Sharing node_modules folder with multiple projects

[eliasuardi]

Hello.

As the title says I was wondering if it were possible to use the same modules folder for multiple projects so that I don't have to continuously install them using the command prompt.

Is it possible? If so how do I proceed?

Thanks.
Elia

[chungngoops]

Yes, it possible>
I found the info in Node's document:
https://nodejs.org/api/modules.html#modules_loading_from_node_modules_folders

If the module identifier passed to require() is not a core module, and does not begin with '/', '../', or './', then Node.js starts at the parent directory of the current module, and adds /node_modules, and attempts to load the module from that location. Node will not append node_modules to a path already ending in node_modules.

If it is not found there, then it moves to the parent directory, and so on, until the root of the file system is reached.

For example, if the file at '/home/ry/projects/foo.js' called require('bar.js'), then Node.js would look in the following locations, in this order:

/home/ry/projects/node_modules/bar.js
/home/ry/node_modules/bar.js
/home/node_modules/bar.js
/node_modules/bar.js
This allows programs to localize their dependencies, so that they do not clash.

It is possible to require specific files or sub modules distributed with a module by including a path suffix after the module name. For instance require('example-module/path/to/file') would resolve path/to/file relative to where example-module is located. The suffixed path follows the same module resolution semantics.

[eliasuardi]

So how should I structure the scripts element in the package.json of my projects?
This is one of them:

{
  "name": "stateless-functional-components",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
      "build": "webpack",
      "start": "webpack-dev-server"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "babel-core": "^6.25.0",
    "babel-loader": "^7.0.0",
    "babel-preset-es2015": "^6.24.1",
    "babel-preset-react": "^6.24.1",
    "react": "^15.6.1",
    "react-dom": "^15.6.1"
  },
  "devDependencies": {
    "html-webpack-plugin": "^2.28.0",
    "webpack": "^2.6.1",
    "webpack-dev-server": "^2.4.5"
  }
}

I tried executing npm run build but I get this error:

> webpack

'webpack' is not recognized as an internal or external command,
operable program or batch file.
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! stateless-functional-components@1.0.0 build: `webpack`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the stateless-functional-components@1.0.0 build script.
npm WARN Local package.json exists, but node_modules missing, did you mean to install?

[chungngoops]

I think you should create a project structure like this:

-Projects
--node_modules
--myproject1
---sub-project
--myproject2

then you install your npm package by run npm install with --save arg then it will be automatically append to your package.json.

[eliasuardi]

Thank you for the response.
So what I've done is:

1. execute npm init -y in my project folder
2. added manually dependencies to package.json:

• babel-core
• babel-loader
• babel-preset-es2015
• babel-preset-react
• react
• react-dom
• html-webpack-plugin
• webpack
• webpack-dev-server

3. executed npm install --save arg
   I've noticed that all it adds to the package.json is "arg": "0.0.1".

After these steps I still get the error.
Is there something I'm doing wrong?

Thanks.
Elia

[chungngoops]

I think you misunderstood me.
should be like this:

1. run npm init
2. install your npm packages, like npm install --save webpack

then it should work.

[eliasuardi]

Oh sorry about that.
I tried that but npm install --save <package> creates a local node_modules directory even though there is one in the parent directory.
So now my project structure is:

-Codecademy
--node_modules
--project1
---node_modules

[chungngoops]

For me, I put the file package.json for all project1, project2.. under Codecademy, then install npm packages, so when I run npm install --save <npm-package> it creates node_modules under Codecademy folder only.

-Codecademy
--node_modules
--package.json
--project1
---app.js

[Opty1712]

chungngoops

How do you execute npm run xxxx inside project1?
I've installed node_modules in upper dir, but when I call npm run dev I get an error: can not find module 'webpack'

[ORESoftware]

You could also use symlinks, using npm link, etc.

[Opty1712]

as far as I know - npm link is only for 1 package, but I talk about folder with ~1000 modules...

[ORESoftware]

say you have this:

 HOME/
   projects/
     node_modules/
     project_a/package.json
     project_b/package.json
     project_c/package.json

The best thing to do is use NODE_PATH env variable to include the node_modules directory in the projects folder. It's simple:

cd "$HOME/projects/project_a"
NODE_PATH="$HOME/projects/node_modules"  node app.js

cd "$HOME/projects/project_b"
NODE_PATH="$HOME/projects/node_modules"  node app.js

cd "$HOME/projects/project_c"
NODE_PATH="$HOME/projects/node_modules"  node app.js

try that. NODE_PATH is an env variable that's empty by default. If NODE_PATH is not empty, it's safer to do:

NODE_PATH="$NODE_PATH:$HOME/projects/node_modules" node app.js

[ORESoftware]

that being said, babel dependencies should be shared by default.

see # 15 here:
https://medium.com/@the1mills/node-js-wicked-tricks-from-the-oss-battlefield-a9e71c5c791d

Given the directory structure I mentioned above, Babel will reach up the directory tree and will be able to see:

$HOME/projects/node_modules

[ORESoftware]

[Opty1712]

ORESoftware thank you for the assistance but may be it is not working under windows?

My structure is:

c:\WORK\tmp\test_folder\node_modules\
c:\WORK\tmp\test_folder\project1\package.json
c:\WORK\tmp\test_folder\project2\package.json

I've tried following:

LOCATION: sbt-edunov-ab@SBT-C0APQD8 MINGW64 /c/WORK/tmp/test_folder/project1
COMMAND: $ NODE_PATH="/C/Work/tmp/test_folder/node_modules" echo $NODE_PATH
RESULT: /C/Work/tmp/test_folder/node_modules

cd /C/Work/tmp/test_folder/node_modules - works good, it seems there are no problems with PATH

LOCATION: sbt-edunov-ab@SBT-C0APQD8 MINGW64 /c/WORK/tmp/test_folder/project1
COMMAND: $ NODE_PATH="/C/Work/tmp/test_folder/node_modules"  node ./webpack/configs/dev.middleware.js
RESULT:  module.js:471
    throw err;
    ^

Error: Cannot find module 'webpack'
    at Function.Module._resolveFilename (module.js:469:15)
    at Function.Module._load (module.js:417:25)
    at Module.require (module.js:497:17)
    at require (internal/module.js:20:19)
    at Object.<anonymous> (C:\WORK\tmp\test_folder\project1\webpack\configs\dev.
middleware.js:3:15)
    at Module._compile (module.js:570:32)
    at Object.Module._extensions..js (module.js:579:10)
    at Module.load (module.js:487:32)
    at tryModuleLoad (module.js:446:12)
    at Function.Module._load (module.js:438:3)