Verquire: versioned require

This module intercepts require to support a syntax which allows loading of a specific version of a Node.js module.

Getting started

Install:

npm i verquire

Use:

require('verquire');

// no changes in loading of native modules
var url = require('url'); 

// no changes in loading of non-versioned user modules
var bar = require('bar'); 

// load version 1.2.3 of foo; see below
var foo = require('[email protected]'); 

Setup and configuration

The verquire module redirects requests for specific module versions to a dedicated directory structure. The directory is identified with VERQUIRE_DIR environment variable, or the _verquire subdirectory of the install location of the verquire module by default. The structure of this directory must follow this pattern:

<VERQUIRE_DIR>
  foo
    1.0.0
      node_modules
        foo
    1.2.3
      node_modules
        foo
    2.0.0
      node_modules
        foo
  bar
    2.1.3
      node_modules
        bar
  ...

Each leaf directory must contain dependency module closure of the respective versioned module. For example, <VERQUIRE_DIR>/foo/1.0.0 can be created and populated a priori as follows:

mkdir -p <VERQUIRE_DIR>/foo/1.0.0
cd <VERQUIRE_DIR>/foo/1.0.0
npm i [email protected]

Listing available versions

You can list available versions of a named module by calling:

var verquire = require('verquire');
console.log(verquire.list('mongodb'));

The list function returns an array of strings indicating the available module versions, or an empty array if the module is not installed.

Debug

The verquire module can optionally track failed module load attempts by dumping relevant information to the console. Set the VERQUIRE_DEBUG=1 environment variable to enable this behavior.

Not supported

• Only exact match of the full module version is supported. No support for semver matching.