am-i-a-dependency

Check if the package is being installed by another package

Problem

Often you want to run a post install script that does something. Yet, this postinstall script will run even in the module itself. Thus we need a simple way to determine if we are installing our dependencies or installing the current module as a dependency of some other module. This can be explained by a difference in commands below

npm i      -> we are installing our dependencies
npm i foo  -> module "foo" is being installed as a dependency

If module foo has a postinstall script, it can use this module am-i-a-dependency to determine if it should be executed.

Install

Requires Node version 4 or above.

npm install --save am-i-a-dependency

Use

Imagine a postinstall script

{
  "scripts": {
    "postinstall": "node something.js"
  }
}

Then inside something.js we can check

// something.js
const amDependency = require('am-i-a-dependency')()
if (amDependency) {
  // yes, do something interesting
  // someone is executing "npm install foo"
} else {
  // we are inside "foo" itself, so nothing to do
}

Small print

Author: Gleb Bahmutov <[e-mail]> © 2017

• @bahmutov
• glebbahmutov.com
• blog

License: MIT - do anything with the code, but don't blame me if it does not work.

Support: if you find any problems with this module, email / tweet / open issue on Github

MIT License

Copyright (c) 2017 Gleb Bahmutov <[e-mail]>

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.