notify also on falsy values

[piever]

On the main branch, the if clause before updating the value on JS will prevent the update when value is "falsy" (0, "", null, etc).

Simplest way to test is to run

using Bonito
obs = Observable(1)
app = App() do session
    evaljs(session, js"""
    $obs.notify(0, true);
    console.log($obs.value)
    """)
end

on main, the console log shows 1 (no update occurred) and on this PR it shows 0.

I wonder whether the idea was to allow obs.notify(), intending to not update the observable and only trigger callbacks but

• that should probably be done with value !== undefined
• on master that also doesn't work, as the julia observable gets updated with nothing.

[SimonDanisch]

Oh wow, good old JS anti-patterns... I feel like there was a reason for this, but can't find any notify() in the code base...

[piever]

(Fixed the new test.)

I feel like there was a reason for this, but can't find any notify() in the code base...

Me nether... But to be honest I'd rather avoid it (and keep the PR as is). AFAIU, javascript would not distinguish between notify() and notify(x.a) for example where the field a is not present (both give value = undefined), which seems error prone... One can always do obs.notify(obs.value) if needed.