Counter with LocalStorage - Hyperapp Typing CST Test

Counter with LocalStorage — Hyperapp Code

Counter persists value in localStorage.

import { h, app } from 'https://unpkg.com/hyperapp?module';
const state = { count: parseInt(localStorage.getItem('count')||0), isDark: false };
const actions = {
	increment: () => s => { const count = s.count + 1; localStorage.setItem('count', count); return { count }; },
	decrement: () => s => { const count = s.count - 1; localStorage.setItem('count', count); return { count }; },
	reset: () => s => { localStorage.setItem('count', 0); return { count: 0 }; },
	toggleTheme: () => s => ({ isDark: !s.isDark })
};
const view = (s, a) => (
	h('div', { class: s.isDark ? 'dark-theme' : 'light-theme' }, [
		h('h2', {}, 'Counter: ' + s.count),
		h('div', {}, [
		h('button', { onclick: a.increment }, '+'),
		h('button', { onclick: a.decrement }, '-'),
		h('button', { onclick: a.reset }, 'Reset')
		]),
		h('button', { onclick: a.toggleTheme }, 'Toggle Theme')
	])
);
app({ init: state, view, node: document.body, actions });

Hyperapp Language Guide

Hyperapp is an ultra-lightweight (≈1 KB), functional JavaScript library for building user interfaces using a minimalist architecture of state, actions, and a virtual DOM. It emphasizes simplicity, purity, and predictable UI updates.

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