Like all loaded components/visible items in Spotify.

LazyLiker.js

// Copy paste into console, scroll to bottom of playlist/album
// type "likeAll()" in console, and scroll up and repeat.
// Could use a timeout and just keep repeating as you scroll, 
// but this is quick and dirty and works well enough.

function likeAll(){
x = [...document.getElementsByClassName("spoticon-heart-16")].reverse()
x.forEach( (item)=>{
    item.parentElement.click()
    console.log("Liking a track")
    console.log(item)
})
}