svelte/test/runtime/samples/events-custom/_config.js

export default {
	test(assert, component) {
		let count = 0;

		const expected = { x: 1 };

		component.$on('foo', data => {
			assert.equal(data, expected);
			count += 1;
		});

		component.fire('foo', expected);
		assert.equal(count, 1);
	}
};