Merge pull request #5415 from aaronraimist/only-member-warning

Warn when you attempt to leave room that you are the only member of

src/components/structures/MatrixChat.tsx

@@ -1096,8 +1096,22 @@ export default class MatrixChat extends React.PureComponent<IProps, IState> {
         const roomToLeave = MatrixClientPeg.get().getRoom(roomId);
         const isSpace = roomToLeave?.isSpaceRoom();
         // Show a warning if there are additional complications.
-        const joinRules = roomToLeave.currentState.getStateEvents('m.room.join_rules', '');
         const warnings = [];
+
+        const memberCount = roomToLeave.currentState.getJoinedMemberCount();
+        if (memberCount === 1) {
+            warnings.push((
+                <span className="warning" key="only_member_warning">
+                    {' '/* Whitespace, otherwise the sentences get smashed together */ }
+                    { _t("You are the only person here. " +
+                        "If you leave, no one will be able to join in the future, including you.") }
+                </span>
+            ));
+
+            return warnings;
+        }
+
+        const joinRules = roomToLeave.currentState.getStateEvents('m.room.join_rules', '');
         if (joinRules) {
             const rule = joinRules.getContent().join_rule;
             if (rule !== "public") {

src/i18n/strings/en_EN.json

@@ -2556,6 +2556,7 @@
     "Failed to reject invitation": "Failed to reject invitation",
     "Cannot create rooms in this community": "Cannot create rooms in this community",
     "You do not have permission to create rooms in this community.": "You do not have permission to create rooms in this community.",
+    "You are the only person here. If you leave, no one will be able to join in the future, including you.": "You are the only person here. If you leave, no one will be able to join in the future, including you.",
     "This space is not public. You will not be able to rejoin without an invite.": "This space is not public. You will not be able to rejoin without an invite.",
     "This room is not public. You will not be able to rejoin without an invite.": "This room is not public. You will not be able to rejoin without an invite.",
     "Are you sure you want to leave the space '%(spaceName)s'?": "Are you sure you want to leave the space '%(spaceName)s'?",