运行中修改代码，热更新失败。
## 运行中修改代码，热更新失败（报warning）。
`npm init egg --type=simple` 初始化的项目
`npm run dev`之后，修改了hi egg！字符串为 ”hi egg！！！“
terminal报warnning。

## 部分截图，错误日志，和最小实现

### 最小实现仓库 
https://github.com/jiashuai1002/eggServer

### 错误日志
Dog  ~/Documents/Node_WorkSpace/Egg/server  npm run dev

> server@1.0.0 dev /Users/JiaShuai1002/Documents/Node_WorkSpace/Egg/server
> egg-bin dev

[egg-ts-helper] create typings/app/controller/index.d.ts (5ms)
[egg-ts-helper] create typings/config/index.d.ts (14ms)
[egg-ts-helper] create typings/config/plugin.d.ts (7ms)
[egg-ts-helper] create typings/app/index.d.ts (1ms)
2020-09-09 11:14:01,155 INFO 12087 [master] node version v12.18.3
2020-09-09 11:14:01,155 INFO 12087 [master] egg version 2.28.0
2020-09-09 11:14:01,877 INFO 12087 [master] agent_worker#1:12089 started (719ms)
2020-09-09 11:14:02,814 INFO 12087 [master] egg started on http://127.0.0.1:7001 (1659ms)
2020-09-09 11:14:13,383 WARN 12089 [agent:development] reload worker because /Users/JiaShuai1002/Documents/Node_WorkSpace/Egg/server/app/controller/home.js change
[2020-09-09 11:14:14.529] [cfork:master:12087] worker:12090 disconnect (exitedAfterDisconnect: true, state: disconnected, isDead: false, worker.disableRefork: false)
[2020-09-09 11:14:14.529] [cfork:master:12087] don't fork new work (refork: false)
2020-09-09 11:14:14,530 INFO 12087 [master] app_worker#1:12090 disconnect, suicide: true, state: disconnected, current workers: ["2"]
[2020-09-09 11:14:14.530] [cfork:master:12087] worker:12090 exit (code: 0, exitedAfterDisconnect: true, state: dead, isDead: true, isExpected: true, worker.disableRefork: false)



### 错误截图

![image](https://user-images.githubusercontent.com/34434315/92556832-7a11de00-f29d-11ea-9f4b-b6e4544d623c.png)




## Context
- **Node Version**:v12.18.3
- **Egg Version**:"^2.15.1"


> 页面热更新是什么意思？这是一个 http 的 API 服务，跟页面有啥关系？下一次请求就应该是新的返回了。

