Fixing #2668, add test case "each-block-keyed-containing-self-in-if"

test/runtime/samples/each-block-keyed-containing-self-in-if/Nested.svelte

@@ -0,0 +1,5 @@
+<script>
+	export let item;
+</script>
+
+<span>{item.id}</span>

test/runtime/samples/each-block-keyed-containing-self-in-if/_config.js

@@ -0,0 +1,48 @@
+export default {
+	props: {
+		list: [
+			{ id: 1 },
+			{ id: 2 },
+			{ id: 3, children: [{ id: 30 }, { id: 31 }, { id: 32 }] },
+		],
+		activeId: null,
+	},
+
+	html: `
+		<ul>
+			<li><span>1</span></li>
+			<li><span>2</span></li>
+			<li><span>3</span></li>
+		</ul>
+	`,
+
+	test({ assert, component, target }) {
+		component.activeId = 3;
+
+		assert.htmlEqual(target.innerHTML, `
+			<ul>
+				<li><span>1</span></li>
+				<li><span>2</span></li>
+				<li>
+					<span>3</span>
+					<ul>
+						<li><span>30</span></li>
+						<li><span>31</span></li>
+						<li><span>32</span></li>
+					</ul>
+				</li>
+			</ul>
+		`);
+
+
+		component.activeId = null;
+
+		assert.htmlEqual(target.innerHTML, `
+			<ul>
+				<li><span>1</span></li>
+				<li><span>2</span></li>
+				<li><span>3</span></li>
+			</ul>
+		`);
+	}
+};

test/runtime/samples/each-block-keyed-containing-self-in-if/main.svelte

@@ -0,0 +1,17 @@
+<script>
+	import Nested from './Nested.svelte';
+
+	export let list;
+	export let activeId;
+</script>
+
+<ul>
+	{#each list as item (item.id)}
+		<li>
+			<Nested {item} />
+			{#if item.id === activeId && item.children}
+				<svelte:self list={item.children} />
+			{/if}
+		</li>
+	{/each}
+</ul>