svelte/test/runtime/samples/transition-js-nested-intro/_config.js

export default {
	test ( assert, component, target, window, raf ) {
		component.set({ visible: true });
		const div = target.querySelector( 'div' );
		assert.equal( div.foo, 0 );

		raf.tick( 50 );
		assert.equal( div.foo, 0 );

		raf.tick( 100 );
		assert.equal( div.foo, 0.5 );

		raf.tick( 125 );
		assert.equal( div.foo, 0.75 );

		raf.tick( 150 );
		assert.equal( div.foo, 1 );

		component.destroy();
	}
};