S
SolidJS•4w ago
Amir Hossein Hashemi

Understanding action return values

My understanding is that actions that don't return any value are automatically cleared. When I look at the code, it seems that when an action returns a falsey value, it should also be automatically cleared. However, I don't see this happening in practice. Consider the following code: 
import {
    query,
    action,
    createAsync,
    useAction,
    useSubmission,
} from "@solidjs/router";

let count = 0;

const getCount = query(async () => {
    return count;
}, "getCount");

const increment = action(async () => {
    count += 1;

    if (count === 2) {
        return { error: "Error" };
    }

    return undefined;
});

export default function Home() {
    const c = createAsync(() => getCount());
    const i = useAction(increment);
    const submission = useSubmission(increment);

    return (
        <div>
            <div>Error: {submission.result?.error}</div>
            <div>Count: {c()}</div>
            <button onClick={() => i()}>Add</button>
        </div>
    );
}
import {
    query,
    action,
    createAsync,
    useAction,
    useSubmission,
} from "@solidjs/router";

let count = 0;

const getCount = query(async () => {
    return count;
}, "getCount");

const increment = action(async () => {
    count += 1;

    if (count === 2) {
        return { error: "Error" };
    }

    return undefined;
});

export default function Home() {
    const c = createAsync(() => getCount());
    const i = useAction(increment);
    const submission = useSubmission(increment);

    return (
        <div>
            <div>Error: {submission.result?.error}</div>
            <div>Count: {c()}</div>
            <button onClick={() => i()}>Add</button>
        </div>
    );
}
When the action returns undefined or null, the error is not cleared when the count is incremented, which is expected. However, if it returns 0 or another falsey value, the behavior is different. Am I missing something?
GitHub
solid-router/src/data/action.ts at 30f08665e87829736a9333d55863d279...
A universal router for Solid inspired by Ember and React Router - solidjs/solid-router
2 Replies
ladybluenotes
ladybluenotes•4w ago
@core-team anyone able to answer this? he’s updating the docs
ryansolid
ryansolid•4w ago
Hmm.. I wonder if it is getting serialized in a weird way. No.. this is pure client side example. Returning null/undefined should clear it when it completes. It only keeps things around when they return a value. To be fair there may be a bug here. I think that code probably should be (result != null). Falsey values like false and definitely 0 probably should stick around. But undefined/null definitely should be gone.

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