feat(observables): stopPropagation add operator

projects/cdk/observables/stop-propagation.ts

@@ -0,0 +1,8 @@
+import {MonoTypeOperatorFunction} from 'rxjs';
+import {tap} from 'rxjs/operators';
+
+export function stopPropagation<T extends Event>(): MonoTypeOperatorFunction<T> {
+    return tap(e => {
+        e.stopPropagation();
+    });
+}

projects/cdk/observables/test/prevent-default.spec.ts

@@ -0,0 +1,16 @@
+import {fakeAsync} from '@angular/core/testing';
+import {Subject} from 'rxjs';
+import {first} from 'rxjs/operators';
+import {preventDefault} from '../prevent-default';
+
+describe('preventDefault operator function', () => {
+    it('prevents event default behavior', fakeAsync(() => {
+        const event = new Event('click');
+        const subject = new Subject<Event>();
+
+        subject.pipe(preventDefault(), first()).subscribe();
+        subject.next(event);
+
+        expect(event.defaultPrevented).toBe(true);
+    }));
+});

projects/cdk/observables/test/stop-propagation.spec.ts

@@ -0,0 +1,16 @@
+import {fakeAsync} from '@angular/core/testing';
+import {Subject} from 'rxjs';
+import {first} from 'rxjs/operators';
+import {stopPropagation} from '../stop-propagation';
+
+describe('stopPropagation operator function', () => {
+    it('stops event propagation', fakeAsync(() => {
+        const event = new Event('click');
+        const subject = new Subject<Event>();
+
+        subject.pipe(stopPropagation(), first()).subscribe();
+        subject.next(event);
+
+        expect(event.cancelBubble).toBe(true);
+    }));
+});