@aikidosec/firewall/helpers/wrap.js

Zen by Aikido is an embedded Web Application Firewall that autonomously protects Node.js apps against common and critical attacks

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.wrap = wrap;
exports.createWrappedFunction = createWrappedFunction;
exports.isWrapped = isWrapped;
function wrap(module, name, wrapper) {
    if (!module[name]) {
        throw new Error(`no original function ${name} to wrap`);
    }
    if (typeof module[name] !== "function") {
        throw new Error(`original must be a function, instead found: ${typeof module[name]}`);
    }
    const original = module[name];
    const wrapped = createWrappedFunction(original, wrapper);
    defineProperty(module, name, wrapped);
    return wrapped;
}
function createWrappedFunction(original, wrapper) {
    const wrapped = wrapper(original);
    defineProperty(wrapped, "__original", original);
    defineProperty(wrapped, "__wrapped", true);
    // Copy over all properties from the original function to the wrapped one.
    // e.g. fs.realpath.native
    // .inspect("realpath", (args) => {...})
    // We don't want to lose the original function's properties.
    // Most of the functions we're wrapping don't have any properties, so this is a rare case.
    // Inspired by https://github.com/DataDog/dd-trace-js/blob/master/packages/datadog-shimmer/src/shimmer.js#L8
    Object.setPrototypeOf(wrapped, original);
    const props = Object.getOwnPropertyDescriptors(original);
    const keys = Reflect.ownKeys(props);
    for (const key of keys) {
        try {
            // Define the property on the wrapped function, keeping the original property's attributes.
            Object.defineProperty(wrapped, key, props[key]);
        }
        catch {
            //
        }
    }
    return wrapped;
}
// Sets a property on an object, preserving its enumerability.
// This function assumes that the property is already writable.
function defineProperty(obj, name, value) {
    const enumerable = 
    // @ts-expect-error We don't know the type of obj
    !!obj[name] && Object.prototype.propertyIsEnumerable.call(obj, name);
    Object.defineProperty(obj, name, {
        configurable: true,
        enumerable: enumerable,
        writable: true,
        value: value,
    });
}
/**
 * Check if a function is wrapped
 */
function isWrapped(fn) {
    return (fn instanceof Function &&
        "__wrapped" in fn &&
        fn.__wrapped === true &&
        "__original" in fn &&
        fn.__original instanceof Function);
}