svelte/test/runtime/samples/component-binding-deep-b/_config.js

const components = [
	{
		name: 'One',
		source: 'one source'
	},
	{
		name: 'Two',
		source: 'two source'
	}
];

const selectedComponent = components[0];

export default {
	skip: true, // doesn't reflect real-world bug, maybe a JSDOM quirk

	data: {
		components,
		selectedComponent
	},

	html: `
		<select>
			<option value='[object Object]'>One.html</option>
			<option value='[object Object]'>Two.html</option>
		</select>

		<textarea></textarea>

		<pre>ONE SOURCE\nTWO SOURCE</pre>
	`,

	test ( assert, component, target, window ) {
		const event = new window.MouseEvent( 'input' );
		const textarea = target.querySelector( 'textarea' );

		textarea.value = 'one source changed';
		textarea.dispatchEvent( event );

		assert.equal( component.get().compiled, 'ONE SOURCE CHANGED\nTWO SOURCE' );
		assert.htmlEqual( target.innerHTML, `
			<select>
				<option value='[object Object]'>One.html</option>
				<option value='[object Object]'>Two.html</option>
			</select>

			<textarea></textarea>

			<pre>ONE SOURCE CHANGED\nTWO SOURCE</pre>
		` );

		// const select = target.querySelector( 'select' );
		// console.log( `select.options[0].selected`, select.options[0].selected )
		// console.log( `select.options[1].selected`, select.options[1].selected )
		// console.log( `select.value`, select.value )
		// console.log( `select.__value`, select.__value )
		// select.options[1].selected = true;
		// console.log( `select.options[0].selected`, select.options[0].selected )
		// console.log( `select.options[1].selected`, select.options[1].selected )
		// console.log( `select.value`, select.value )
		// console.log( `select.__value`, select.__value )
		// select.dispatchEvent( new window.Event( 'change' ) );
		component.set({ selectedComponent: components[1] });

		assert.equal( textarea.value, 'two source' );

		textarea.value = 'two source changed';
		textarea.dispatchEvent( event );

		assert.equal( component.get().compiled, 'ONE SOURCE CHANGED\nTWO SOURCE CHANGED' );
		assert.htmlEqual( target.innerHTML, `
			<select>
				<option value='[object Object]'>One.html</option>
				<option value='[object Object]'>Two.html</option>
			</select>

			<textarea></textarea>

			<pre>ONE SOURCE CHANGED\nTWO SOURCE CHANGED</pre>
		` );

		component.destroy();
	}
};