Send WhatsApp messages with spoiler tags!
If a message is longer than a certain limit, WhatsApp clients will truncate it and show a "Read more" link instead. By padding a message with 4000 zero-width joiners, we can force this behaviour and emulate a spoiler tag.
Read the full write-up at https://blog.jiayu.co/2018/05/whatsapp-spoilers/.
Ji An