After pulling down a module from GitHub and following the instructions to build it, I try pulling it into an existing project using:
> npm install ../faye
This appears to do the trick:
> npm list /home/dave/src/server └─┬ email@example.com ├── firstname.lastname@example.org ├── email@example.com └── firstname.lastname@example.org
But Node.js can't find the module:
> node app.js node.js:201 throw e; // process.nextTick error, or 'error' event on first tick ^ Error: Cannot find module 'faye' at Function._resolveFilename (module.js:334:11) at Function._load (module.js:279:25) at Module.require (module.js:357:17) at require (module.js:368:17) at Object.<anonymous> (/home/dave/src/server/app.js:2:12) at Module._compile (module.js:432:26) at Object..js (module.js:450:10) at Module.load (module.js:351:31) at Function._load (module.js:310:12) at Array.0 (module.js:470:10)
I really want to understand what is going on here, but I'm at a bit of a loss as to where to look next. Any suggestions?
npm install installs the module into the current directory only (in a subdirectory called
node_modules). Is app.js located under
home/dave/src/server/? If not and you want to use the module from any directory, you need to install it globally using
npm install -g.
I usually install most packages locally so that they get checked in along with my project code.
Nowadays you can use package-lock.json file, which is automatically generated when npm modifies your node_modules directory. Therefore you can leave out checking in packages, because the
package-lock.json tracks the exact versions of your node_modules, you're currently using. To install packages from
package-lock.json instead of
package.json use the command
I've received a lot of flak for my response, specifically that I check in the packages that my code depends on. A few days ago, somebody unpublished all of their packages (https://medium.com/@azerbike/i-ve-just-liberated-my-modules-9045c06be67c#.kq9s64clp) which broke React, Babel, and just about everything else. Hopefully it's clear now that if you have production code, you can't rely on NPM actually maintaining your dependencies for you.
I had a very similar issue. Removing the entire
node_modules folder and re-installing worked for me:
rm -rf node_modules npm install