Javascript &引用；应用程序错误“；使用Heroku部署节点时

经过几周的尝试，我终于在本地制作了一个运行中的客户端-服务器简易应用程序，并且。。。我试着给Heroku一次机会，所以我的上一个服务器非常混乱和令人沮丧。它似乎在工作，但。。。在“确定”部署后，web显示“应用程序中发生错误，无法为您的页面提供服务。如果您是应用程序所有者，请查看日志以了解详细信息。”

我发现允许在process.env.PORT中运行，不仅修复了8080端口，而且还是同样的错误，尽管仍然在本地工作。有什么建议吗

部署的日志

-----> Node.js app detected
-----> Creating runtime environment

       NPM_CONFIG_LOGLEVEL=error
       NODE_VERBOSE=false
       NODE_ENV=production
       NODE_MODULES_CACHE=true
-----> Installing binaries
       engines.node (package.json):  unspecified
       engines.npm (package.json):   unspecified (use default)

       Resolving node version 8.x...
       Downloading and installing node 8.11.1...
       Using default npm version: 5.6.0
-----> Restoring cache
       Loading 2 from cacheDirectories (default):
       - node_modules
       - bower_components (not cached - skipping)
-----> Building dependencies
       Installing node modules (package.json + package-lock)
       up to date in 3.888s
-----> Caching build
       Clearing previous node cache
       Saving 2 cacheDirectories (default):
       - node_modules
       - bower_components (nothing to cache)
-----> Pruning devDependencies
       Skipping because npm 5.6.0 sometimes fails when running 'npm prune' due to a known issue
       https://github.com/npm/npm/issues/19356

       You can silence this warning by updating to at least npm 5.7.1 in your package.json
       https://devcenter.heroku.com/articles/nodejs-support#specifying-an-npm-version
-----> Build succeeded!
-----> Discovering process types
       Procfile declares types     -> (none)
       Default types for buildpack -> web
-----> Compressing...
       Done: 19.4M
-----> Launching...
       Released v5
       https://myweb.herokuapp.com/ deployed to Heroku

---

在JSON文件中，您是否记得包含“start”值，这是您希望服务器在启动时执行的命令。对于节点，JSON的开头应该如下所示：

{
  "name": "deploying",
  "version": "1.0.0",
  "description": "",
  "main": "app.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "start": "node app.js"

希望这有帮助：）

请。接受你已经做过的回答就足够了。