From 58b7b5b325a8668b3ab80733767ceb78ef75d0d8 Mon Sep 17 00:00:00 2001
From: Tan Li Hau <lhtan93@gmail.com>
Date: Sat, 16 Nov 2019 10:35:37 +0800
Subject: [PATCH] fix dynamic event handler expression

---
 src/compiler/compile/nodes/EventHandler.ts    |  2 ++
 .../_config.js                                | 20 +++++++++++++++++++
 .../main.svelte                               | 12 +++++++++++
 3 files changed, 34 insertions(+)
 create mode 100644 test/runtime/samples/event-handler-dynamic-expression/_config.js
 create mode 100644 test/runtime/samples/event-handler-dynamic-expression/main.svelte

diff --git a/src/compiler/compile/nodes/EventHandler.ts b/src/compiler/compile/nodes/EventHandler.ts
index 19da3d9dd7..bee10be659 100644
--- a/src/compiler/compile/nodes/EventHandler.ts
+++ b/src/compiler/compile/nodes/EventHandler.ts
@@ -44,6 +44,8 @@ export default class EventHandler extends Node {
 
 					this.reassigned = component.var_lookup.get(info.expression.name).reassigned;
 				}
+			} else if (this.expression.dynamic_dependencies().length > 0) {
+				this.reassigned = true;
 			}
 		} else {
 			this.handler_name = component.get_unique_name(`${sanitize(this.name)}_handler`);
diff --git a/test/runtime/samples/event-handler-dynamic-expression/_config.js b/test/runtime/samples/event-handler-dynamic-expression/_config.js
new file mode 100644
index 0000000000..c4d259a542
--- /dev/null
+++ b/test/runtime/samples/event-handler-dynamic-expression/_config.js
@@ -0,0 +1,20 @@
+export default {
+	html: `<button>bar</button>`,
+
+	async test({ assert, component, target, window }) {
+		const [button] = target.querySelectorAll(
+			'button'
+		);
+
+		const event = new window.MouseEvent('click');
+
+		await button.dispatchEvent(event);
+		assert.htmlEqual(target.innerHTML, `<button>foo</button>`);
+		
+		await button.dispatchEvent(event);
+		assert.htmlEqual(target.innerHTML, `<button>bar</button>`);
+		
+		await button.dispatchEvent(event);
+		assert.htmlEqual(target.innerHTML, `<button>foo</button>`);
+	},
+};
diff --git a/test/runtime/samples/event-handler-dynamic-expression/main.svelte b/test/runtime/samples/event-handler-dynamic-expression/main.svelte
new file mode 100644
index 0000000000..f53aa7aadd
--- /dev/null
+++ b/test/runtime/samples/event-handler-dynamic-expression/main.svelte
@@ -0,0 +1,12 @@
+<script>
+	let name = 'bar';
+	function foo() {
+		name = 'foo';
+	}
+	function bar() {
+		name = 'bar';
+	}
+	
+</script>
+
+<button on:click={name === 'bar' ? foo : bar}>{name}</button>
\ No newline at end of file