getHashValue.ts

import { filter, isEmpty, split, startsWith } from 'ramda';

/**
 * Parse the hash string and return the the value for the given name
 * @param fullHash - The value of `$page.url.hash`
 * @param hashName - Name of the hash which comes in `nam=value` format
 * @returns decoded value via `decodeURIComponent`
 */
export function getHashValue(fullHash: string, hashName: string): string {
  console.log('getHashValue', { hashName, fullHash });
  if (isEmpty(fullHash)) return '';

  const parts = split('&')(fullHash.substring(1));

  const foundValue = filter((p) => startsWith(hashName, p), parts);

  if (isEmpty(foundValue)) {
    const message = `${hashName} hash name cannot be found`;
    console.error(message);
    return '';
  } else {
    const foundParts = split('=')(foundValue[0]);
    return decodeURIComponent(foundParts[1]);
  }
}

your-route.svelte

<script context="module">
  export const prerender = true;
</script>

<script script lang="ts">
 /**
   * Websocket server address without the client path.
   */
  let ws: string = 'ws://127.0.0.1:8088';
</script>