test(dtslint): add dtslint tests for windowCount operator (#4093) (#4367

)

* test(dtslint): add dtslint tests for windowCount operator (#4093)

* test(dtslint): add additional dtslint test for windowCount operator (#4093)

spec-dtslint/operators/windowCount-spec.ts

@@ -0,0 +1,16 @@
+import { of } from 'rxjs';
+import { windowCount } from 'rxjs/operators';
+
+it('should infer correctly', () => {
+  of('test').pipe(windowCount(1)); // $ExpectType Observable<Observable<string>>
+  of('test').pipe(windowCount(1, 2)); // $ExpectType Observable<Observable<string>>
+});
+
+it('should enforce windowSize type', () => {
+  of(1).pipe(windowCount()); // $ExpectError
+  of(1).pipe(windowCount('1')); // $ExpectError
+});
+
+it('should enforce startEveryWindow type', () => {
+  of(1).pipe(windowCount(1, '2')); // $ExpectError
+});