PLT-3881 Fix websocket errors after leaving the team (#3815)

api/team.go

@@ -331,6 +331,8 @@ func LeaveTeam(team *model.Team, user *model.User) *model.AppError {
 			if result := <-Srv.Store.Channel().RemoveMember(channel.Id, user.Id); result.Err != nil {
 				return result.Err
 			}
+
+			InvalidateCacheForChannel(channel.Id)
 		}
 	}
 

webapp/actions/websocket_actions.jsx

@@ -194,6 +194,8 @@ function handleLeaveTeamEvent(msg) {
 
         // if the are on the team begin removed redirect them to the root
         if (TeamStore.getCurrentId() === msg.team_id) {
+            TeamStore.setCurrentId('');
+            Client.setTeamId('');
             browserHistory.push('/');
         }
     } else if (TeamStore.getCurrentId() === msg.team_id) {

webapp/stores/team_store.jsx

@@ -63,6 +63,10 @@ class TeamStoreClass extends EventEmitter {
         return this.currentTeamId;
     }
 
+    setCurrentId(id) {
+        this.currentTeamId = id;
+    }
+
     getCurrent() {
         const team = this.teams[this.currentTeamId];