fix: add delayOnMicrotaskQueue()

projects/s-rxjs-utils/src/lib/operators/delay-on-microtask-queue.spec.ts

@@ -0,0 +1,42 @@
+import { fakeAsync, flushMicrotasks } from "@angular/core/testing";
+import { Subject } from "rxjs";
+import { expectSingleCallAndReset } from "s-ng-dev-utils";
+import {
+  testCompletionPropagation,
+  testErrorPropagation,
+  testUnsubscribePropagation,
+} from "../../test-helpers/misc-helpers";
+import { delayOnMicrotaskQueue } from "./delay-on-microtask-queue";
+
+describe("delayOnMicrotaskQueue()", () => {
+  it("passes along values asynchronously", fakeAsync(() => {
+    const source = new Subject<number>();
+    const spy = jasmine.createSpy();
+    source.pipe(delayOnMicrotaskQueue()).subscribe(spy);
+
+    source.next(1);
+    expect(spy).not.toHaveBeenCalled();
+    flushMicrotasks();
+    expectSingleCallAndReset(spy, 1);
+
+    source.next(2);
+    expect(spy).not.toHaveBeenCalled();
+    flushMicrotasks();
+    expectSingleCallAndReset(spy, 2);
+  }));
+
+  it(
+    "passes along unsubscribes synchronously",
+    testUnsubscribePropagation(delayOnMicrotaskQueue),
+  );
+
+  it(
+    "passes along errors synchronously",
+    testErrorPropagation(delayOnMicrotaskQueue),
+  );
+
+  it(
+    "passes along completion synchronously",
+    testCompletionPropagation(delayOnMicrotaskQueue),
+  );
+});

projects/s-rxjs-utils/src/lib/operators/delay-on-microtask-queue.ts

@@ -0,0 +1,9 @@
+import { asapScheduler } from "rxjs";
+import { delay } from "rxjs/operators";
+
+/**
+ * Delays the emission of items from the source Observable using the microtask queue.
+ */
+export function delayOnMicrotaskQueue() {
+  return delay(0, asapScheduler);
+}

projects/s-rxjs-utils/src/lib/operators/index.ts

@@ -1,4 +1,5 @@
 export { cache } from "./cache";
+export { delayOnMicrotaskQueue } from "./delay-on-microtask-queue";
 export { distinctUntilKeysChanged } from "./distinct-until-keys-changed";
 export { filterBehavior } from "./filter-behavior";
 export { logValues } from "./log-values";

src/app/app.component.ts

@@ -4,6 +4,7 @@ import { Subject } from "rxjs";
 import {
   cache,
   createOperatorFunction,
+  delayOnMicrotaskQueue,
   distinctUntilKeysChanged,
   filterBehavior,
   logValues,
@@ -28,6 +29,7 @@ export class AppComponent {
       new Subject<number>().pipe(
         cache(),
         createOperatorFunction(noop),
+        delayOnMicrotaskQueue(),
         filterBehavior(() => true),
         logValues(),
         skipAfter(new Subject()),