New state ignored when reducer returned reference to same state it had received

[mightyiam]

It seems that when a reducer returns not a new object, but a reference to the same object it received, that reduction is ignored and sources.state.stream does not emit. Am I right about this?

I'm OK with this behavior, as long as it is documented. And perhaps a good exception would help there, as well.
"The following reducer returned a reference to the same state object that it had received. That is not supported. Please modify the reducer to return a new state object."

Pull request welcome?

Versions of packages used:

├─┬ @cycle/dom@22.3.0
│ ├── @cycle/run@5.2.0 deduped
├─┬ @cycle/run@5.2.0
├─┬ @cycle/state@1.2.0
│ ├─┬ @cycle/isolate@5.0.0
│ │ ├── @cycle/run@5.2.0 deduped
│ ├── @cycle/run@5.2.0 deduped

[sarimarton]

I disagree with the need for having an exception for this, but a more detailed documentation is of course can't do any harm.

I guess this dropRepeats() is responsible for the behavior:

cyclejs/state/src/StateSource.ts

Line 94 in 243cd25

.compose(dropRepeats())

[jvanbruegge]

Yeah, this is intentional and I also don't think adding a warning is necessary, but it would be nice to document this more explicitly

[mightyiam]

Could you please explain the intention? I can't think of one.