From 8d7d0ff7dd7b248ca6d9b6b4cac098430c6e6ffa Mon Sep 17 00:00:00 2001
From: Conduitry <git@chor.date>
Date: Sat, 19 Oct 2019 08:51:59 -0400
Subject: [PATCH] fix `bind:this` binding to a store (#3591)

---
 CHANGELOG.md                                        | 1 +
 src/compiler/compile/Component.ts                   | 2 +-
 test/runtime/samples/binding-this-store/_config.js  | 4 ++++
 test/runtime/samples/binding-this-store/main.svelte | 6 ++++++
 4 files changed, 12 insertions(+), 1 deletion(-)
 create mode 100644 test/runtime/samples/binding-this-store/_config.js
 create mode 100644 test/runtime/samples/binding-this-store/main.svelte

diff --git a/CHANGELOG.md b/CHANGELOG.md
index e357e58acdc8..c2611da704bc 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,7 @@
 * Allow exiting a reactive block early with `break $` ([#2828](https://github.com/sveltejs/svelte/issues/2828))
 * Check attributes have changed before setting them to avoid image flicker ([#3579](https://github.com/sveltejs/svelte/pull/3579))
 * Fix generating malformed code for `{@debug}` tags with no dependencies ([#3588](https://github.com/sveltejs/svelte/issue/3588))
+* Fix `bind:this` binding to a store ([#3591](https://github.com/sveltejs/svelte/issue/3591))
 * Use safer `HTMLElement` check before extending class ([#3608](https://github.com/sveltejs/svelte/issue/3608))
 * Add `location` as a known global ([#3619](https://github.com/sveltejs/svelte/pull/3619))
 * Support `{#await}` with `{:catch}` but no `{:then}` ([#3623](https://github.com/sveltejs/svelte/issues/3623))
diff --git a/src/compiler/compile/Component.ts b/src/compiler/compile/Component.ts
index 20c0d09e2472..8d1384e7a1d7 100644
--- a/src/compiler/compile/Component.ts
+++ b/src/compiler/compile/Component.ts
@@ -764,7 +764,7 @@ export default class Component {
 		}
 
 		if (name[0] === '$' && name[1] !== '$') {
-			return x`${name.slice(1)}.set(${name})`;
+			return x`${name.slice(1)}.set(${value || name})`;
 		}
 
 		if (
diff --git a/test/runtime/samples/binding-this-store/_config.js b/test/runtime/samples/binding-this-store/_config.js
new file mode 100644
index 000000000000..f818c2e31e4b
--- /dev/null
+++ b/test/runtime/samples/binding-this-store/_config.js
@@ -0,0 +1,4 @@
+export default {
+	skip_if_ssr: true,
+	html: `<div>object</div>`
+};
diff --git a/test/runtime/samples/binding-this-store/main.svelte b/test/runtime/samples/binding-this-store/main.svelte
new file mode 100644
index 000000000000..7958dfa2d817
--- /dev/null
+++ b/test/runtime/samples/binding-this-store/main.svelte
@@ -0,0 +1,6 @@
+<script>
+	import { writable } from 'svelte/store';
+	const foo = writable();
+</script>
+
+<div bind:this={$foo}>{typeof $foo}</div>