From 912c8bad38e9564e2f7cfd2afd0c578bd28cda49 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Michal=20Vlas=C3=A1k?= <daeatel@gmail.com>
Date: Wed, 4 Mar 2020 16:34:10 +0100
Subject: [PATCH] Add check for binding non-writable variables

---
 src/compiler/compile/nodes/Binding.ts | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/compiler/compile/nodes/Binding.ts b/src/compiler/compile/nodes/Binding.ts
index 7d6fad0a81..4028ad699b 100644
--- a/src/compiler/compile/nodes/Binding.ts
+++ b/src/compiler/compile/nodes/Binding.ts
@@ -72,6 +72,11 @@ export default class Binding extends Node {
 			});
 
 			variable[this.expression.node.type === 'MemberExpression' ? 'mutated' : 'reassigned'] = true;
+
+			if (!variable.writable) component.error(this.expression.node, {
+				code: 'invalid-binding',
+				message: 'Cannot bind to a variable which is not writable',
+			});
 		}
 
 		const type = parent.get_static_attribute_value('type');