I need to get unique random number in javascript (or Typescript).

At this moment I use this code:

```
var id = -((new Date()).getTime() & 0xffff);

```

It returns me numbers like `-13915` or `-28806` ...

It works most of the time but I am having problems when this code is executed in promises (so nearly multiple times at the same time). Then sometimes I got two identical id.

Is there any solution to get unique random numbers in any case ?