I am new to Node.js, try to learn express to build my first web application. I got stuck on my very first sample code and need some help to get it running. Before I post this question, I did search on stack overflow, found some similar questions but still could not fix it.

Error: Cannot find module 'express'

I am using mac os 10.8.2. I have Node.js installed using nvm.

node.js: 0.8.20 path to node: /Users/feelexit/nvm/v0.8.20/bin/node path to express: /Users/feelexit/nvm/node_modules/express

here's my sample code: this file locates at:

/Users/feelexit/WebstormProjects/learnnode/node_modules/index.js

var express = require('express'); var app = express(); app.get('/', function(req, res){ res.send('welcome to express'); }); app.listen(3000);

when I try to run this command node index.js I get following error message, please help me to fix it.

Thank you.

Error: Cannot find module 'express' at Function.Module._resolveFilename (module.js:338:15) at Function.Module._load (module.js:280:25) at Module.require (module.js:362:17) at require (module.js:378:17) at Object.<anonymous> (/Users/feelexit/WebstormProjects/learnnode/node_modules/index.js:1:81) at Module._compile (module.js:449:26) at Object.Module._extensions..js (module.js:467:10) at Module.load (module.js:356:32) at Function.Module._load (module.js:312:12) at Module.runMain (module.js:492:10) feelexits-Mac:node_modules feelexit$

Update to answer chovy's question:

feelexits-Mac:~ feelexit$ npm install npm ERR! install Couldn't read dependencies npm ERR! Error: ENOENT, open '/Users/feelexit/package.json' npm ERR! If you need help, you may report this log at: npm ERR! < npm ERR! or email it to: npm ERR! <> npm ERR! System Darwin 12.2.0 npm ERR! command "/Users/feelexit/nvm/v0.8.20/bin/node" "/Users/feelexit/nvm/v0.8.20/bin/npm" "install" npm ERR! cwd /Users/feelexit npm ERR! node -v v0.8.20 npm ERR! npm -v 1.2.11 npm ERR! path /Users/feelexit/package.json npm ERR! code ENOENT npm ERR! errno 34 npm ERR! npm ERR! Additional logging details can be found in: npm ERR! /Users/feelexit/npm-debug.log npm ERR! not ok code 0
10

20 Answers

It says

Cannot find module 'express'

Do you have express installed? If not then run this.

npm install express

and run your program again.

7

After you do express in your terminal, then do

npm install

To install all the dependencies.

Then you can do node app to run the server.

2

Check if you have installed express module. If not, use this command:

npm install express

and if your node_modules directory is in another place, set NODE_PATH envirnment variable:

set NODE_PATH=your\directory\to\node_modules;%NODE_PATH%
2
npm install --save express

This worked for me. Just run express.js installation again.

0

npm install from within your app directory will fix the issue as it will install everything required

0

Unless you set Node_PATH, the only other option is to install express in the app directory, like npm install express --save. Express may already be installed but node cannot find it for some reason

1

Digging up an old thread here BUT I had this same error and I resolved by navigating to the directory my NodeApp resides in and running npm install -d

2

You have your express module located in a different directory than your project. That is probably the problem since you are trying to require() it locally. Try moving your express module from /Users/feelexit/nvm/node_modules/express to /Users/feelexit/WebstormProjects/learnnode/node_modules/express. This info can give you more detail about node_module file structures.

if youre main file is located at /Users/feelexit/WebstormProjects/learnnode/node_modules/index.js then express needs to be located at /Users/feelexit/WebstormProjects/learnnode/node_modules/node_modules as node always looks for modules in ./node_modules (and its internal folder) when the path dont start with ./ or / (more info here)

i think you miss placed youre main file in the module folder

0

for this scenario run npm install express command using your cmd prompt for the respective folder where you want to run the program. Example I want to run the express module program server.js in F:\nodeSample. So run "npm install express" in that particular folder then run server.js

0

Sometimes there are error while installing the node modules Try this:

  1. Delete node_modules
  2. npm install

Run npm install express body-parser cookie-parser multer --save command in the same directory with your source code nodejs file to resolve this issue. P/s: check your directory after run command to understand more!

In rare cases, npm cache may get corrupt. For me, what worked was:

npm cache clean --force

Generally, the package manager will detect corruption and refetch on its own so this is not usually necessary. However, in my case Windows 10 crashed a few times and I suspect this may have been during a fetch operation. Hope it helps someone!

More information:

1

npm ERR! Error: ENOENT, open '/Users/feelexit/package.json'

This happens due to missing permissions or unlinked files while npm was working.

Meaning, that executing npm as this user doesn't have enough rights to read/write from a file, in this case package.json.

try adding sudo before the entire command - it should resolve.

$ sudo npm install -g express
$ Password:*******

Password would be your admin password of your mac.

-g flag will install this module (express) in the global context of node - meaning node will/should recognize express module from within any js file without having to provide a full path to the module in use.

Hope this helps!!

I had the same problem. My issue was that I have to change to the Node.js project directory on the command line before installing express.

cd /Users/feelexit/WebstormProjects/learnnode/node_modules/

I'm guessing that this is coursework from Colt Steele's Web Development course... I was looking for the same answer as to why I ended up with that error too.. Colt doesn't say so but you take the node_module folder and move into the new folder you're working in... that's what worked for me.

D:\learn\Node.js\node app.js module.js:549 throw err; ^ Error: Cannot find module 'body-parser' at Function.Module._resolveFilename (module.js:547:15) at Function.Module._load (module.js:474:25) at Module.require (module.js:596:17) at require (internal/module.js:11:18)

Sometimes version not match with package.json Fixed the problem by checking the package.json then use the following commands: npm install body-parser@1.13.2 it resolved for me.

I've came across a similar problem and in the end it was a matter of some old dependencies that were messing up my Heroku server.

While at my project's folder I've run:

npm uninstall npm install

I hope it helps

Have you tried

npm install

If you're specifically looking for just express 

npm install --save express

In my case I was trying to run the same as you but using nodemon. The error was the same but the problem was because on my package.json I added app.js instead of just app

"script" : { "dev": "nodemon app" }