Code Library

1. 19 December, 2022

   Rounding to the nearest multiple of a number

   javascriptcode-library

   const round = (number, step) => {
     return Math.round(number / step) * step;
   };

2. 13 December, 2022

   Exposing child component state in Svelte

   code-libraryjavascript

   <script>
     import {onMount, createEventDispatcher} from 'svelte';
     export let $foo = 0;
   
     const dispatch = createEventDispatcher();
   
     onMount(() => {
      const t = setTimeout(() => {
        foo++;
        dispatch("fooupdate", foo)
      }, 100);
      return (() => {
        clearTimeout(t)
      });
     });
   </script>

3. 29 November, 2022

   Ignoring superseded function calls

   code-libraryjavascripttypescript

   export const latest = <A extends Array<unknown>, T>(fn: (...args: A) => Promise<T>) => {
     let invocationId: object;
   
     return async (...args: A) => {
       const thisInvocationId = (invocationId = new Object());
       const result = await fn(...args);
   
       if (invocationId !== thisInvocationId) {
         throw new Error('Function invocation superseded', { cause: 'SUPERSEDED' });
       }
       return result;
     };
   };

4. 18 November, 2022

   How to kill a service worker

   code-libraryjavascript

   self.addEventListener('install', () => self.skipWaiting());
   self.addEventListener('activate', () =>
     self.registration
       .unregister()
       .then(() => self.clients.matchAll())
       .then((clients) => clients.forEach((client) => client.navigate(client.url)))
   );