require-self

Problem

Many Node.js modules include test and example code in their repos. This code needs to require the module itself.

But whereas modules depending on foobar can write require('foobar'), the test and example code within foobar cannot reliably require itself that way. It must use a relative path like var foobar = require('../..') instead.

Being able to do require('foobar') instead of require('..') has a few advantages. The code can be moved around. Example code is a tad clearer and can be reused in a client module without changes. And if you are authoring in TypeScript, then import foobar = require('foobar') picks up all the static type info from foobar.d.ts, exactly as a client module would see it.

Solutions

Solution A: Do development work inside a node_modules folder

If you ensure your foobar module directory is a direct child of a directory called node_modules, then it can require itself using require('foobar') and Node's module resolution logic will successfully resolve such a call.

However, if you wish to treat your node_modules directories like an artefact that is always safe to clean/delete, this approach is not going to fly. Development work and git repos under node_modules may be inadvertently deleted.

Solution B: Add a self-referencing module to the node_modules folder

A straight-forward solution is to add a file called foobar.js inside foobar's node_modules subdirectory. This file simply contains module.exports = require('..');.

You could automate this step using a simple echo ... command in an npm script, but that won't work cross-platform. Another way is to put the equivalent of the echo... command into a reliable cross-platform node source file, and call that from an npm script.

Solution B is precisely what require-self provides.

Usage

1. Add require-self as a devDependency to your module.
2. Call the require-self bin command in your module's prepare npm script.
3. Run npm install, which will install deps and then run the prepare script. (NOTE: if you are using npm v3 or lower, you'll have to run the prepare script manually, via npm run prepare)

The package.json for your foobar module will end up something like this:

{
    "name": "foobar",
    ...
    "scripts": {
        "build": "...",
        "prepare": "npm run build && require-self"
    },
    "devDependencies": {
        ...
        "require-self": "^0.x"
    }

Now all test and example code in the foobar module can use var foobar = require('foobar');.

License

The MIT License (MIT)

Copyright (c) 2015 Troy Gerwien

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.