jquery 3.x ajax does not work async = false

[mariuszkrzaczkowski]

Description

I updated jQuery from 2.2.4 to 3.2.1 and it stopped working properly with ajax parameter async = false.
How can I solve this problem?

[mgol]

Did you read the issue template? It asked for a test case. With such a short report there's nothing we can do.

[mariuszkrzaczkowski]

2.2.4: https://jsfiddle.net/5jmprj0x/
3.2.1: https://jsfiddle.net/4ngd9g4n/1/

The result should be that
1111
2222
33333

[mgol]

This is not the AJAX call that's asynchronous in your example but the invocation of the handler attached via .then(); they're always asynchronous now.

See https://jquery.com/upgrade-guide/3.0/#callback-invocation for more information, in particular:

Another behavior change required for Promises/A+ compliance is that Deferred .then() callbacks are always called asynchronously. Previously, if a .then() callback was added to a Deferred that was already resolved or rejected, the callback would run immediately and synchronously.

[mariuszkrzaczkowski]

Would you help with the improvement of this code?

[mgol]

Synchronous AJAX is generally a bad idea but a quick fix would be to switch from .then to .done.

[mariuszkrzaczkowski]

Thanks, it works