Ghost/core/server/web/shared/utils.js

const url = require('url');

const _private = {};

_private.removeDoubleCharacters = (character, string) => {
    const stringArray = string.split('');

    return stringArray.reduce((newString, currentCharacter, index) => {
        if (
            currentCharacter === character &&
            stringArray[index + 1] === character
        ) {
            return newString;
        }

        return `${newString}${currentCharacter}`;
    }, '');
};

module.exports.removeOpenRedirectFromUrl = function removeOpenRedirectFromUrl(urlString) {
    const parsedUrl = url.parse(urlString);

    return (
        // http://
        (parsedUrl.protocol ? parsedUrl.protocol + '//' : '') +
        (parsedUrl.auth || '') +
        (parsedUrl.host || '') +
        _private.removeDoubleCharacters('/', parsedUrl.path) +
        (parsedUrl.hash || '')
    );
};