为什么使用“ npm install -g themodule”安装的模块不起作用？

Question

I'm working on a Windows environment.

I install a module with

npm install -g themodule

The module is installed, I can see it with the command

npm list -g --depth 0

But when I do a require("themodule"), I get an the error:

Error: Cannot find module 'themodule'

I assume it's a rookie mistake but I don't see it.

Did someone have an explanation?

Answer 1

You are globally installing the package but not making it available in your node_modules folder for your project..

you need to give

npm i --save-dev themodule // this installs a devDependency for development purpose

npm i --save themodule // this installs a dependency and is for production ready.

(please see.. npm i is equivalent for npm install )

--

in short.. devDependencies object in package.json will have all the development related packages and dependency object will have production ready packages..

So.. to summon this.. when you say require('themodule') , then node checks whether this dependency package is available in node_modules folder or not..

so in your case it is not and that is the reason for the error..

Now, add the dependency package details in the package.json or do an npm i --save themodule