From e79ee34c258d6550ad5600e11ef918294c8f41e6 Mon Sep 17 00:00:00 2001
From: Billy Levin <billy.levin97@gmail.com>
Date: Sun, 17 May 2020 20:40:54 +0100
Subject: [PATCH] react to array mutation in each block with static content

---
 .../compile/render_dom/wrappers/EachBlock.ts        | 13 +++++++++++++
 .../samples/each-block-static-update/_config.js     |  7 +++++++
 .../samples/each-block-static-update/main.svelte    | 13 +++++++++++++
 3 files changed, 33 insertions(+)
 create mode 100644 test/runtime/samples/each-block-static-update/_config.js
 create mode 100644 test/runtime/samples/each-block-static-update/main.svelte

diff --git a/src/compiler/compile/render_dom/wrappers/EachBlock.ts b/src/compiler/compile/render_dom/wrappers/EachBlock.ts
index 1efadfb90c..f963929625 100644
--- a/src/compiler/compile/render_dom/wrappers/EachBlock.ts
+++ b/src/compiler/compile/render_dom/wrappers/EachBlock.ts
@@ -96,6 +96,19 @@ export default class EachBlockWrapper extends Wrapper {
 			bindings: new Map(block.bindings)
 		});
 
+		const reassigned_deps: Set<string> = new Set();
+
+		block.dependencies.forEach(dep => {
+			const info = renderer.context_lookup.get(dep);
+			if (info && info.variable.reassigned) {
+				reassigned_deps.add(dep);
+			}
+		});
+
+		if (reassigned_deps.size) {
+			this.block.add_dependencies(reassigned_deps);
+		}
+
 		// TODO this seems messy
 		this.block.has_animation = this.node.has_animation;
 
diff --git a/test/runtime/samples/each-block-static-update/_config.js b/test/runtime/samples/each-block-static-update/_config.js
new file mode 100644
index 0000000000..dc1047e99b
--- /dev/null
+++ b/test/runtime/samples/each-block-static-update/_config.js
@@ -0,0 +1,7 @@
+export default {
+	html: ``,
+
+	test({ assert, target }) {
+		assert.htmlEqual(target.innerHTML, `staticstatic`);
+	}
+};
diff --git a/test/runtime/samples/each-block-static-update/main.svelte b/test/runtime/samples/each-block-static-update/main.svelte
new file mode 100644
index 0000000000..6cbd1e7548
--- /dev/null
+++ b/test/runtime/samples/each-block-static-update/main.svelte
@@ -0,0 +1,13 @@
+<script>
+	import { onMount } from 'svelte';
+	let arr = [1];
+	
+	onMount(() => {
+		arr.push(arr.length + 1);
+		arr = arr;
+	});
+</script>
+
+{#each arr as num}
+	static
+{/each}
\ No newline at end of file