refactor(os): Allow AUR helper to replace itself (#3)

README.md

@@ -109,7 +109,7 @@ After installation you're going to want to at least touch these points in your n
 - Passwords
     - ZFS: The password for all datasets underneath `zpool` is `password`.
     - Local `root` account: The local `root` account's password is `password`.
-- Arch User Repository (AUR) helper: We installed [paru](https://github.com/Morganamilo/paru) as our AUR helper, we installed from GitHub via `makepkg -si`.
+- Arch User Repository (AUR) helper: We installed [paru](https://github.com/Morganamilo/paru) as our AUR helper, we installed from GitHub via `makepkg -si` then replaced itself with its [paru-bin](https://aur.archlinux.org/packages/paru-bin) version from AUR.
 - In `/etc/systemd/network/50-wired.network` instead of a DHCP-based network config you can get a static one. The DHCP-based one for reference looks like:
     ```
     ...

setup.sh

@@ -460,7 +460,46 @@ function get_aur_helper () {
 }
 
 function paru_install () {
-    sudo --user build paru -S --noconfirm "${@}"
+    declare -a paru_install_packages
+    [[ "${1}" ]] && while :; do
+        case "${1}" in
+            -[[:alnum:]]*)
+                printf -- '%s\n' \
+                    'Short-form argument '"'${1}'"' not supported for function '"'${FUNCNAME[0]}()'"'. Only known accepted argument' \
+                    'is '"'"'--replace-conflicting'"'"' without a value given. Exiting ...'
+                exit 77
+                ;;
+            --replace-conflicting)
+                pacman_force_yes='true'
+                shift
+                continue
+                ;;
+            --*)
+                printf -- '%s\n' \
+                    'Long-form argument '"'${1}'"' not supported for function '"'${FUNCNAME[0]}()'"'. Only known accepted argument' \
+                    'is '"'"'--replace-conflicting'"'"' without a value given. Exiting ...'
+                exit 77
+                ;;
+            '')
+                # All arguments processed
+                break
+                ;;
+            *)
+                paru_install_packages+=("${1}")
+                shift
+                ;;
+            esac
+    done || {
+        printf -- '%s\n' \
+            'No argument '"'${1}'"' given for function '"'${FUNCNAME[0]}'"'. Exiting ...'
+        exit 77
+    }
+    if [[ "${pacman_force_yes}" ]]; then
+        yes 'y' | sudo --user build paru -S "${paru_install_packages[@]}"
+        unset -v pacman_force_yes
+    else
+        sudo --user build paru -S --noconfirm "${paru_install_packages[@]}"
+    fi
 }
 
 function keep_initiramfs_root_only_rw () {
@@ -525,6 +564,7 @@ function install_os_in_chroot () {
     unleash_makepkg
     add_motd_getting_started_msg
     get_aur_helper
+    paru_install --replace-conflicting 'paru-bin'
     paru_install 'zfs-dkms' 'zfs-utils'
     hwclock --systohc
     locale-gen