Running a Function When an #await Block resolves in Svelte(Kit)

<script>
import Loader from "$components/forms/Helpers/Loader.svelte";

export let data;
// let's say data.myPromise is a promise.
</script>

{#await data.myPromise}
<!-- This is what shows while the promise is pending -->
<Loader />

{:then results}
<!-- Shows this if/when the promise resolves successfully -->
{#each results as result}
<li>{result}</li>
{/each}

{:catch error}
<!-- Shows this if/when the promise rejects -->
<p class="text-red">{error?.message ?? "Something went wrong"}</p>
{/await}

<script>
import { toast } from "svelte-sonner";

/**
* Displays a success toast
* @param {number | string} resultsLength - Number of results
*/
function showSuccess (resultsLength) {
toast.success(`${resultsLength} result${resultsLength > 1 ? "s" : ""} retrieved!`)
}

/**
* Displays an error toast
* @param {string} [errorMessage] - Error message to display
*/
function showError(errorMessage) {
toast.error(`An Error Occured`, {
message: errorMessage ?? "Unknown Error"
})
}

</script>

{#await data.myPromise}
<!-- Displays while the promise is pending -->
<Loader />

{:then results}
<!-- Run showSuccess when the promise resolves -->
{showSuccess(results.length)}

  <!-- Display results -->
{#each results as result}
<li>{result}</li>
{/each}

{:catch error}
<!-- Run (trigger) showError when the promise rejects -->
{showError(error.message)}

  <!-- Display error message -->
<p class="text-red">{error?.message ?? "Something went wrong"}</p>
{/await}

<script>
import { toast } from "svelte-sonner";

/**
* @param {number | string} resultsLength
* @returns {string} - Empty string to avoid display issues
*/
function showSuccess (resultsLength) {
toast.success(`${resultsLength} result${resultsLength > 1 ? "s" : ""} retrieved!`)
return ""; // Return an empty string
}

/**
* @param {string} [errorMessage]
* @returns {string} - Empty string to avoid display issues
*/
function showError(errorMessage) {
toast.error(`An Error Occured`, {
message: errorMessage ?? "Unknown Error"
})
return ""; // Return an empty string
}

</script>

{#await data.myPromise}
  <!-- Display this while the promise is pending -->
<Loader />

{:then results}
<!-- Run showSuccess -->
{showSuccess(results.length)} <!-- Won't render any text in the UI -->

<!-- This shows if/when the promise is resolved -->
{#each results as result}
<li>{result}</li>
{/each}

{:catch error}
<!-- Run showError -->
{showError(error.message)} <!-- Won't render any text in the UI -->

<!-- This shows if/when the promise is rejected -->
<p class="text-red">{error?.message ?? "Something went wrong"}</p>
{/await}

<script>
import { toast } from "svelte-sonner";

/**
* @param {number | string} resultsLength
*/
function showSuccess (resultsLength) {
toast.success(`${resultsLength} result${resultsLength > 1 ? "s" : ""} retrieved!`)
// No explicit return necessary. Returns undefined by default
}

/**
* @param {string} [errorMessage]
* @returns {string}
*/
function showError(errorMessage) {
toast.error(`An Error Occured`, {
message: errorMessage ?? "Unknown Error"
})
// No explicit return necessary. Returns undefined by default
}

</script>

{#await data.myPromise}
  <!-- Display this while the promise is pending -->
<Loader />

{:then results}
<div class="hidden"> <!-- Hide the function block -->
  <!-- Display results -->

{showSuccess(results.length)}
</div>

<!-- This shows if/when the promise is resolved -->
{#each results as result}
<li>{result}</li>
{/each}

{:catch error}
<div class="hidden"><!-- Hide the function call -->
{showError(error.message)}
<div>

<!-- This shows if/when the promise is rejected -->
<p class="text-red">{error?.message ?? "Something went wrong"}</p>
{/await}

<style>
  .hidden {
    display: none;
  }
</style>