Add test for const field binding

src/compiler/compile/nodes/Binding.ts

@@ -73,7 +73,7 @@ export default class Binding extends Node {
 
 			variable[this.expression.node.type === 'MemberExpression' ? 'mutated' : 'reassigned'] = true;
 
-			if (!variable.writable) component.error(this.expression.node, {
+			if (info.expression.type === 'Identifier' && !variable.writable) component.error(this.expression.node, {
 				code: 'invalid-binding',
 				message: 'Cannot bind to a variable which is not writable',
 			});

test/validator/samples/binding-const-field/errors.json

@@ -0,0 +1 @@
+[]

test/validator/samples/binding-const-field/input.svelte

@@ -0,0 +1,7 @@
+<script>
+	const dummy = {
+		foo: 'bar'
+	};
+</script>
+
+<input bind:value={dummy.foo}>

test/validator/samples/binding-const/input.svelte

@@ -2,4 +2,4 @@
 	const dummy = 'foo';
 </script>
 
-<input bind:value={dummy}>
+<input bind:value={dummy}>