yay paccache hooks

cacheremove.hook

[Trigger]
Operation = Remove
Type = Package
Target = *

[Action]
Description = Clearing cache...
When = PostTransaction
Exec = /home/<user>/.local/bin/tools/removehook

cacheupgrade.hook

[Trigger]
Operation = Upgrade
Type = Package
Target = *

[Action]
Description = Clearing cache...
When = PostTransaction
Exec = /home/<user>/.local/bin/tools/upgradehook

removehook

#!/bin/sh
yaycache="$(find "$HOME"/.cache/yay -maxdepth 1 -type d | awk '{ print "-c " $1 }' | tail -n +2)"
yayremoved=$(/usr/bin/paccache -ruvk0 $yaycache | sed '/\.cache\/yay/!d' | cut -d \' -f2 | rev | cut -d / -f2- | rev)
[ -z $yayremoved ] || echo "==> Remove all uninstalled package folders" &&
echo $yayremoved | xargs -rt rm -r

upgradehook

#!/bin/sh
yaycache="$(find "$HOME"/.cache/yay -maxdepth 1 -type d | awk '{ print "-c " $1 }' | tail -n +2)"
echo "==> Keep last 2 installed versions"
/usr/bin/paccache -rvk2 -c /var/cache/pacman/pkg $yaycache

This is what I've been using:

[Trigger]
Operation = Upgrade
Operation = Remove
Type = Package
Target = *

[Action]
Description = Clearing cache...
When = PostTransaction
Exec = /usr/bin/bash -c 'yay=$(find /home/$SUDO_USER/.cache/yay -mindepth 1 -maxdepth 1 -type d -exec echo -c {} \;); paccache -rk2 -c /var/cache/pacman/pkg $yay; paccache -ruk0 $yay; find /home/$SUDO_USER/.cache/yay -mindepth 1 -maxdepth 1 -type d -exec bash -c "compgen -G {}/*.pkg.tar.zst > /dev/null || rm -r {}" \;'

Edit: Actually now that I'm thinking about it, parsing paccache -ru isn't reliable because it will remove e.g. /home/user/.cache/yay/mutter-performance/mutter-performance-docs-1:44.3-2-x86_64.pkg.tar.zst (because mutter-performance-docs is not installed) thus removing /home/user/.cache/yay/mutter-performance even though mutter-performance is installed.