$store.set() not triggering the fetcher store

[hemandev]

I have a fetcher that has a dependent value on another store.

const [createFetcherStore, createMutatorStore] = nanoquery({
    fetcher: async (...keys: (string | number)[]) => {
      const methodName = keys[0] as keyof Instance['notification'];
      if (methodName === 'get') {
        console.log('page no is...', keys[1]);
        return instance.notification.get({
          pageNo: keys[1] as number,
          limit: 3,
        });
      }
    },
  });
  
  const $currentPage = atom(1);
  const $notificationStore = createFetcherStore<Notification>([
    'get',
    $currentPage,
  ]);

I have a function in vanilla js loadMore()

    const loadMore = async () => {
     $currentPage.set($currentPage.get() + 1);
    };

I am trying to use these in vanilla js using the listen().

But calling loadMore() is not triggering the $notificationStore. Why?
Shouldn't the $currentPage store change trigger the $notificationStore ?

[dkzlv]

Hey there, @hemandev!

The reactivity on the library side works (and it's pretty thoroughly tested as well!). Vanilla or not, all framework libraries essentially wrap .listen with framework-specific memoization, like in @nanostores/react.
And, most probably, it's not a reactivity issue in nanostores as well, as the code that sets the Promise result value is extremely straightforward.

The issue with your code, as I think, lies in what instance.notification.get function returns, but without the actual implementation details I can't point to an exact issue.
Can you try to come up with an isolated reproduction case on Stackblitz?

[hemandev]

Thanks for the quick response @dkzlv.
I was able to spin up a basic repro sandbox here. Would you mind taking a look?
https://codesandbox.io/p/sandbox/silly-chandrasekhar-ng2tkg

My expectation is that the subscribe() will get called with the new todo values on calling loadMore()

[dkzlv]

@hemandev Hm, yeah, the issue is in onNotify hook (if you comment it out and change $todo?.data for $todo.value?.data, all works as expected), but I don't know exactly why. I'll keep the issue open and see what my cause it either in query or in core.

[hemandev]

Yeah, that did fix it.
Unfortunately, I was using onNotify to keep appending all the fetched todos to another store.
Let me see if I can figure another way to do it. Thanks again.

[dkzlv]

@hemandev onSet definitely works.

[hemandev]

I tried with onSet first. But it was not getting triggered always. You can try in the same sandbox.
It calls twice, {loading: false}, {loading: true, data: }` and stops.
It never called the 3rd time with the resolved value.

[dkzlv]

@hemandev Ok, I managed to pinpoint the issue, but I don't know why that happens.

Both onNotify and onSet work, but you need to either use $todo.value in onNotify or destructure newValue from payload in onSet like in this example. For some reason using .get() breaks all of this thing, even though it's basically calling .value.

[hemandev]

Yep, that worked 🎉