From 946a730880f2df54a7ce20c097fe0448dc80f622 Mon Sep 17 00:00:00 2001
From: daiwei <daiwei521@126.com>
Date: Mon, 21 Aug 2023 16:05:42 +0800
Subject: [PATCH 1/3] fix(custom-element): properly set attr

---
 packages/runtime-dom/src/apiCustomElement.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/runtime-dom/src/apiCustomElement.ts b/packages/runtime-dom/src/apiCustomElement.ts
index 5662b0b535b..3af3f795b8e 100644
--- a/packages/runtime-dom/src/apiCustomElement.ts
+++ b/packages/runtime-dom/src/apiCustomElement.ts
@@ -313,7 +313,7 @@ export class VueElement extends BaseClass {
   }
 
   protected _setAttr(key: string) {
-    let value = this.getAttribute(key)
+    let value = this.hasAttribute(key) ? this.getAttribute(key) : undefined
     const camelKey = camelize(key)
     if (this._numberProps && this._numberProps[camelKey]) {
       value = toNumber(value)

From e1287fc568aa8bd83ca835da6ec8183de8b19e0b Mon Sep 17 00:00:00 2001
From: daiwei <daiwei521@126.com>
Date: Tue, 22 Aug 2023 09:58:12 +0800
Subject: [PATCH 2/3] test: update test case

---
 packages/runtime-dom/__tests__/customElement.spec.ts | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/packages/runtime-dom/__tests__/customElement.spec.ts b/packages/runtime-dom/__tests__/customElement.spec.ts
index 6ccf02c4fa6..445ba1ebe8f 100644
--- a/packages/runtime-dom/__tests__/customElement.spec.ts
+++ b/packages/runtime-dom/__tests__/customElement.spec.ts
@@ -134,10 +134,11 @@ describe('defineCustomElement', () => {
       expect(e.shadowRoot!.innerHTML).toBe('<div>three</div><div>two</div>')
       expect(e.getAttribute('foo')).toBe('three')
 
-      e.foo = null
+      e.foo = undefined
       await nextTick()
       expect(e.shadowRoot!.innerHTML).toBe('<div></div><div>two</div>')
       expect(e.hasAttribute('foo')).toBe(false)
+      expect(e.foo).toBe(undefined)
 
       e.bazQux = 'four'
       await nextTick()

From 0180ac5f9963d72e9d1181c0a8a1ef0b813a17ca Mon Sep 17 00:00:00 2001
From: daiwei <daiwei521@126.com>
Date: Tue, 22 Aug 2023 10:36:02 +0800
Subject: [PATCH 3/3] test: update test case

---
 packages/runtime-dom/__tests__/customElement.spec.ts | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/packages/runtime-dom/__tests__/customElement.spec.ts b/packages/runtime-dom/__tests__/customElement.spec.ts
index 445ba1ebe8f..a3f3ceac229 100644
--- a/packages/runtime-dom/__tests__/customElement.spec.ts
+++ b/packages/runtime-dom/__tests__/customElement.spec.ts
@@ -134,6 +134,11 @@ describe('defineCustomElement', () => {
       expect(e.shadowRoot!.innerHTML).toBe('<div>three</div><div>two</div>')
       expect(e.getAttribute('foo')).toBe('three')
 
+      e.foo = null
+      await nextTick()
+      expect(e.shadowRoot!.innerHTML).toBe('<div></div><div>two</div>')
+      expect(e.hasAttribute('foo')).toBe(false)
+
       e.foo = undefined
       await nextTick()
       expect(e.shadowRoot!.innerHTML).toBe('<div></div><div>two</div>')