chore: write a unit test for offsetWidth/offsetHeight (WIP)

test/runtime/samples/binding-width-height-initialize/_config.js

@@ -0,0 +1,5 @@
+export default {
+	async test({ assert, target }) {
+		assert.htmlEqual(target.querySelector('.description').innerHTML, 'width:200, height:100');
+	}
+};

test/runtime/samples/binding-width-height-initialize/main.svelte

@@ -0,0 +1,22 @@
+<script>
+	let offsetWidth = 0;
+	let offsetHeight = 0;
+</script>
+
+<div class="wrapper">
+	<div class="inner" bind:offsetHeight bind:offsetWidth>
+		<div class="description">width:{offsetWidth}, height:{offsetHeight}</div>
+	</div>
+</div>
+
+<style>
+	.wrapper {
+		width: 200px;
+		height: 100px;
+	}
+
+	.inner {
+		width: 100%;
+		height: 100%
+	}
+</style>