fix(windowTime): Passing no creation interval will now properly open …

…new window when old one closes

This was a long-broken bit of functionality, but windowTime was so little used, I chose to ignore it. With this change, we could make `bufferTime` based off of `windowTime` and `toArray`.

spec/operators/windowTime-spec.ts

@@ -4,7 +4,7 @@ import { of, Observable } from 'rxjs';
 import { observableMatcher } from '../helpers/observableMatcher';
 
 /** @test {windowTime} */
-describe('windowTime operator', () => {
+describe('windowTime', () => {
   let rxTestScheduler: TestScheduler;
 
   beforeEach(() => {
@@ -32,19 +32,26 @@ describe('windowTime operator', () => {
     });
   });
 
+  // NOTE: This test and behavior were broken in 5.x and 6.x, to where
+  // Not passing a creationInterval would not cause new windows to open
+  // when old ones closed.
   it('should close windows after max count is reached', () => {
     rxTestScheduler.run(({ hot, time, cold, expectObservable, expectSubscriptions }) => {
       const source = hot('--1--2--^--a--b--c--d--e--f--g-----|');
       const subs =               '^--------------------------!';
       const timeSpan = time(     '----------|');
-      //  10 frames              0---------1---------2------|
-      const expected =           'x---------y---------z------|';
-      const x = cold(            '---a--(b|)                  ');
-      const y = cold(                      '--d--(e|)         ');
-      const z = cold(                                '-g-----|');
-      const values = { x, y, z };
-
-      const result = source.pipe(windowTime(timeSpan, null as any, 2, rxTestScheduler));
+      //                          ----------|
+      //                                 ----------|
+      //                                       ----------|
+      //                                             ---------
+      const expected =           'w-----x-----y-----z--------|';
+      const w = cold(            '---a--(b|)                  ');
+      const x = cold(                  '---c--(d|)            ');
+      const y = cold(                        '---e--(f|)      ');
+      const z = cold(                              '---g-----|')
+      const values = { w, x, y, z };
+
+      const result = source.pipe(windowTime(timeSpan, null, 2, rxTestScheduler));
 
       expectObservable(result).toBe(expected, values);
       expectSubscriptions(source.subscriptions).toBe(subs);

src/internal/operators/bufferTime.ts

@@ -90,8 +90,8 @@ export function bufferTime<T>(bufferTimeSpan: number, ...otherArgs: any[]): Oper
   const bufferCreationInterval = (otherArgs[0] as number) ?? null;
   const maxBufferSize = (otherArgs[1] as number) || Infinity;
 
-  return function bufferTimeOperatorFunction(source: Observable<T>) {
-    return lift(source, function (this: Subscriber<T[]>, source: Observable<T>) {
+  return (source: Observable<T>) =>
+    lift(source, function (this: Subscriber<T[]>, source: Observable<T>) {
       const subscriber = this;
       // The active buffers, their related subscriptions, and removal functions.
       let bufferRecords: { buffer: T[]; subs: Subscription; remove: () => void }[] | null = [];
@@ -200,5 +200,4 @@ export function bufferTime<T>(bufferTimeSpan: number, ...otherArgs: any[]): Oper
 
       source.subscribe(bufferTimeSubscriber);
     });
-  };
 }