Security News
ESLint is Now Language-Agnostic: Linting JSON, Markdown, and Beyond
ESLint has added JSON and Markdown linting support with new officially-supported plugins, expanding its versatility beyond JavaScript.
require-in-the-middle
Advanced tools
The require-in-the-middle package allows for the interception and modification of Node.js module loading. This can be particularly useful for instrumentation, logging, or modifying module behavior at runtime without altering the original module code.
Intercepting module loading
This feature allows you to intercept the loading of specific modules (e.g., 'http') and execute custom logic, such as logging when a module is loaded. The callback function receives the exports of the module, the name of the module, and the base directory.
const hook = require('require-in-the-middle');
hook(['http'], { internals: true }, (exports, name, basedir) => {
console.log(`Module loaded: ${name}`);
return exports;
});
Modifying module exports
This demonstrates how to modify the exports of a module, in this case, 'express'. It wraps the original express function in a new function that logs a message every time it is called before proceeding with the original behavior.
const hook = require('require-in-the-middle');
hook(['express'], (exports, name) => {
const originalFunction = exports;
function modifiedFunction() {
console.log('Express function called');
return originalFunction.apply(this, arguments);
}
return modifiedFunction;
});
Shimmer is a package for wrapping and replacing Node.js module methods. It is similar to require-in-the-middle in its ability to modify module behavior at runtime, but it focuses more on individual method manipulation rather than intercepting module loading.
Proxyquire allows for the overriding of modules during testing by intercepting 'require' calls. It is similar to require-in-the-middle in that it manipulates module loading, but it is specifically designed for testing scenarios, making it easier to mock modules.
Hook into the Node.js require
function. This allows you to modify
modules on-the-fly as they are being required.
npm install require-in-the-middle --save
var path = require('path')
var hook = require('require-in-the-middle')
// Hook into the express and mongodb module
hook(['express', 'mongodb'], function (exports, name, basedir) {
var version = require(path.join(basedir, 'package.json')).version
console.log('loading %s@%s', name, version)
// expose the module version as a property on its exports object
exports._version = version
// whatever you return will be returned by `require`
return exports
})
The require-in-the-middle module exposes a single function:
function ([modules][, options], onrequire) {}
modules
<string[]> An optional array of module names to limit which modules
trigger a call of the onrequire
callback. If specified, this must be the
first argument.options
<Object> An optional object containing fields that change when the
onrequire
callback is called. If specified, this must be the second
argument.
options.internals
<boolean> Specifies whether onrequire
should be called
when module-internal files are loaded; defaults to false
.onrequire
<Function> The function to call when a module is required.Supply a callback function as the last argument. This function will be
called the first time a module is required. The onrequire
function is
called with three arguments:
exports
<Object> The value of the module.exports
property that would
normally be exposed by the required module.name
<string> The name of the module being required. If options.internals
was set to true
, the path of module-internal files that are loaded
(relative to basedir
) will be appended to the module name, separated by
path.sep
.basedir
<string> The directory where the module is located, or undefined
for core modules.Return the value you want the module to expose (normally the exports
argument).
MIT
FAQs
Module to hook into the Node.js require function
The npm package require-in-the-middle receives a total of 6,661,739 weekly downloads. As such, require-in-the-middle popularity was classified as popular.
We found that require-in-the-middle demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 2 open source maintainers collaborating on the project.
Did you know?
Socket for GitHub automatically highlights issues in each pull request and monitors the health of all your open source dependencies. Discover the contents of your packages and block harmful activity before you install or update your dependencies.
Security News
ESLint has added JSON and Markdown linting support with new officially-supported plugins, expanding its versatility beyond JavaScript.
Security News
Members Hub is conducting large-scale campaigns to artificially boost Discord server metrics, undermining community trust and platform integrity.
Security News
NIST has failed to meet its self-imposed deadline of clearing the NVD's backlog by the end of the fiscal year. Meanwhile, CVE's awaiting analysis have increased by 33% since June.