https://github.com/tuchk4/magic-require

Correct node require function (according to caller dirname and current cwd) for linked (npm link) or global packages
https://github.com/tuchk4/magic-require

Last synced: 20 days ago
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Correct node require function (according to caller dirname and current cwd) for linked (npm link) or global packages

• Host: GitHub
• URL: https://github.com/tuchk4/magic-require
• Owner: tuchk4
• Created: 2016-01-24T23:52:43.000Z (almost 9 years ago)
• Default Branch: master
• Last Pushed: 2017-07-24T10:02:39.000Z (over 7 years ago)
• Last Synced: 2024-10-11T00:26:27.838Z (about 1 month ago)
• Language: JavaScript
• Homepage:
• Size: 502 KB
• Stars: 5
• Watchers: 2
• Forks: 0
• Open Issues: 2
• Metadata Files:
  • Readme: README.md

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README

        
## The problem

Usually module availability could be checked using native `require` method.

```js

const isExists = false;

try {

  require.resolve('angular')

  isExists = true;

} catch (e) {

    

}

```

But here is problem: I don't want to write `try catch` statements :)

OK. The real problem appears when developing component with auto requiring modules. 

`require` and `require.resolve` will work correctly until component is in local node_modules.

After [npm link](https://docs.npmjs.com/cli/link) (that is very useful while developing npm packages) or if components

is installed as global package - `require` and `require.resolve` will work from global context (at \*nix systems

`/usr/local/lib/node_modules`). 

For example:

I am developing build / server like webpack. And there are loaders (babel-loader, html-loader, json-loader etc).

And I want my builder to require loader automatically when it is needed. So my `node_modules` should be as below:

    /my-work-directory/node_modules

                             |-builder/

                             |-babel-loader/

                             |-html-loader/

                             |-json-loader/

         

In this case if I run `require('babe-loader')` at `builder` component - it will work.

But If I `npm link` my build (for better developing process) or make in global - my `node_modules` will be as below:

    /usr/local/lib/node_modules

                            |-builder/

        

    /my-work-directory/node_modules

                             |-(linked directory) builder/

                             |-babel-loader/

                             |-html-loader/

                             |-json-loader/

And in this case if I run `require('babe-loader')` at `builder` - will be exception `Error: Cannot find module 'babel-loader'`.

This happens because `require` depends on **\_\_dirname** that equals `/usr/local/lib/node_modules/builder` at `builder` component. 

Here is documentation how [modules are loading from node_modules folder](https://nodejs.org/docs/latest/api/modules.html#modules_loading_from_node_modules_folders)

## Solution

`npm install --save magic-require`

First resolve modules according to caller module **\_\_dirname** and if not resolved - try to resolve according to current `process.cwd()`. 

100% supports `package.json` if [loads module as directory](https://nodejs.org/docs/latest/api/modules.html#modules_all_together).

Examples

```js

import magic from 'magic-require';

magic.isExists('babel-loader'); // true

magic.isExists('expose-loader'); // false

magic.resolve('babel-loader'); // ../../../.. /my-work-directory/node_modules/babe-loader/index.js

const BabelLoader = magic('babel-laoder');

```

Available methods

- `isExists(module)` - returns **true** if module exists and **false** - if not.

- `resolve(module)` - returns relative path to requested module from current executing module's **\_\_dirname** or `null`. 

## Community

You are always welcome for ideas and pull requests :)