chore(repeatWhen): add dtslint tests with deprecation

spec-dtslint/operators/repeatWhen-spec.ts

@@ -0,0 +1,22 @@
+import { of } from 'rxjs';
+import { repeatWhen } from 'rxjs/operators';
+
+it('should infer correctly', () => {
+  const o = of(1, 2, 3).pipe(repeatWhen(errors => errors)); // $ExpectType Observable<number>
+});
+
+it('should infer correctly when the error observable has a different type', () => {
+  const o = of(1, 2, 3).pipe(repeatWhen(repeatWhen(errors => of('a', 'b', 'c')))); // $ExpectType Observable<number>
+});
+
+it('should enforce types', () => {
+  const o = of(1, 2, 3).pipe(repeatWhen()); // $ExpectError
+});
+
+it('should enforce types of the notifier', () => {
+  const o = of(1, 2, 3).pipe(repeatWhen(() => 8)); // $ExpectError
+});
+
+it('should be deprecated', () => {
+  const o = of(1, 2, 3).pipe(repeatWhen(() => of(true))); // $ExpectDeprecation
+});