Chat application built in Angular 6 x AngularFire2 Throwing error

Question

Installed Dependencies

"@angular/cli": "1.6.6"
"angularfire2": "5.0.0-rc.6",
"firebase": "4.12.1",
"rxjs": "^5.5.10",
"rxjs-compat": "^6.3.3",

My imports

import { AngularFireAuth } from 'angularfire2/auth';
import { AngularFireDatabase, FirebaseListObservable } from 'angularfire2/database-deprecated';
import { Observable } from 'rxjs/Observable';
import * as firebase from 'firebase/app';

trying to query the FirebaseDatabase with the following method

getMessages(): FirebaseListObservable<ChatMessage[]> {
   // Query create list binding
   return this.db.list('messages', {
     query: { limitToLast: '25' }
   });
}

Build returns the following error in the console

error TS2345: Argument of type '{ query: { limitToLast: string; }; }' 
is not assignable to parameter of type 'FirebaseListFactoryOpts'.
Types of property 'query' are incompatible.

Type '{ limitToLast: string; }' is not assignable to type 'Query'.
  Property 'endAt' is missing in type '{ limitToLast: string; }'.

Answer 1

Issue solved!

Updated angularFire2 to latest

npm install firebase @angular/fire --save

changed the imports (FirebaseListObservable replaced with AngularFireList)

import { AngularFireDatabase, AngularFireList } from 'angularfire2/database';

Changed timeSent in the interface model file from "Date = new Date()" to "string"

Removed the square brackets

chatMessages: AngularFireList<ChatMessage>;
getMessages(): AngularFireList<ChatMessage> {
  // changed the query since the AngularFireList does it differently.
  return this.db.list('messages', ref => ref.orderByKey().limitToLast(25));
}