1 import { ObservableInput } from '../types';
2 import { subscribeToArray } from './subscribeToArray';
3 import { subscribeToPromise } from './subscribeToPromise';
4 import { subscribeToIterable } from './subscribeToIterable';
5 import { subscribeToObservable } from './subscribeToObservable';
6 import { isArrayLike } from './isArrayLike';
7 import { isPromise } from './isPromise';
8 import { isObject } from './isObject';
9 import { iterator as Symbol_iterator } from '../symbol/iterator';
10 import { observable as Symbol_observable } from '../symbol/observable';
11 import { Subscription } from '../Subscription';
12 import { Subscriber } from '../Subscriber';
14 export const subscribeTo = <T>(result: ObservableInput<T>): (subscriber: Subscriber<T>) => Subscription | void => {
15 if (!!result && typeof result[Symbol_observable] === 'function') {
16 return subscribeToObservable(result as any);
17 } else if (isArrayLike(result)) {
18 return subscribeToArray(result);
19 } else if (isPromise(result)) {
20 return subscribeToPromise(result as Promise<any>);
21 } else if (!!result && typeof result[Symbol_iterator] === 'function') {
22 return subscribeToIterable(result as any);
24 const value = isObject(result) ? 'an invalid object' : `'${result}'`;
25 const msg = `You provided ${value} where a stream was expected.`
26 + ' You can provide an Observable, Promise, Array, or Iterable.';
27 throw new TypeError(msg);