Stay working or quit?

Question

React

So the situation is the following. I got a job as a web developer on react. Naturally I love react, redux, I love flow, jest and I use other libraries from facebook.
Everything seemed to be great.
But! I come to get a job today, and most importantly, after completing all the paperwork, they tell me that the project will be on angular 5, and I should start learning angular. To put it mildly, I was taken aback. No, I'm always happy to learn something new, but having invested so much effort in the facebook ecosystem, I would not want to switch to google so abruptly, but at least complete a couple of some full-fledged projects.
Question. What to do in general?
1. stay and learn Angular, the plus is getting new knowledge
2. pick up the docks and find another job, since even such an attitude that a very important detail was simply hidden already leads to doubts

Answer 1

Learning a new technology at someone else's expense is quite tempting, in my opinion.

Answer 2

It is better to stay at least for the duration of the trial period.
Perhaps you dreamed about Angular, you just didn’t understand it yourself.
Perhaps the company will be so good that you will not care what ecosystem to work in.
If after a couple of weeks you continue to doubt - look for a new job in parallel. Just one Friday you will leave the old one, and on Monday you will go out to the new one.
Well, yes - new knowledge does not hurt. At least as an extension of horizons. And the Angular label in the resume is a definite plus.

Answer 3

1 - change the tags of the question)
I would stay and see how the company generally works. Because there is nothing really terrible in this situation, you, first of all, were taken as a frontend.
If the work processes are well built, the atmosphere is normal, ... - I would learn Angular. Well, this is not jquery)
If you don’t like working in this company, calmly change

Answer 4

Having sufficient experience in the React ecosystem and in general in the frontend, I don’t think it will be extremely difficult to learn something new. I had a similar case, only found out about angular after a couple of months, just getting the project. I advise you to master angular at someone else's expense, a badge will only be a plus, at the same time you can ask for more gold with further employment. You will always have time to change the galley, at the same time while you are mastering angular, look at the situation on the deck.
PS Angular 5 is not Angularjs, so everything is quite good there)