From 51f2a3b2317738b0146c3276d19dff2000bdddad Mon Sep 17 00:00:00 2001
From: Conduitry <git@chor.date>
Date: Tue, 23 Apr 2019 11:32:37 -0400
Subject: [PATCH 1/2] handle unknown nodes in extract_identifiers (#2510)
 (#2514)

---
 src/compile/utils/scope.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/compile/utils/scope.ts b/src/compile/utils/scope.ts
index d4427c44ff38..20cca46cba3e 100644
--- a/src/compile/utils/scope.ts
+++ b/src/compile/utils/scope.ts
@@ -106,7 +106,7 @@ export function extract_names(param: Node) {
 
 export function extract_identifiers(param: Node) {
 	const nodes: Node[] = [];
-	extractors[param.type](nodes, param);
+	extractors[param.type] && extractors[param.type](nodes, param);
 	return nodes;
 }
 

From 356a1eb8d935cbf8e11bf6f6dc7086af6644b531 Mon Sep 17 00:00:00 2001
From: Conduitry <git@chor.date>
Date: Tue, 23 Apr 2019 11:39:21 -0400
Subject: [PATCH 2/2] add test

---
 test/runtime/samples/reactive-value-mutate/_config.js  | 3 +++
 test/runtime/samples/reactive-value-mutate/main.svelte | 7 +++++++
 2 files changed, 10 insertions(+)
 create mode 100644 test/runtime/samples/reactive-value-mutate/_config.js
 create mode 100644 test/runtime/samples/reactive-value-mutate/main.svelte

diff --git a/test/runtime/samples/reactive-value-mutate/_config.js b/test/runtime/samples/reactive-value-mutate/_config.js
new file mode 100644
index 000000000000..e40881683408
--- /dev/null
+++ b/test/runtime/samples/reactive-value-mutate/_config.js
@@ -0,0 +1,3 @@
+export default {
+	html: `{"bar":42}`
+};
diff --git a/test/runtime/samples/reactive-value-mutate/main.svelte b/test/runtime/samples/reactive-value-mutate/main.svelte
new file mode 100644
index 000000000000..59fc5b7eb5e1
--- /dev/null
+++ b/test/runtime/samples/reactive-value-mutate/main.svelte
@@ -0,0 +1,7 @@
+<script>
+	let foo = {};
+	let bar = 42;
+	$: foo.bar = bar;
+</script>
+
+{JSON.stringify(foo)}