Question

我正在构建连接到Node / Express后端的Angular应用。即使在我的项目中成功安装了node，nodemon和express之后，尝试使用 npm run start：server

启动我的节点服务器时，我仍然收到以下错误

请注意，使用 ng serve 命令

Angular代码可以正常运行

这是我的package.json

  "name": "mean",
  "version": "0.0.0",
  "scripts": {
    "ng": "ng",
    "start": "ng serve",
    "build": "ng build",
    "test": "ng test",
    "lint": "ng lint",
    "e2e": "ng e2e",
    "start:server": "nodemon server.js"
  },
  "private": true,
  "dependencies": {
    "@angular/animations": "~10.0.3",
    "@angular/cdk": "~10.0.2",
    "@angular/common": "~10.0.3",
    "@angular/compiler": "~10.0.3",
    "@angular/core": "~10.0.3",
    "@angular/forms": "~10.0.3",
    "@angular/material": "^10.0.2",
    "@angular/platform-browser": "~10.0.3",
    "@angular/platform-browser-dynamic": "~10.0.3",
    "@angular/router": "~10.0.3",
    "express": "^4.17.1",
    "rxjs": "~6.6.0",
    "tslib": "^2.0.0",
    "zone.js": "~0.10.3"
  },
  "devDependencies": {
    "@angular-devkit/build-angular": "~0.1000.2",
    "@angular/cli": "~10.0.2",
    "@angular/compiler-cli": "~10.0.3",
    "@angular/language-service": "~10.0.3",
    "@types/jasmine": "~3.3.8",
    "@types/jasminewd2": "~2.0.3",
    "@types/node": "^12.11.1",
    "codelyzer": "^6.0.0",
    "jasmine-core": "~3.5.0",
    "jasmine-spec-reporter": "~5.0.0",
    "karma": "~5.0.0",
    "karma-chrome-launcher": "~3.1.0",
    "karma-coverage-istanbul-reporter": "~3.0.2",
    "karma-jasmine": "~3.3.0",
    "karma-jasmine-html-reporter": "^1.5.0",
    "nodemon": "^2.0.4",
    "protractor": "~7.0.0",
    "ts-node": "~7.0.0",
    "tslint": "~6.1.0",
    "typescript": "~3.9.6"
  }
}

这是我的server.js

const app = require("./backend/app");
const debug = require("debug")("node-angular");
const http = require("http");

const normalizePort = val => {
  var port = parseInt(val, 10);

  if (isNaN(port)) {
    // named pipe
    return val;
  }

  if (port >= 0) {
    // port number
    return port;
  }

  return false;
};

//Check which type of errors occur
const onError = error => {
  if (error.syscall !== "listen") {
    throw error;
  }
  const bind = typeof port === "string" ? "pipe " + port : "port " + port;
  switch (error.code) {
    case "EACCES":
      console.error(bind + " requires elevated privileges");
      process.exit(1);
      break;
    case "EADDRINUSE":
      console.error(bind + " is already in use");
      process.exit(1);
      break;
    default:
      throw error;
  }
};

const onListening = () => {
  const addr = server.address();
  const bind = typeof port === "string" ? "pipe " + port : "port " + port;
  debug("Listening on " + bind);
};

const port = normalizePort(process.env.PORT || "3001");
app.set("port", port);

const server = http.createServer(app);
server.on("error", onError);
server.on("listening", onListening);
server.listen(port);

这是我的app.js


const app = express();

app.use((req,res,next) =>{
  console.log('First middleware');
   next();
});

app.use((req,res,next) =>{
  res.send('Hello from Express!');
});

module.exports = app;

Answer 1

在package.json中，使用

"start:server": "npx nodemon server.js"

它将起作用。

无法使用npm run start：server启动我的节点服务器

1 个答案: