changed the join rule to %(rule)s', {
                 senderDisplayName,
                 rule: ev.getContent().join_rule,
             });
@@ -155,12 +163,12 @@ function textForGuestAccessEvent(ev) {
     const senderDisplayName = ev.sender && ev.sender.name ? ev.sender.name : ev.getSender();
     switch (ev.getContent().guest_access) {
         case "can_join":
-            return _t('%(senderDisplayName)s has allowed guests to join the room.', {senderDisplayName});
+            return () => _t('%(senderDisplayName)s has allowed guests to join the room.', {senderDisplayName});
         case "forbidden":
-            return _t('%(senderDisplayName)s has prevented guests from joining the room.', {senderDisplayName});
+            return () => _t('%(senderDisplayName)s has prevented guests from joining the room.', {senderDisplayName});
         default:
             // There's no other options we can expect, however just for safety's sake we'll do this.
-            return _t('%(senderDisplayName)s changed guest access to %(rule)s', {
+            return () => _t('%(senderDisplayName)s changed guest access to %(rule)s', {
                 senderDisplayName,
                 rule: ev.getContent().guest_access,
             });
@@ -175,17 +183,17 @@ function textForRelatedGroupsEvent(ev) {
     const removed = prevGroups.filter((g) => !groups.includes(g));
 
     if (added.length && !removed.length) {
-        return _t('%(senderDisplayName)s enabled flair for %(groups)s in this room.', {
+        return () => _t('%(senderDisplayName)s enabled flair for %(groups)s in this room.', {
             senderDisplayName,
             groups: added.join(', '),
         });
     } else if (!added.length && removed.length) {
-        return _t('%(senderDisplayName)s disabled flair for %(groups)s in this room.', {
+        return () => _t('%(senderDisplayName)s disabled flair for %(groups)s in this room.', {
             senderDisplayName,
             groups: removed.join(', '),
         });
     } else if (added.length && removed.length) {
-        return _t('%(senderDisplayName)s enabled flair for %(newGroups)s and disabled flair for ' +
+        return () => _t('%(senderDisplayName)s enabled flair for %(newGroups)s and disabled flair for ' +
             '%(oldGroups)s in this room.', {
             senderDisplayName,
             newGroups: added.join(', '),
@@ -193,7 +201,7 @@ function textForRelatedGroupsEvent(ev) {
         });
     } else {
         // Don't bother rendering this change (because there were no changes)
-        return '';
+        return null;
     }
 }
 
@@ -207,11 +215,11 @@ function textForServerACLEvent(ev) {
         allow_ip_literals: !(prevContent.allow_ip_literals === false),
     };
 
-    let text = "";
+    let getText = null;
     if (prev.deny.length === 0 && prev.allow.length === 0) {
-        text = _t("%(senderDisplayName)s set the server ACLs for this room.", {senderDisplayName});
+        getText = () => _t("%(senderDisplayName)s set the server ACLs for this room.", {senderDisplayName});
     } else {
-        text = _t("%(senderDisplayName)s changed the server ACLs for this room.", {senderDisplayName});
+        getText = () => _t("%(senderDisplayName)s changed the server ACLs for this room.", {senderDisplayName});
     }
 
     if (!Array.isArray(current.allow)) {
@@ -220,13 +228,15 @@ function textForServerACLEvent(ev) {
 
     // If we know for sure everyone is banned, mark the room as obliterated
     if (current.allow.length === 0) {
-        return text + " " + _t("🎉 All servers are banned from participating! This room can no longer be used.");
+        return () => getText() + " " +
+            _t("🎉 All servers are banned from participating! This room can no longer be used.");
     }
 
-    return text;
+    return getText;
 }
 
 function textForMessageEvent(ev) {
+    return () => {
         const senderDisplayName = ev.sender && ev.sender.name ? ev.sender.name : ev.getSender();
         let message = senderDisplayName + ': ' + ev.getContent().body;
         if (ev.getContent().msgtype === "m.emote") {
@@ -235,6 +245,7 @@ function textForMessageEvent(ev) {
             message = _t('%(senderDisplayName)s sent an image.', {senderDisplayName});
         }
         return message;
+    };
 }
 
 function textForCanonicalAliasEvent(ev) {
@@ -248,96 +259,100 @@ function textForCanonicalAliasEvent(ev) {
 
     if (!removedAltAliases.length && !addedAltAliases.length) {
         if (newAlias) {
-            return _t('%(senderName)s set the main address for this room to %(address)s.', {
+            return () => _t('%(senderName)s set the main address for this room to %(address)s.', {
                 senderName: senderName,
                 address: ev.getContent().alias,
             });
         } else if (oldAlias) {
-            return _t('%(senderName)s removed the main address for this room.', {
+            return () => _t('%(senderName)s removed the main address for this room.', {
                 senderName: senderName,
             });
         }
     } else if (newAlias === oldAlias) {
         if (addedAltAliases.length && !removedAltAliases.length) {
-            return _t('%(senderName)s added the alternative addresses %(addresses)s for this room.', {
+            return () => _t('%(senderName)s added the alternative addresses %(addresses)s for this room.', {
                 senderName: senderName,
                 addresses: addedAltAliases.join(", "),
                 count: addedAltAliases.length,
             });
         } if (removedAltAliases.length && !addedAltAliases.length) {
-            return _t('%(senderName)s removed the alternative addresses %(addresses)s for this room.', {
+            return () => _t('%(senderName)s removed the alternative addresses %(addresses)s for this room.', {
                 senderName: senderName,
                 addresses: removedAltAliases.join(", "),
                 count: removedAltAliases.length,
             });
         } if (removedAltAliases.length && addedAltAliases.length) {
-            return _t('%(senderName)s changed the alternative addresses for this room.', {
+            return () => _t('%(senderName)s changed the alternative addresses for this room.', {
                 senderName: senderName,
             });
         }
     } else {
         // both alias and alt_aliases where modified
-        return _t('%(senderName)s changed the main and alternative addresses for this room.', {
+        return () => _t('%(senderName)s changed the main and alternative addresses for this room.', {
             senderName: senderName,
         });
     }
     // in case there is no difference between the two events,
     // say something as we can't simply hide the tile from here
-    return _t('%(senderName)s changed the addresses for this room.', {
+    return () => _t('%(senderName)s changed the addresses for this room.', {
         senderName: senderName,
     });
 }
 
 function textForCallAnswerEvent(event) {
+    return () => {
         const senderName = event.sender ? event.sender.name : _t('Someone');
         const supported = MatrixClientPeg.get().supportsVoip() ? '' : _t('(not supported by this browser)');
         return _t('%(senderName)s answered the call.', {senderName}) + ' ' + supported;
+    };
 }
 
 function textForCallHangupEvent(event) {
-    const senderName = event.sender ? event.sender.name : _t('Someone');
+    const getSenderName = () => event.sender ? event.sender.name : _t('Someone');
     const eventContent = event.getContent();
-    let reason = "";
+    let getReason = () => "";
     if (!MatrixClientPeg.get().supportsVoip()) {
-        reason = _t('(not supported by this browser)');
+        getReason = () => _t('(not supported by this browser)');
     } else if (eventContent.reason) {
         if (eventContent.reason === "ice_failed") {
             // We couldn't establish a connection at all
-            reason = _t('(could not connect media)');
+            getReason = () => _t('(could not connect media)');
         } else if (eventContent.reason === "ice_timeout") {
             // We established a connection but it died
-            reason = _t('(connection failed)');
+            getReason = () => _t('(connection failed)');
         } else if (eventContent.reason === "user_media_failed") {
             // The other side couldn't open capture devices
-            reason = _t("(their device couldn't start the camera / microphone)");
+            getReason = () => _t("(their device couldn't start the camera / microphone)");
         } else if (eventContent.reason === "unknown_error") {
             // An error code the other side doesn't have a way to express
             // (as opposed to an error code they gave but we don't know about,
             // in which case we show the error code)
-            reason = _t("(an error occurred)");
+            getReason = () => _t("(an error occurred)");
         } else if (eventContent.reason === "invite_timeout") {
-            reason = _t('(no answer)');
+            getReason = () => _t('(no answer)');
         } else if (eventContent.reason === "user hangup" || eventContent.reason === "user_hangup") {
             // workaround for https://github.com/vector-im/element-web/issues/5178
             // it seems Android randomly sets a reason of "user hangup" which is
             // interpreted as an error code :(
             // https://github.com/vector-im/riot-android/issues/2623
             // Also the correct hangup code as of VoIP v1 (with underscore)
-            reason = '';
+            getReason = () => '';
         } else {
-            reason = _t('(unknown failure: %(reason)s)', {reason: eventContent.reason});
+            getReason = () => _t('(unknown failure: %(reason)s)', {reason: eventContent.reason});
         }
     }
-    return _t('%(senderName)s ended the call.', {senderName}) + ' ' + reason;
+    return () => _t('%(senderName)s ended the call.', {senderName: getSenderName()}) + ' ' + getReason();
 }
 
 function textForCallRejectEvent(event) {
+    return () => {
         const senderName = event.sender ? event.sender.name : _t('Someone');
         return _t('%(senderName)s declined the call.', {senderName});
+    };
 }
 
 function textForCallInviteEvent(event) {
-    const senderName = event.sender ? event.sender.name : _t('Someone');
+    const getSenderName = () => event.sender ? event.sender.name : _t('Someone');
     // FIXME: Find a better way to determine this from the event?
     let isVoice = true;
     if (event.getContent().offer && event.getContent().offer.sdp &&
@@ -350,13 +365,21 @@ function textForCallInviteEvent(event) {
     // can have a hard time translating those strings. In an effort to make translations easier
     // and more accurate, we break out the string-based variables to a couple booleans.
     if (isVoice && isSupported) {
-        return _t("%(senderName)s placed a voice call.", {senderName});
+        return () => _t("%(senderName)s placed a voice call.", {
+            senderName: getSenderName(),
+        });
     } else if (isVoice && !isSupported) {
-        return _t("%(senderName)s placed a voice call. (not supported by this browser)", {senderName});
+        return () => _t("%(senderName)s placed a voice call. (not supported by this browser)", {
+            senderName: getSenderName(),
+        });
     } else if (!isVoice && isSupported) {
-        return _t("%(senderName)s placed a video call.", {senderName});
+        return () => _t("%(senderName)s placed a video call.", {
+            senderName: getSenderName(),
+        });
     } else if (!isVoice && !isSupported) {
-        return _t("%(senderName)s placed a video call. (not supported by this browser)", {senderName});
+        return () => _t("%(senderName)s placed a video call. (not supported by this browser)", {
+            senderName: getSenderName(),
+        });
     }
 }
 
@@ -364,14 +387,13 @@ function textForThreePidInviteEvent(event) {
     const senderName = event.sender ? event.sender.name : event.getSender();
 
     if (!isValid3pidInvite(event)) {
-        const targetDisplayName = event.getPrevContent().display_name || _t("Someone");
+        return () => _t('%(senderName)s revoked the invitation for %(targetDisplayName)s to join the room.', {
-        return _t('%(senderName)s revoked the invitation for %(targetDisplayName)s to join the room.', {
             senderName,
-            targetDisplayName,
+            targetDisplayName: event.getPrevContent().display_name || _t("Someone"),
         });
     }
 
-    return _t('%(senderName)s sent an invitation to %(targetDisplayName)s to join the room.', {
+    return () => _t('%(senderName)s sent an invitation to %(targetDisplayName)s to join the room.', {
         senderName,
         targetDisplayName: event.getContent().display_name,
     });
@@ -381,17 +403,17 @@ function textForHistoryVisibilityEvent(event) {
     const senderName = event.sender ? event.sender.name : event.getSender();
     switch (event.getContent().history_visibility) {
         case 'invited':
-            return _t('%(senderName)s made future room history visible to all room members, '
+            return () => _t('%(senderName)s made future room history visible to all room members, '
                 + 'from the point they are invited.', {senderName});
         case 'joined':
-            return _t('%(senderName)s made future room history visible to all room members, '
+            return () => _t('%(senderName)s made future room history visible to all room members, '
                 + 'from the point they joined.', {senderName});
         case 'shared':
-            return _t('%(senderName)s made future room history visible to all room members.', {senderName});
+            return () => _t('%(senderName)s made future room history visible to all room members.', {senderName});
         case 'world_readable':
-            return _t('%(senderName)s made future room history visible to anyone.', {senderName});
+            return () => _t('%(senderName)s made future room history visible to anyone.', {senderName});
         default:
-            return _t('%(senderName)s made future room history visible to unknown (%(visibility)s).', {
+            return () => _t('%(senderName)s made future room history visible to unknown (%(visibility)s).', {
                 senderName,
                 visibility: event.getContent().history_visibility,
             });
@@ -403,7 +425,7 @@ function textForPowerEvent(event) {
     const senderName = event.sender ? event.sender.name : event.getSender();
     if (!event.getPrevContent() || !event.getPrevContent().users ||
         !event.getContent() || !event.getContent().users) {
-        return '';
+        return null;
     }
     const userDefault = event.getContent().users_default || 0;
     // Construct set of userIds
@@ -418,35 +440,35 @@ function textForPowerEvent(event) {
             if (users.indexOf(userId) === -1) users.push(userId);
         },
     );
-    const diff = [];
+    const diffs = [];
-    // XXX: This is also surely broken for i18n
     users.forEach((userId) => {
         // Previous power level
         const from = event.getPrevContent().users[userId];
         // Current power level
         const to = event.getContent().users[userId];
         if (to !== from) {
-            diff.push(
+            diffs.push({ userId, from, to });
-                _t('%(userId)s from %(fromPowerLevel)s to %(toPowerLevel)s', {
-                    userId,
-                    fromPowerLevel: Roles.textualPowerLevel(from, userDefault),
-                    toPowerLevel: Roles.textualPowerLevel(to, userDefault),
-                }),
-            );
         }
     });
-    if (!diff.length) {
+    if (!diffs.length) {
-        return '';
+        return null;
     }
-    return _t('%(senderName)s changed the power level of %(powerLevelDiffText)s.', {
+    // XXX: This is also surely broken for i18n
+    return () => _t('%(senderName)s changed the power level of %(powerLevelDiffText)s.', {
         senderName,
-        powerLevelDiffText: diff.join(", "),
+        powerLevelDiffText: diffs.map(diff =>
+            _t('%(userId)s from %(fromPowerLevel)s to %(toPowerLevel)s', {
+                userId: diff.userId,
+                fromPowerLevel: Roles.textualPowerLevel(diff.from, userDefault),
+                toPowerLevel: Roles.textualPowerLevel(diff.to, userDefault),
+            }),
+        ).join(", "),
     });
 }
 
 function textForPinnedEvent(event) {
     const senderName = event.sender ? event.sender.name : event.getSender();
-    return _t("%(senderName)s changed the pinned messages for the room.", {senderName});
+    return () => _t("%(senderName)s changed the pinned messages for the room.", {senderName});
 }
 
 function textForWidgetEvent(event) {
@@ -464,16 +486,16 @@ function textForWidgetEvent(event) {
     // equivalent to that condition.
     if (url) {
         if (prevUrl) {
-            return _t('%(widgetName)s widget modified by %(senderName)s', {
+            return () => _t('%(widgetName)s widget modified by %(senderName)s', {
                 widgetName, senderName,
             });
         } else {
-            return _t('%(widgetName)s widget added by %(senderName)s', {
+            return () => _t('%(widgetName)s widget added by %(senderName)s', {
                 widgetName, senderName,
             });
         }
     } else {
-        return _t('%(widgetName)s widget removed by %(senderName)s', {
+        return () => _t('%(widgetName)s widget removed by %(senderName)s', {
             widgetName, senderName,
         });
     }
@@ -481,7 +503,7 @@ function textForWidgetEvent(event) {
 
 function textForWidgetLayoutEvent(event) {
     const senderName = event.sender?.name || event.getSender();
-    return _t("%(senderName)s has updated the widget layout", {senderName});
+    return () => _t("%(senderName)s has updated the widget layout", {senderName});
 }
 
 function textForMjolnirEvent(event) {
@@ -492,74 +514,74 @@ function textForMjolnirEvent(event) {
     // Rule removed
     if (!entity) {
         if (USER_RULE_TYPES.includes(event.getType())) {
-            return _t("%(senderName)s removed the rule banning users matching %(glob)s",
+            return () => _t("%(senderName)s removed the rule banning users matching %(glob)s",
                 {senderName, glob: prevEntity});
         } else if (ROOM_RULE_TYPES.includes(event.getType())) {
-            return _t("%(senderName)s removed the rule banning rooms matching %(glob)s",
+            return () => _t("%(senderName)s removed the rule banning rooms matching %(glob)s",
                 {senderName, glob: prevEntity});
         } else if (SERVER_RULE_TYPES.includes(event.getType())) {
-            return _t("%(senderName)s removed the rule banning servers matching %(glob)s",
+            return () => _t("%(senderName)s removed the rule banning servers matching %(glob)s",
                 {senderName, glob: prevEntity});
         }
 
         // Unknown type. We'll say something, but we shouldn't end up here.
-        return _t("%(senderName)s removed a ban rule matching %(glob)s", {senderName, glob: prevEntity});
+        return () => _t("%(senderName)s removed a ban rule matching %(glob)s", {senderName, glob: prevEntity});
     }
 
     // Invalid rule
-    if (!recommendation || !reason) return _t(`%(senderName)s updated an invalid ban rule`, {senderName});
+    if (!recommendation || !reason) return () => _t(`%(senderName)s updated an invalid ban rule`, {senderName});
 
     // Rule updated
     if (entity === prevEntity) {
         if (USER_RULE_TYPES.includes(event.getType())) {
-            return _t("%(senderName)s updated the rule banning users matching %(glob)s for %(reason)s",
+            return () => _t("%(senderName)s updated the rule banning users matching %(glob)s for %(reason)s",
                 {senderName, glob: entity, reason});
         } else if (ROOM_RULE_TYPES.includes(event.getType())) {
-            return _t("%(senderName)s updated the rule banning rooms matching %(glob)s for %(reason)s",
+            return () => _t("%(senderName)s updated the rule banning rooms matching %(glob)s for %(reason)s",
                 {senderName, glob: entity, reason});
         } else if (SERVER_RULE_TYPES.includes(event.getType())) {
-            return _t("%(senderName)s updated the rule banning servers matching %(glob)s for %(reason)s",
+            return () => _t("%(senderName)s updated the rule banning servers matching %(glob)s for %(reason)s",
                 {senderName, glob: entity, reason});
         }
 
         // Unknown type. We'll say something but we shouldn't end up here.
-        return _t("%(senderName)s updated a ban rule matching %(glob)s for %(reason)s",
+        return () => _t("%(senderName)s updated a ban rule matching %(glob)s for %(reason)s",
             {senderName, glob: entity, reason});
     }
 
     // New rule
     if (!prevEntity) {
         if (USER_RULE_TYPES.includes(event.getType())) {
-            return _t("%(senderName)s created a rule banning users matching %(glob)s for %(reason)s",
+            return () => _t("%(senderName)s created a rule banning users matching %(glob)s for %(reason)s",
                 {senderName, glob: entity, reason});
         } else if (ROOM_RULE_TYPES.includes(event.getType())) {
-            return _t("%(senderName)s created a rule banning rooms matching %(glob)s for %(reason)s",
+            return () => _t("%(senderName)s created a rule banning rooms matching %(glob)s for %(reason)s",
                 {senderName, glob: entity, reason});
         } else if (SERVER_RULE_TYPES.includes(event.getType())) {
-            return _t("%(senderName)s created a rule banning servers matching %(glob)s for %(reason)s",
+            return () => _t("%(senderName)s created a rule banning servers matching %(glob)s for %(reason)s",
                 {senderName, glob: entity, reason});
         }
 
         // Unknown type. We'll say something but we shouldn't end up here.
-        return _t("%(senderName)s created a ban rule matching %(glob)s for %(reason)s",
+        return () => _t("%(senderName)s created a ban rule matching %(glob)s for %(reason)s",
             {senderName, glob: entity, reason});
     }
 
     // else the entity !== prevEntity - count as a removal & add
     if (USER_RULE_TYPES.includes(event.getType())) {
-        return _t(
+        return () => _t(
             "%(senderName)s changed a rule that was banning users matching %(oldGlob)s to matching " +
             "%(newGlob)s for %(reason)s",
             {senderName, oldGlob: prevEntity, newGlob: entity, reason},
         );
     } else if (ROOM_RULE_TYPES.includes(event.getType())) {
-        return _t(
+        return () => _t(
             "%(senderName)s changed a rule that was banning rooms matching %(oldGlob)s to matching " +
             "%(newGlob)s for %(reason)s",
             {senderName, oldGlob: prevEntity, newGlob: entity, reason},
         );
     } else if (SERVER_RULE_TYPES.includes(event.getType())) {
-        return _t(
+        return () => _t(
             "%(senderName)s changed a rule that was banning servers matching %(oldGlob)s to matching " +
             "%(newGlob)s for %(reason)s",
             {senderName, oldGlob: prevEntity, newGlob: entity, reason},
@@ -567,7 +589,7 @@ function textForMjolnirEvent(event) {
     }
 
     // Unknown type. We'll say something but we shouldn't end up here.
-    return _t("%(senderName)s updated a ban rule that was matching %(oldGlob)s to matching %(newGlob)s " +
+    return () => _t("%(senderName)s updated a ban rule that was matching %(oldGlob)s to matching %(newGlob)s " +
         "for %(reason)s", {senderName, oldGlob: prevEntity, newGlob: entity, reason});
 }
 
@@ -604,8 +626,12 @@ for (const evType of ALL_RULE_TYPES) {
     stateHandlers[evType] = textForMjolnirEvent;
 }
 
+export function hasText(ev) {
+    const handler = (ev.isState() ? stateHandlers : handlers)[ev.getType()];
+    return Boolean(handler?.(ev));
+}
+
 export function textForEvent(ev) {
     const handler = (ev.isState() ? stateHandlers : handlers)[ev.getType()];
-    if (handler) return handler(ev);
+    return handler?.(ev)?.() || '';
-    return '';
 }

src/components/structures/MessagePanel.js

@@ -30,7 +30,7 @@ import RoomContext from "../../contexts/RoomContext";
 import {Layout, LayoutPropType} from "../../settings/Layout";
 import {_t} from "../../languageHandler";
 import {haveTileForEvent} from "../views/rooms/EventTile";
-import {textForEvent} from "../../TextForEvent";
+import {hasText} from "../../TextForEvent";
 import IRCTimelineProfileResizer from "../views/elements/IRCTimelineProfileResizer";
 import DMRoomMap from "../../utils/DMRoomMap";
 import NewRoomIntro from "../views/rooms/NewRoomIntro";
@@ -1180,11 +1180,8 @@ class MemberGrouper {
 
     add(ev) {
         if (ev.getType() === 'm.room.member') {
-            // We'll just double check that it's worth our time to do so, through an
+            // We can ignore any events that don't actually have a message to display
-            // ugly hack. If textForEvent returns something, we should group it for
+            if (!hasText(ev)) return;
-            // rendering but if it doesn't then we'll exclude it.
-            const renderText = textForEvent(ev);
-            if (!renderText || renderText.trim().length === 0) return; // quietly ignore
         }
         this.readMarker = this.readMarker || this.panel._readMarkerForEvent(
             ev.getId(),

src/components/views/rooms/EventTile.tsx

@@ -25,7 +25,7 @@ import { RoomMember } from "matrix-js-sdk/src/models/room-member";
 
 import ReplyThread from "../elements/ReplyThread";
 import { _t } from '../../../languageHandler';
-import * as TextForEvent from "../../../TextForEvent";
+import { hasText } from "../../../TextForEvent";
 import * as sdk from "../../../index";
 import dis from '../../../dispatcher/dispatcher';
 import SettingsStore from "../../../settings/SettingsStore";
@@ -1200,7 +1200,7 @@ export function haveTileForEvent(e) {
     const handler = getHandlerTile(e);
     if (handler === undefined) return false;
     if (handler === 'messages.TextualEvent') {
-        return TextForEvent.textForEvent(e) !== '';
+        return hasText(e);
     } else if (handler === 'messages.RoomCreate') {
         return Boolean(e.getContent()['predecessor']);
     } else {