readonly

Deep-freezes value and everything reachable through its enumerable properties, then types the result as DeepReadonly<T>. Useful for exposing config or constants where downstream code shouldn't even attempt to write — a stray write throws a TypeError in strict mode (module code is always strict) rather than mutating the object. Note that freezing affects properties only: the entries of collections like Map and Set live in internal slots, so .set/.add still work on a frozen collection.

Arguments

name	type	description
value	T	value to recursively freeze, in place

Returns: the same value, now frozen and typed DeepReadonly<T>.

Examples

Frozen config

Reads pass through normally; any write throws in strict mode (and TypeScript already flagged it).

import { render, signal } from 'pota'
import { readonly } from 'pota/store'

const settings = readonly({
	api: { url: 'https://api.example.com', timeout: 5000 },
	flags: { betaUI: true },
})

function App() {
	const log = signal('')

	function testWrite() {
		try {
			settings.api.url = '...'
			log.write('write succeeded')
		} catch (e) {
			log.write(`blocked: ${e}`)
		}
	}

	return (
		<div>
			<p>api url: {settings.api.url}</p>
			<button on:click={testWrite}>try to write</button>
			<p>{log.read}</p>
		</div>
	)
}

render(App)