运行“npm start”时出现循环错误？答案

【问题标题】：Cycle error occurs when running 'npm start'?运行“npm start”时出现循环错误？
【发布时间】：2020-07-02 13:01:37
【问题描述】：

我正在尝试在我的计算机上本地运行节点应用程序。我在命令行上运行 npm start 时收到以下错误：

npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! node-express@1.0.0 start: `node index`
npm ERR! Exit status 1
npm ERR! 
npm ERR! Failed at the node-express@1.0.0 start script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

这是我的package.json：

{
  "name": "node-express",
  "version": "1.0.0",
  "description": "Node Express Examples",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "start": "node index"
  },
  "author": "Shilpa Kancharla",
  "license": "ISC",
  "dependencies": {
    "body-parser": "^1.19.0",
    "morgan": "^1.10.0"
  }
}

这是我的index.js：

const express = require('express');
const http = require('http');
const hostname = 'localhost';
const port = 3000;

const app = express();

const morgan = require('morgan');
app.use(morgan('dev'));

app.use(express.static(__dirname + '/public'));

const bodyParser = require('body-parser');
app.use(bodyParser.json());

const dishRouter = require('./routes/dishRouter');
const promoRouter = require('./require/promoRouter');
const leaderRouter = require('./require/leaderRouter');
app.use('/dishes', dishRouter);
app.use('/promotions', promoRouter);
app.use('/leaders', leaderRouter);
app.use((req, res, next) => {
    console.log(req.headers);
    res.statusCode = 200;
    res.setHeader('Content-Type', 'text/html');
    res.end('<html><body><h1>This is an Express Server </h1></body></html>');
});

const server = http.createServer(app);

server.listen(port, hostname, () => {
    console.log(`Server running at http://${hostname}:${port}/`);
});

我尝试安装和卸载节点模块，将start 的名称更改为node index.js 而不是node index，但没有这样的运气。

【问题讨论】：

你缺少express和http包，尝试运行npm install express && npm install http，然后npm start

标签： javascript node.js npm npm-scripts npm-start

【解决方案1】：

使用这个 package.json

{
  "name": "node-express",
  "version": "1.0.0",
  "description": "Node Express Examples",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "start": "nodemon index.js"
  },
  "author": "Shilpa Kancharla",
  "license": "ISC",
  "dependencies": {
    "body-parser": "^1.19.0",
    "express": "^4.17.1",
    "http": "0.0.0",
    "morgan": "^1.10.0"
  },
  "devDependencies": {
    "nodemon": "^2.0.2"
  }
}

现在通过运行以下命令来运行和更新节点模块

npm i or npm install

您现在可以通过运行以下命令开始

npm start

【讨论】：