chrysalis: set passthru.updateScript

pkgs/by-name/ch/chrysalis/package.nix

@@ -38,6 +38,8 @@ in appimageTools.wrapType2 rec {
     install -Dm444 ${appimageContents}/usr/share/icons/hicolor/256x256/chrysalis.png -t $out/share/pixmaps
   '';
 
+  passthru.updateScript = ./update.sh;
+
   meta = with lib; {
     description = "A graphical configurator for Kaleidoscope-powered keyboards";
     homepage = "https://github.com/keyboardio/Chrysalis";

pkgs/by-name/ch/chrysalis/update.sh

@@ -0,0 +1,16 @@
+#! /usr/bin/env nix-shell
+#! nix-shell -i bash --pure -p curl cacert jq
+
+set -euo pipefail
+
+cd "$(dirname "${BASH_SOURCE[0]}")"
+DRV_DIR="$PWD"
+
+relinfo=$(curl -sL 'https://api.github.com/repos/keyboardio/chrysalis/releases' | jq 'map(select(.prerelease == false)) | max_by(.tag_name)')
+newver=$(echo "$relinfo" | jq --raw-output '.tag_name' | sed 's|^v||')
+hashurl=$(echo "$relinfo" | jq --raw-output '.assets[] | select(.name == "latest-linux.yml").browser_download_url')
+newhash=$(curl -sL "$hashurl" | grep -Po '^sha512: \K.*')
+
+sed -i package.nix \
+    -e "/^  version =/ s|\".*\"|\"$newver\"|" \
+    -e "/sha512-/ s|\".*\"|\"sha512-$newhash\"|" \