test(dtslint): add dtslint test for endWith operator (#4093) (#4175)

Author: dkosasih

spec-dtslint/operators/endWith-spec.ts

@@ -0,0 +1,42 @@
+import { of, asyncScheduler } from 'rxjs';
+import { endWith } from 'rxjs/operators';
+
+it('should support a scheduler', () => {
+  const a = of(1, 2, 3).pipe(endWith(asyncScheduler)); // $ExpectType Observable<number>
+});
+
+it('should infer type for 1 parameter', () => {
+  const a = of(1, 2, 3).pipe(endWith(4)); // $ExpectType Observable<number>
+});
+
+it('should infer type for 2 parameter', () => {
+  const a = of(1, 2, 3).pipe(endWith(4, 5)); // $ExpectType Observable<number>
+});
+
+it('should infer type for 3 parameter', () => {
+  const a = of(1, 2, 3).pipe(endWith(4, 5, 6)); // $ExpectType Observable<number>
+});
+
+it('should infer type for 4 parameter', () => {
+  const a = of(1, 2, 3).pipe(endWith(4, 5, 6, 7)); // $ExpectType Observable<number>
+});
+
+it('should infer type for 5 parameter', () => {
+  const a = of(1, 2, 3).pipe(endWith(4, 5, 6, 7, 8)); // $ExpectType Observable<number>
+});
+
+it('should infer type for 6 parameter', () => {
+  const a = of(1, 2, 3).pipe(endWith(4, 5, 6, 7, 8, 9)); // $ExpectType Observable<number>
+});
+
+it('should infer type for rest parameters', () => {
+  const a = of(1, 2, 3).pipe(endWith(4, 5, 6, 7, 8, 9, 10)); // $ExpectType Observable<number>
+});
+
+it('should accept empty parameter', () => {
+  const a = of(1, 2, 3).pipe(endWith()); // $ExpectType Observable<number>
+});
+
+it('should enforce type', () => {
+  const a = of(1, 2, 3).pipe(endWith('4')); // $ExpectError
+});