svelte/test/runtime/samples/each-block-keyed-random-permute/_config.js

const VALUES = Array.from('abcdefghijklmnopqrstuvwxyz');

function toObjects(array) {
	return array.split('').map(x => ({ id: x }));
}

function permute() {
	const values = VALUES.slice();
	const number = Math.floor(Math.random() * VALUES.length);
	const permuted = [];
	for (let i = 0; i < number; i++) {
		permuted.push(
			...values.splice(Math.floor(Math.random() * (number - i)), 1)
		);
	}

	return permuted.join('');
}

export default {
	data: {
		values: toObjects('abc'),
	},

	html: `(a)(b)(c)`,

	test(assert, component, target) {
		function test(sequence) {
			const previous = target.textContent;
			const expected = sequence.split('').map(x => `(${x})`).join('');
			component.set({ values: toObjects(sequence) });
			assert.htmlEqual(
				target.innerHTML,
				expected,
				`\n${previous} -> ${expected}\n${target.textContent}`
			);
		}

		// first, some fixed tests so that we can debug them
		test('abc');
		test('abcd');
		test('abecd');
		test('fabecd');
		test('fabed');
		test('beadf');
		test('ghbeadf');
		test('gf');
		test('gc');
		test('g');
		test('');
		test('abc');
		test('duqbmineapjhtlofrskcg');
		test('hdnkjougmrvftewsqpailcb');
		test('bidhfacge');
		test('kgjnempcboaflidh');
		test('fekbijachgd');
		test('kdmlgfbicheja');

		// then, we party
		for (let i = 0; i < 100; i += 1) test(permute());
	}
};