add melonloader

packages/melonloader/update.sh

@@ -0,0 +1,20 @@
+#!/usr/bin/env nix-shell
+#!nix-shell -I nixpkgs=./. -i bash -p curl jq common-updater-scripts
+#shellcheck shell=bash
+
+# Implementation lovingly referenced and adapted from cavalier package's update.sh
+
+set -eu -o pipefail
+
+version=$(curl -s ${GITHUB_TOKEN:+-u ":$GITHUB_TOKEN"} \
+    https://api.github.com/repos/LavaGang/MelonLoader.Installer/releases/latest | jq -e -r .tag_name)
+old_version=$(nix-instantiate --eval -A melonloader-installer.version | jq -e -r)
+
+if [[ $version == "$old_version" ]]; then
+    echo "New version same as old version, nothing to do." >&2
+    exit 0
+fi
+
+update-source-version melonloader-installer "$version"
+
+$(nix-build -A melonloader-installer.fetch-deps --no-out-link) "$(dirname -- "${BASH_SOURCE[0]}")/deps.json"