A simple utility function to help debugging rxJS observables. This function extends rxjs/Observable namespace and allow to use a function as debug.

main.ts

// main.ts
const debuggerOn = true;

Observable.prototype.debug = function(message: string) {
  return this.do( 
    nextValue => {
      if(debuggerOn) console.log(message, nextValue);
    },
    error => {
      if(debuggerOn) {
        console.error(message, err);
      }
    },
    () => {
      if(debuggerOn) {
        console.log("Observable completed - ");
      }
    }
  );
}

declare module 'rxjs/Observable' {
  interface Observable<T> {
    debug: (...any) => Observable<T>
  }
}