svelte/test/runtime/samples/set-clones-input/_config.js

export default {
	compileOptions: {
		dev: true
	},

	data: {
		a: 42
	},

	test ( assert, component ) {
		const obj = { a: 1 };
		component.set( obj );
		component.set( obj ); // will fail if the object is not cloned
		component.destroy();
	}
};