refurbish/index.js

rEFui HMR plugin for Rollup/Vite

import { createFilter } from '@rollup/pluginutils';

const BEGIN = '// ---- BEGIN REFUI HMR INJECT ----';
const END   = '// ----  END REFUI HMR INJECT  ----';

/**
 * @param {object} [options]
 * @param {string|string[]} [options.include]  - picomatch/glob(s) to include (default: jsx,tsx,mdx)
 * @param {string|string[]} [options.exclude]  - patterns to exclude
 * @param {string}          [options.importSource='refui/hmr'] - where to import {setup} from
 * @returns {import('rollup').Plugin}
 */
export function refurbish(options = {}) {
	const {
		include = ['**/*.jsx', '**/*.tsx', '**/*.mdx'],
		exclude,
		importSource = 'refui/hmr'
	} = options;

	const filter = createFilter(include, exclude);

	// pre–serve only for Vite; for plain Rollup we check `command`
	const apply = 'serve';       // Vite hint
	let isBuild = false;         // Rollup flag

	const snippet =
`${BEGIN}
if (import.meta.hot) {
	import('${importSource}').then(({ setup }) =>
		setup({
			url: import.meta.url,
			accept: (cb) => import.meta.hot.accept(cb),
			invalidate: (reason) => {
				if (import.meta.hot.invalidate) {
					import.meta.hot.invalidate(reason);
				} else {
					location.reload();
				}
			}
		})
	);
}
${END}
`;

	return {
		name: 'refui-hmr-inject',
		apply,

		// Rollup-only: record whether we are running a production build
		buildStart(_, inputOptions) {
			// inputOptions is undefined in Vite; OK
			if (inputOptions) {
				// rollup passes `{command: 'build'|'serve'}`
				// @ts-expect-error
				isBuild = (this.meta.watchMode === false); // equals "rollup -c" build
			}
		},

		transform(code, id) {
			if (!filter(id)) return null;          // wrong file type
			if (isBuild) return null;              // production build – skip
			if (code.includes(BEGIN)) return null; // already injected

			return {
				code: `${code}\n${snippet}`,
				map: null
			};
		}
	};
}