channel: Remove an unknown-role check that should be a no-op

Author: chrisbobbe

lib/model/channel.dart

@@ -212,9 +212,9 @@ mixin ChannelStore on UserStore {
   }) {
     assert(inChannel.channelPostPolicy != null);
     final role = selfUser.role;
-    // We let the users with [unknown] role to send the message, then the server
-    // will decide to accept it or not based on its actual role.
-    if (role == UserRole.unknown) return true;
+
+    // (Could early-return true on [UserRole.unknown],
+    // but pre-333 servers shouldn't be giving us an unknown role.)
 
     switch (inChannel.channelPostPolicy!) {
       case ChannelPostPolicy.any:             return true;

test/model/channel_test.dart

@@ -486,32 +486,27 @@ void main() {
 
   group('selfCanSendMessage, legacy', () {
     final testCases = [
-      (ChannelPostPolicy.unknown,        UserRole.unknown,       true),
       (ChannelPostPolicy.unknown,        UserRole.guest,         true),
       (ChannelPostPolicy.unknown,        UserRole.member,        true),
       (ChannelPostPolicy.unknown,        UserRole.moderator,     true),
       (ChannelPostPolicy.unknown,        UserRole.administrator, true),
       (ChannelPostPolicy.unknown,        UserRole.owner,         true),
-      (ChannelPostPolicy.any,            UserRole.unknown,       true),
       (ChannelPostPolicy.any,            UserRole.guest,         true),
       (ChannelPostPolicy.any,            UserRole.member,        true),
       (ChannelPostPolicy.any,            UserRole.moderator,     true),
       (ChannelPostPolicy.any,            UserRole.administrator, true),
       (ChannelPostPolicy.any,            UserRole.owner,         true),
-      (ChannelPostPolicy.fullMembers,    UserRole.unknown,       true),
       (ChannelPostPolicy.fullMembers,    UserRole.guest,         false),
       // The fullMembers/member case gets its own tests further below.
       // (ChannelPostPolicy.fullMembers,    UserRole.member,        /* complicated */),
       (ChannelPostPolicy.fullMembers,    UserRole.moderator,     true),
       (ChannelPostPolicy.fullMembers,    UserRole.administrator, true),
       (ChannelPostPolicy.fullMembers,    UserRole.owner,         true),
-      (ChannelPostPolicy.moderators,     UserRole.unknown,       true),
       (ChannelPostPolicy.moderators,     UserRole.guest,         false),
       (ChannelPostPolicy.moderators,     UserRole.member,        false),
       (ChannelPostPolicy.moderators,     UserRole.moderator,     true),
       (ChannelPostPolicy.moderators,     UserRole.administrator, true),
       (ChannelPostPolicy.moderators,     UserRole.owner,         true),
-      (ChannelPostPolicy.administrators, UserRole.unknown,       true),
       (ChannelPostPolicy.administrators, UserRole.guest,         false),
       (ChannelPostPolicy.administrators, UserRole.member,        false),
       (ChannelPostPolicy.administrators, UserRole.moderator,     false),