node_modules/err-code/index.js

'use strict';

function assign(obj, props) {
    for (const key in props) {
        Object.defineProperty(obj, key, {
            value: props[key],
            enumerable: true,
            configurable: true,
        });
    }

    return obj;
}

function createError(err, code, props) {
    if (!err || typeof err === 'string') {
        throw new TypeError('Please pass an Error to err-code');
    }

    if (!props) {
        props = {};
    }

    if (typeof code === 'object') {
        props = code;
        code = undefined;
    }

    if (code != null) {
        props.code = code;
    }

    try {
        return assign(err, props);
    } catch (_) {
        props.message = err.message;
        props.stack = err.stack;

        const ErrClass = function () {};

        ErrClass.prototype = Object.create(Object.getPrototypeOf(err));

        return assign(new ErrClass(), props);
    }
}

module.exports = createError;