Node.js 无法将firebase数据库中的数据检索到heroku应用程序中

我已经创建了一个angular应用程序：。任务保存在firebase数据库中，可以在任务标题下看到

该应用程序在本地主机上运行良好，但在heroku上部署后，它没有显示任务。看看这个

我做错了什么

这是屏幕截图中显示的完整错误：

ERROR TypeError: Ia.Observable is not a constructor
    at Aa (main.c0eb70b5514f5eed42fe.js:1)
    at main.c0eb70b5514f5eed42fe.js:1
    at Fa (main.c0eb70b5514f5eed42fe.js:1)
    at Object.snapshotChanges (main.c0eb70b5514f5eed42fe.js:1)
    at t.ngOnInit (main.c0eb70b5514f5eed42fe.js:1)
    at Ne (main.c0eb70b5514f5eed42fe.js:1)
    at Oe (main.c0eb70b5514f5eed42fe.js:1)
    at xe (main.c0eb70b5514f5eed42fe.js:1)
    at Hn (main.c0eb70b5514f5eed42fe.js:1)
    at ur (main.c0eb70b5514f5eed42fe.js:1)

package.json

{
  "name": "todolistapp",
  "version": "0.0.0",
  "scripts": {
    "ng": "ng",
    "start": "node server.js",
    "build": "ng build",
    "test": "ng test",
    "lint": "ng lint",
    "e2e": "ng e2e",
    "heroku-postbuild": "ng build --prod"
  },
  "private": true,
  "dependencies": {
    "@angular/animations": "~10.1.1",
    "@angular/common": "~10.1.1",
    "@angular/compiler": "~10.1.1",
    "@angular/core": "~10.1.1",
    "@angular/forms": "~10.1.1",
    "@angular/platform-browser": "~10.1.1",
    "@angular/platform-browser-dynamic": "~10.1.1",
    "@angular/router": "~10.1.1",
    "angularfire2": "^5.0.0-rc.3",
    "express": "^4.17.1",
    "firebase": "^4.6.1",
    "path": "^0.12.7",
    "rxjs": "~6.6.0",
    "rxjs-compat": "^6.6.3",
    "tslib": "^2.0.0",
    "typescript": "~4.0.2",
    "zone.js": "~0.10.2"
  },
  "devDependencies": {
    "@angular-devkit/build-angular": "~0.1001.1",
    "@angular/cli": "~10.1.1",
    "@angular/compiler-cli": "~10.1.1",
    "@types/node": "^12.11.1",
    "@types/jasmine": "~3.5.0",
    "@types/jasminewd2": "~2.0.3",
    "codelyzer": "^6.0.0",
    "jasmine-core": "~3.6.0",
    "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": "~4.0.0",
    "karma-jasmine-html-reporter": "^1.5.0",
    "protractor": "~7.0.0",
    "ts-node": "~8.3.0",
    "tslint": "~6.1.0",
    "typescript": "~4.0.2"
  },
  "engines": {
    "node": "12.16.2",
    "npm": "6.14.4"
  }
}

环境产品

export const environment = {
  production: true,
  firebase: {
    apiKey: "SOME_CREDENTIALS",
    authDomain: "SOME_CREDENTIALS",
    databaseURL: "SOME_CREDENTIALS",
    projectId: "SOME_CREDENTIALS",
    storageBucket: "SOME_CREDENTIALS",
    messagingSenderId: "SOME_CREDENTIALS",
    appId: "SOME_CREDENTIALS",
    measurementId: "SOME_CREDENTIALS"
  }
};

server.js

//Install express server
const express = require('express');
const path = require('path');

const app = express();

// Serve only the static files form the dist directory
app.use(express.static(__dirname + '/dist/todolistapp'));

app.get('/*', function(req,res) {

res.sendFile(path.join(__dirname+'/dist/todolistapp/index.html'));
});

// Start the app by listening on the default Heroku port
app.listen(process.env.PORT || 8080);

---

屏幕截图中显示了一条错误消息，但不幸的是，您没有包括所有信息。请从浏览器中复制完整的错误消息和堆栈跟踪，并将其添加到您的问题中（作为文本，请不要截图）。@FrankvanPuffelen Ya刚刚在问题中添加了完整的错误。请检查它。这是一个来自缩小代码的堆栈跟踪，几乎不可能映射到您共享的任何代码。我想知道缩小是否不是你的问题的原因，因此你可能想看看你是否可以用你的应用程序的缩小/发布版本在本地复制它（从而排除Heroku作为可能的原因）。