RepeatWhen in combination Observable.of(x) has unexpected behavior - rxjs5

Question

I am having unexpected behavior with Observable.of() and repeatWhen. I was wondering if this is correct behavior or not, and why?
const value = 5;
let variable = 0;
const getValue = () => {
variable = variable + 1;
return value * variable;
}
function test () {
Observable.of(getValue())
.repeatWhen(obs => obs.delay(1000))
.subscribe(value => console.log(value);
}
Expected: 5 10 15 20 ...
Result: 5 5 5 5 ...
Apparently, the value returned by Observable.of() is reused for each subsequent subscribe. How, why?

Answer 1

The problem is that getValue() is evaluated only once and immediately. That's got nothing to do with rxjs, it's just how Javascript works. You need to evaluate it on each retry instead, which you can do by using defer:
Observable.defer(() => Observable.of(getValue()))
.repeatWhen(obs => obs.delay(1000))
.subscribe(console.log);

Answer 2

The problem is with use of value. You are changing variable not value(also the value is available in two scopes i.e. Global and closer scope).
To solve the issue, Change the definition of getValue as following:
const getValue = () => {
variable = variable + 1;
value = value * variable;
return value;
}
So, corrected code will look like:
const value = 5;
let variable = 0;
const getValue = () => {
variable = variable + 1;
value = value * variable;
return value;
}
function test () {
Observable.of(getValue())
.repeatWhen(obs => obs.delay(1000))
.subscribe(value => console.log(value);
}