Added the consoleObserver;

src/rxjs/console.observer.ts

+import { Observer } from 'rxjs';
+
+let serial = 0;
+
+// tslint:disable:no-console
+export function consoleObserver<T>(subject = `spy#${++serial}`): Observer<T> {
+  return <Observer<T>>{
+    closed: false,
+    next: value => console.log(subject, 'next:', value),
+    error: err => console.log(subject, 'error:', err),
+    complete: () => console.log(subject, 'completed.'),
+  };
+}

src/rxjs/index.ts

@@ -3,3 +3,4 @@ export { safeCombineLatest } from './safe-combine-latest.observable';
 export { safeForkJoin } from './safe-fork-join.observable';
 export { select } from './select.operator';
 export { untilDestroyed } from './until-destroyed.operator';
+export { consoleObserver } from './console.observer';