add test for hydration of nested element with expression sibling

test/hydration/samples/expression-sibling/_after.html

@@ -0,0 +1 @@
+<p>1 2 <span>3</span></p>

test/hydration/samples/expression-sibling/_before.html

@@ -0,0 +1 @@
+<p>1 2 <span>3</span></p>

test/hydration/samples/expression-sibling/_config.js

@@ -0,0 +1,19 @@
+export default {
+	snapshot(target) {
+		const p = target.querySelector("p");
+
+		return {
+			p,
+			text: p.childNodes[0],
+			span: p.querySelector("span"),
+		};
+	},
+
+	test(assert, target, snapshot) {
+		const p = target.querySelector("p");
+
+		assert.equal(p, snapshot.p);
+		assert.equal(p.childNodes[0], snapshot.text);
+		assert.equal(p.querySelector("span"), snapshot.span);
+	},
+};

test/hydration/samples/expression-sibling/main.svelte

@@ -0,0 +1 @@
+<p>{1} 2 <span>3</span></p>