require-at

Allow you to call require or require.resolve pretending that you are at another directory.

Purpose

Given the directory structure below with two NodeJS apps:

app1
|-+ foo
| +-- index.js
| +--+ node_modules
|    +--+ x 
|       + ...
app2
|-+ bar
| +-- index.js
| +--+ node_modules
|    +--+ y
|       + ...

When you call require("x") in /app1/foo/index.js, NodeJS will search and find module x there.

Now from the same file, if you want to resolve the module y under the directory /app2/bar, you have to use an absolute or relative path directly pointing to y, and you may have to do some searching, probably re-implementing Node's module searching algorithm if you don't know exactly where y could be.

However, in the file /app2/bar/index.js, it can just do require("y") and Node would automatically find the module for it, because that file is at the location where y is under.

What if from the file /app1/foo/index.js, you can call require as if you were at the directory /app2/bar, then you would be able to utilize Node's module searching automatically.

To achieve this, most other implementations choose to re-implement Node's module searching algorithm.

This module's approach is to tap into Node's module and let it do the work.

Install

$ npm install require-at --save

Usage

A single function is exported.

requireAt(dir, [request])

• If you call it with just dir, then it returns a require function that's been binded to the directory dir. You can use it to load any module as if you are at dir.
  • You can also call require.resolve with the same effect.
• If you call it with dir and a request, then it will load and return the module request as if at dir.

Example

const requireAt = require("require-at");

// get back a require binded to /another/dir

const requireAtAnother = requireAt("/another/dir/");
const modXPath = requireAtAnother.resolve("modX");
const modX = requireAtAnother("modX");

// load modY at /another/yet/dir directly

const modY = requireAt("/another/yet/dir", "modY");

License

Apache-2.0 © Joel Chen