firebase.d.ts

interface FirebaseQuery {
  /**
   * Listens for data changes at a particular location.
   */
  on(eventType: string, callback: (dataSnapshot: FirebaseDataSnapshot, prevChildName?: string) => void, cancelCallback?: (error: any) => void, context?: Object): (dataSnapshot: FirebaseDataSnapshot, prevChildName?: string) => void;
}

interface Firebase extends FirebaseQuery {
  /**
   * Generates a new child location using a unique name and returns a Firebase reference to it.
   * @returns {Firebase} A Firebase reference for the generated location.
   */
  push(value?: any, onComplete?: (error: any) => void): Firebase;
}

interface FirebaseStatic {
  /**
   * Constructs a new Firebase reference from a full Firebase URL.
   */
  new (firebaseURL: string): Firebase;
}
declare var Firebase: FirebaseStatic;