chore: update codegen

Author: edison1105

packages/compiler-ssr/__tests__/ssrTransitionGroup.spec.ts

@@ -11,7 +11,7 @@ describe('transition-group', () => {
       "const { ssrRenderList: _ssrRenderList } = require("vue/server-renderer")
 
       return function ssrRender(_ctx, _push, _parent, _attrs) {
-        const _tag = _attrs && _attrs.tag
+        const _tag = (_attrs && typeof _attrs.tag === 'string') ? _attrs.tag : ''
         if (_tag) {
           _push(\`<\${_tag}>\`)
         }
@@ -121,7 +121,7 @@ describe('transition-group', () => {
       "const { ssrRenderList: _ssrRenderList } = require("vue/server-renderer")
 
       return function ssrRender(_ctx, _push, _parent, _attrs) {
-        const _tag = _attrs && _attrs.tag
+        const _tag = (_attrs && typeof _attrs.tag === 'string') ? _attrs.tag : ''
         if (_tag) {
           _push(\`<\${_tag}>\`)
         }

packages/compiler-ssr/src/transforms/ssrTransformTransitionGroup.ts

@@ -126,7 +126,10 @@ export function ssrProcessTransitionGroup(
     )
     if (hasFallthroughAttrs) {
       context.pushStatement(
-        createSimpleExpression('const _tag = _attrs && _attrs.tag'),
+        // 这里还得考虑 tag 不是 string 的情况
+        createSimpleExpression(
+          `const _tag = (_attrs && typeof _attrs.tag === 'string') ? _attrs.tag : ''`,
+        ),
       )
       context.pushStatement(
         createIfStatement(