错误：即使在 package.json 中列出，也找不到模块“ejs”

Question

My application is not loading the 'EJS' module when I try and invoke routing in my app.js file and I'd like to know why.

My question is very similar in scope to this one , but it has some additional wrinkles to it that were not addressed in the answers there so I thought I'd turn this into a new question entirely.

If I start a very basic app.js file like this that calls ejs it works as expected and raises no errors.

APP.JS:

var express = require('express');
var app = express();

app.set('view engine', 'ejs');

app.get('/', function(req, res){
    res.send("Hello World");
    }).listen(3000, function(){
    console.log("The port is now listening at 3000");
  });

However, once I modify app.js to use routes to render a view I get the error message in the title.

The following script provides the error:

APP.JS:

var express = require('express');
var app = express();
var root = require('./routes/index');

app.set('view engine', 'ejs');
app.set('views', __dirname + '/views');
app.use(express.static(__dirname + '/public'));

app.use(root);

app.listen(3000, function(){
console.log("The port is now listening at 3000");
});

module.exports = app;

My index.js file that I use to establish the route looks like this:

INDEX.JS:

var express = require('express');
var router = express.Router();

/* GET home page. */
router.get('/', function(req, res) {
res.render('index', {
  pageTitle: 'The Formula Generator',
  pageDescription: 'Easily manage and store your supplement formulas',
  pageID: 'home' });
});

module.exports = router;

EJS is correctly loaded in my package.json like so:

PACKAGE.JSON:

"dependencies": {
"body-parser": "~1.15.2",
"cookie-parser": "~1.4.3",
"debug": "~2.2.0",
"ejs": "^2.5.5",
"express": "~4.14.0",
"mongodb": "^2.2.16",
"monk": "^3.1.3",
"morgan": "~1.7.0",
"serve-favicon": "~2.3.0"
 },

It's also installed in my node_modules folder as well.

My file structure currently looks like this:

Answer 1

app.js

var express = require('express');
var app = express();
var root = require('./routes/index');

app.set('view engine', 'ejs');
app.set('views', __dirname + '/views');
app.use(express.static(__dirname + '/public'));

root(app); // pass app to index

app.listen(3000, function(){
console.log("The port is now listening at 3000");
});

module.exports = app;

index.js

var controller = function(app){
    app.get('/', function(req, res) {
    res.render('index', {
      pageTitle: 'The Formula Generator',
      pageDescription: 'Easily manage and store your supplement formulas',
      pageID: 'home' });
    });
};
module.exports = controller;

package.json

{
  "name": "test",
  "version": "0.0.1",
  "private": true,
  "scripts": {
    "start": "node app.js"
  },
  "dependencies": {
    "express": "3.2.6",
    "ejs": "*"
  }
}

Answer 2

在项目的根目录上安装 express 。

npm install express --save