Find URLs in text and create links out of it.

urlify.js

function urlify(text) {
    const hyperlink = /<a [^>]+>([\w\d./=:"-]+)<\/a>/g
    const urlRegex = /(https?:\/\/|www\.)([\w\d./-]+)/g

    return text.replace(/(?:\r\n|\r|\n)/g, '<br>')
        .replace(hyperlink, '$1')
        .replace(urlRegex, (url, protoOrSub, domain) => {
            domain = domain.replace(/\/$/, '')

            if (protoOrSub.match(/https?/)) {
                return `<a href="${protoOrSub}${domain}" target="_blank">${domain}</a>`
            } else if (protoOrSub === 'www.') {
                return `<a href="http://www.${domain}" target="_blank">www.${domain}</a>`
            } else {
                return url
            }
        }) 
}

console.log(urlify('Link: http://www.domain1.com/clients/,'))
console.log(urlify('Link: https://www.domain2.com/clients?'))
console.log(urlify('Link: www.domain3.com/clients'))
console.log(urlify('Link: <a href="https://www.domain4.com/clients" target="_blank">https://www.domain4.com/clients</a>!'))