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Oleh Baranovskyi obaranovskyi

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@obaranovskyi
obaranovskyi / to-promise.ts
Created December 10, 2021 06:34
import { Observable, Subscriber } from 'rxjs';
const obs = new Observable((subscriber: Subscriber<number>) => {
subscriber.next(1);
subscriber.complete();
});
obs.subscribe(console.log);
@obaranovskyi
obaranovskyi / first-value-from-will-not-wait-for-complete.ts
Created December 10, 2021 06:57
import { firstValueFrom, Observable, Subject } from 'rxjs';
async function demo<T>(observable: Observable<T>): Promise<void> {
const result = await firstValueFrom(observable);
console.log(result);
}
const subject = new Subject();
const obs = subject.asObservable();
@obaranovskyi
obaranovskyi / first-value-from-reject-with-empty-error.ts
Last active December 10, 2021 07:03
import { EmptyError, firstValueFrom, Observable, Subject } from 'rxjs';
async function demo<T>(observable: Observable<T>): Promise<void> {
try {
const result = await firstValueFrom(observable);
console.log(result);
} catch (error) {
console.log(error instanceof EmptyError);
console.error(error);
@obaranovskyi
obaranovskyi / first-value-from-fallback.ts
Created December 10, 2021 07:26
import { firstValueFrom, Observable, Subject } from 'rxjs';
async function demo<T>(observable: Observable<T>): Promise<void> {
try {
const result = await firstValueFrom(observable, { defaultValue: 25 });
console.log(result);
} catch (error) {
console.error(error);
}
@obaranovskyi
obaranovskyi / last-value-from-base-example.ts
Created December 10, 2021 08:46
import { lastValueFrom, Observable, Subject } from 'rxjs';
async function demo<T>(observable: Observable<T>): Promise<void> {
const result = await lastValueFrom(observable);
console.log(result);
}
const subject = new Subject();
demo(subject.asObservable());
@obaranovskyi
obaranovskyi / last-value-from-error.ts
Created December 10, 2021 08:51
import { EmptyError, lastValueFrom, Observable, Subject } from 'rxjs';
async function demo<T>(observable: Observable<T>): Promise<void> {
try {
const promiseResult = await lastValueFrom(observable);
console.log(promiseResult);
} catch (error) {
console.log(error instanceof EmptyError);
console.error(error);
@obaranovskyi
obaranovskyi / last-value-from-default.ts
Created December 10, 2021 08:54
import { EmptyError, lastValueFrom, Observable, Subject } from 'rxjs';
async function demo<T>(observable: Observable<T>): Promise<void> {
try {
const promiseResult = await lastValueFrom(observable, { defaultValue: 25 });
console.log(promiseResult);
} catch (error) {
console.log(error instanceof EmptyError);
console.error(error);
@obaranovskyi
obaranovskyi / from-operator.ts
Created December 10, 2021 09:46
import { from } from 'rxjs';
from(Promise.resolve(2))
.subscribe({
next: console.log,
error: console.error,
complete: () => console.log(`complete`)
});
@obaranovskyi
obaranovskyi / rxjs-works-with-promises.ts
Created December 10, 2021 15:22
import {
combineLatest,
of,
merge,
concat,
exhaustMap,
mergeMap,
concatMap,
forkJoin,
} from 'rxjs';
@obaranovskyi
obaranovskyi / promise-is-hot.ts
Created December 10, 2021 17:11
import { from } from 'rxjs';
const fromPromise$ = from(
new Promise((resolve, reject) => {
console.log('Will be invoked only once, and right away.')
resolve(3);
})
);