add test

packages/svelte/tests/runtime-legacy/samples/component-props-added/_config.js

@@ -0,0 +1,15 @@
+import { test } from '../../test';
+
+export default test({
+	get props() {
+		return {};
+	},
+
+	html: '',
+
+	async test({ assert, component, target }) {
+		await component.$set({ message: 'goodbye' });
+
+		assert.htmlEqual(target.innerHTML, '<p>goodbye</p>');
+	}
+});

packages/svelte/tests/runtime-legacy/samples/component-props-added/main.svelte

@@ -0,0 +1,3 @@
+{#if 'message' in $$props}
+	<p>{$$props.message}</p>
+{/if}