docs: update doc

Author: mujue

README.md

@@ -124,12 +124,6 @@ function Demo() {
 }
 ```
 
-#### useSetState
-
-#### 规则陷阱
-
-> eslint-hooks 插件
-
 ### 相关链接
 
 * [React Hooks 深入系列](https://github.com/MuYunyun/blog/blob/master/React/React_Hooks深入系列.md)

src/index.js

@@ -2,18 +2,20 @@ import React from "react"
 import ReactDOM from "react-dom"
 import { HookApp, ClassApp } from './tasks/task1'
 import { Demo } from './tasks/task2'
+import { RuleCase } from "./tasks/task3";
 import useInterval from './useInterval'
 import "./styles.css"
 
 function View() {
   return (
-    <React.Fragment>
+    <>
       {/* <HookApp />
       <hr />
       <ClassApp />
       <hr /> */}
-      <Demo />
-    </React.Fragment>
+      {/* <Demo /> */}
+      <RuleCase />
+    </>
   );
 }
 

src/tasks/task3.js

@@ -0,0 +1,22 @@
+import React from "react"
+
+const { useState, useEffect, useReducer } = React
+
+// function useTimer() {
+//   const [date, setDate] = useState(new Date())
+//   return [date]
+// }
+
+// common case
+function RuleCase() {
+  const [value, forceUpdate] = useReducer((n) => n + 1, 0);
+  const [a, setA] = useState(1)
+  if (Math.floor(Math.random() * 100) > 50) { return <div>one</div> }
+  const [b, setB] = useState(2)
+  useEffect(() => {
+    forceUpdate()
+  }, [])
+  return <div>two</div>
+}
+
+export { RuleCase };