Heroku (MERN) 中没有指定默认引擎，也没有提供扩展

Question

所以我得到了我的 MERN 应用程序，我想在 Heroku 中上传它。

一切正常，直到我访问我的 Heroku 应用 URL 并且在日志中，我收到此错误：No default engine was specified and no extension was provided

我会使用 app.set('view engine', 'ejs'); 但我正在使用 React - MERN。

节点：

const express = require('express');
const logger = require('morgan');
const passport = require('./passport/');
const PORT = process.env.PORT || 8080;
const app = express();
const mongoose = require('mongoose');
mongoose.connect('mongodb', {useNewUrlParser: true})
const indexRouter = require('./routes/index');
const usersRouter = require('./routes/users');
const session = require('express-session');
const MongoStore = require('connect-mongo')(session);
app.use(passport.initialize());
app.use(passport.session());
app.use(session({
    resave: false,
    saveUninitialized: false,
    secret: 'secret here',
    store: new MongoStore({ mongooseConnection: mongoose.connection })
}))

app.use(logger('dev'));
app.use(express.json());
app.use(express.urlencoded({ extended: false }));

app.use('/', indexRouter);
app.use('/authentication', usersRouter);

if (process.env.NODE_ENV === 'production') {
    app.use(express.static('client/build'))

    app.get("*", (req, res) => {
        res.sendFile(path.resolve(__dirname, "../client", "build", "index.html"))
    })
}


app.listen(PORT);

module.exports = app

package.json:

{
  "name": "name",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "start": "nodemon app.js",
    "heroku-postbuild": "NPM_CONFIG_PRODUCTION=false npm install --prefix client && npm run build --prefix client"
  }
  }
}

有谁知道如何解决这个问题？

-非常感谢

Answer 1

也许可以尝试 res.sendFile(path.resolve(__dirname, "client", "build", "index.html")) 因为使用 __dirname 会转到主目录

Answer 2

我认为你需要像这样在 package.json 上写它：

{
  "name": "name",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "engines": {
    "node": "12.13.0",
    "npm": "6.14.4"
  },
  "scripts": {
    "start": "nodemon app.js",
    "heroku-postbuild": "NPM_CONFIG_PRODUCTION=false npm install --prefix client && npm run build --prefix client"
  }
}

Replace node and npm with what you need and the same version you have in local.

Heroku (MERN) 中没有指定默认引擎，也没有提供扩展

No default engine was specified and no extension was provided in Heroku (MERN)

deployment

heroku

internal-server-error

reactjs

mern