reusable functions

src/Collapse.jsx

@@ -60,40 +60,44 @@ class Collapse extends Component {
     this.setActiveKey(activeKey);
   }
 
-  getItems() {
+  getNewChild(child, index) {
+    if (!child) return null;
+
     const activeKey = this.state.activeKey;
-    const { prefixCls, accordion, destroyInactivePanel, expandIcon, children } = this.props;
-    const newChildren = [];
+    const { prefixCls, accordion, destroyInactivePanel, expandIcon } = this.props;
+    // If there is no key provide, use the panel order as default key
+    const key = child.key || String(index);
+    const { header, headerClass, disabled } = child.props;
+    let isActive = false;
+    if (accordion) {
+      isActive = activeKey[0] === key;
+    } else {
+      isActive = activeKey.indexOf(key) > -1;
+    }
+
+    const props = {
+      key,
+      header,
+      headerClass,
+      isActive,
+      prefixCls,
+      destroyInactivePanel,
+      openAnimation: this.state.openAnimation,
+      accordion,
+      children: child.props.children,
+      onItemClick: disabled ? null : this.onClickItem.bind(this, key),
+      expandIcon,
+    };
+
+    return React.cloneElement(child, props);
+  }
+
+  getItems() {
+    const { children } = this.props;
     const childList = isFragment(children) ? children.props.children : children;
 
-    Children.forEach(childList, (child, index) => {
-      if (!child) return;
-      // If there is no key provide, use the panel order as default key
-      const key = child.key || String(index);
-      const { header, headerClass, disabled } = child.props;
-      let isActive = false;
-      if (accordion) {
-        isActive = activeKey[0] === key;
-      } else {
-        isActive = activeKey.indexOf(key) > -1;
-      }
+    const newChildren = Children.map(childList, this.getNewChild.bind(this));
 
-      const props = {
-        key,
-        header,
-        headerClass,
-        isActive,
-        prefixCls,
-        destroyInactivePanel,
-        openAnimation: this.state.openAnimation,
-        accordion,
-        children: child.props.children,
-        onItemClick: disabled ? null : () => this.onClickItem(key),
-        expandIcon,
-      };
-
-      newChildren.push(React.cloneElement(child, props));
-    });
     //  ref: https://github.com/ant-design/ant-design/issues/13884
     if (isFragment(children)) {
       return (