使用 concurrently 並行地運行多個命令（同時跑前端和後端的服務）

我如今有一個項目是這樣的，前端是用 React 寫的，後端是用 Nodejs，目錄結構以下：

1 .
2 ├── README.md
3 ├── backend
4 ├── node_modules
5 ├── package.json
6 ├── public
7 ├── src
8 └── yarn.lock

這個 package.json 的內容以下：

 1 {
 2   "name": "crudtest",
 3   "version": "0.1.0",
 4   "private": true,
 5   "dependencies": {
 6     "classnames": "^2.2.5",
 7     "concurrently": "^3.5.1",
 8     "react": "^16.2.0",
 9     "react-dom": "^16.2.0",
10     "react-redux": "^5.0.7",
11     "react-router-dom": "^4.2.2",
12     "react-scripts": "1.1.1",
13     "redux": "^3.7.2",
14     "redux-thunk": "^2.2.0"
15   },
16   "scripts": {
17     "start": "react-scripts start",
18     "build": "react-scripts build",
19     "test": "react-scripts test --env=jsdom",
20     "eject": "react-scripts eject",
21   },
22   "devDependencies": {
23     "redux-devtools-extension": "^2.13.2"
24   },
25   "proxy": "http://localhost:8080"
26 }

然後端項目是放在 backend 這個目錄中，其目錄結構以下：

1 backend
2 ├── etc
3 ├── node_modules
4 ├── package-lock.json
5 ├── package.json
6 └── server.js

它的 package.json 文件，內容以下：

 1 {
 2   "name": "backend",
 3   "version": "1.0.0",
 4   "description": "",
 5   "main": "server.js",
 6   "scripts": {
 7     "test": "echo \"Error: no test specified\" && exit 1",
 8     "start": "nodemon --exec babel-node -- ./server.js"
 9   },
10   "keywords": [],
11   "author": "",
12   "license": "ISC",
13   "dependencies": {
14     "body-parser": "^1.18.2",
15     "express": "^4.16.2",
16     "mongodb": "^3.0.4"
17   },
18   "devDependencies": {
19     "babel-cli": "^6.26.0",
20     "babel-preset-es2015": "^6.24.1",
21     "nodemon": "^1.17.1"
22   }
23 }

如今前端項目要運行起來簡單，只要運行以下命令便可。

$ npm run start

就會跑 3000 端口。

那麼要運行服務器的程序的話，可能要這樣：

1 $ cd backend
2 $ npm run start

就會跑 8080 端口。

那麼有沒有一種方法同時運行兩個服務呢？

就是用一條命令跑兩個服務。

解決方法以下：

一、在項目根目錄下，運行：

1 $ npm i concurrently --save
2 或
3 $ yarn add concurrently

1. 而後更改 package.json 文件，以下：

 1 {
 2   "name": "crudtest",
 3   "version": "0.1.0",
 4   "private": true,
 5   "dependencies": {
 6     "classnames": "^2.2.5",
 7     "concurrently": "^3.5.1",
 8     "react": "^16.2.0",
 9     "react-dom": "^16.2.0",
10     "react-redux": "^5.0.7",
11     "react-router-dom": "^4.2.2",
12     "react-scripts": "1.1.1",
13     "redux": "^3.7.2",
14     "redux-thunk": "^2.2.0"
15   },
16   "scripts": {
17     "start": "react-scripts start",
18     "build": "react-scripts build",
19     "test": "react-scripts test --env=jsdom",
20     "eject": "react-scripts eject",
21     "server": "npm start --prefix backend",
22     "dev": "concurrently \"npm run server\" \"npm run start\""
23   },
24   "devDependencies": {
25     "redux-devtools-extension": "^2.13.2"
26   },
27   "proxy": "http://localhost:8080"
28 }

主要添加了下面這兩行：

1 "server": "npm start --prefix backend",
2 "dev": "concurrently \"npm run server\" \"npm run start\""

有了 --prefix backend 就不用 cd backend 了，也就是說運行 npm run server 就會跑後端的服務，至關於：

1 $ cd backend
2 $ npm run start

最後運行 npm run dev 至關於同時運行下面兩條命令：

1 $ npm run server
2 $ npm run start

界面以下：

原文訪問