fix: card empty slot render

Author: tangjinzhou

components/_util/props-util/index.js

@@ -370,6 +370,15 @@ export function filterEmpty(children = []) {
   return res.filter(c => !isEmptyElement(c));
 }
 
+export function filterEmptyWithUndefined(children) {
+  if (children) {
+    const coms = filterEmpty(children);
+    return coms.length ? coms : undefined;
+  } else {
+    return children;
+  }
+}
+
 export function mergeProps() {
   const args = [].slice.call(arguments, 0);
   const props = {};

components/card/Card.tsx

@@ -4,7 +4,7 @@ import Tabs from '../tabs';
 import Row from '../row';
 import Col from '../col';
 import PropTypes from '../_util/vue-types';
-import { flattenChildren, isEmptyElement } from '../_util/props-util';
+import { flattenChildren, isEmptyElement, filterEmptyWithUndefined } from '../_util/props-util';
 import type { SizeType } from '../config-provider';
 import isPlainObject from 'lodash-es/isPlainObject';
 import useConfigInject from '../_util/hooks/useConfigInject';
@@ -88,11 +88,11 @@ const Card = defineComponent({
         hoverable,
         activeTabKey,
         defaultActiveTabKey,
-        tabBarExtraContent = slots.tabBarExtraContent?.(),
-        title = slots.title?.(),
-        extra = slots.extra?.(),
-        actions = slots.actions?.(),
-        cover = slots.cover?.(),
+        tabBarExtraContent = filterEmptyWithUndefined(slots.tabBarExtraContent?.()),
+        title = filterEmptyWithUndefined(slots.title?.()),
+        extra = filterEmptyWithUndefined(slots.extra?.()),
+        actions = filterEmptyWithUndefined(slots.actions?.()),
+        cover = filterEmptyWithUndefined(slots.cover?.()),
       } = props;
       const children = flattenChildren(slots.default?.());
       const pre = prefixCls.value;