From 68906806330cd7b30edd7accd595cfa26d64f754 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E4=BA=8C=E8=B4=A7=E6=9C=BA=E5=99=A8=E4=BA=BA?=
 <smith3816@gmail.com>
Date: Fri, 28 Aug 2020 10:54:02 +0800
Subject: [PATCH] feat: toArray support empty (#141)

---
 src/Children/toArray.ts |  9 +++++++--
 tests/toArray.test.js   | 36 ++++++++++++++++++++++++++++++++++++
 2 files changed, 43 insertions(+), 2 deletions(-)

diff --git a/src/Children/toArray.ts b/src/Children/toArray.ts
index 17f96cd9..91ba5a41 100644
--- a/src/Children/toArray.ts
+++ b/src/Children/toArray.ts
@@ -1,20 +1,25 @@
 import React from 'react';
 import { isFragment } from 'react-is';
 
+export interface Option {
+  keepEmpty?: boolean;
+}
+
 export default function toArray(
   children: React.ReactNode,
+  option: Option = {},
 ): React.ReactElement[] {
   let ret: React.ReactElement[] = [];
 
   React.Children.forEach(children, (child: any) => {
-    if (child === undefined || child === null) {
+    if ((child === undefined || child === null) && !option.keepEmpty) {
       return;
     }
 
     if (Array.isArray(child)) {
       ret = ret.concat(toArray(child));
     } else if (isFragment(child) && child.props) {
-      ret = ret.concat(toArray(child.props.children));
+      ret = ret.concat(toArray(child.props.children, option));
     } else {
       ret.push(child);
     }
diff --git a/tests/toArray.test.js b/tests/toArray.test.js
index ca566d6a..37b5b81b 100644
--- a/tests/toArray.test.js
+++ b/tests/toArray.test.js
@@ -51,4 +51,40 @@ describe('toArray', () => {
     expect(children).toHaveLength(5);
     expect(children.map(c => c.key)).toEqual(['1', '2', '3', '4', '5']);
   });
+
+  it('keep empty', () => {
+    const wrapper = mount(
+      <ul>
+        {null}
+        <li key="1">1</li>
+        <>
+          <li key="2">2</li>
+          {null}
+          <li key="3">3</li>
+        </>
+        <React.Fragment>
+          <>
+            <li key="4">4</li>
+            {undefined}
+            <li key="5">5</li>
+          </>
+        </React.Fragment>
+        {undefined}
+      </ul>,
+    );
+
+    const children = toArray(wrapper.props().children, { keepEmpty: true });
+    expect(children).toHaveLength(9);
+    expect(children.map(c => c && c.key)).toEqual([
+      null,
+      '1',
+      '2',
+      null,
+      '3',
+      '4',
+      null,
+      '5',
+      null,
+    ]);
+  });
 });