Add CurseForge release workflow

scripts/get_spigot_versions.sh

@@ -0,0 +1,56 @@
+#!/bin/bash
+#
+# Copyright (C) 2011-2021 lishid. All rights reserved.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, version 3.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+
+# Note that this script is designed for use in GitHub Actions, and is not
+# particularly robust nor configurable. Run from project parent directory.
+
+# Use a nameref as a cache - maven evaluation is pretty slow.
+# Re-calling the script and relying on it to handle caching is way easier than passing around info.
+declare -a spigot_versions
+
+# We don't care about concatenation - either it's not null and we return or it's null and we instantiate.
+# shellcheck disable=SC2199
+if [[ ${spigot_versions[@]} ]]; then
+  for spigot_version in "${spigot_versions[@]}"; do
+    echo "$spigot_version"
+  done
+  return
+fi
+
+# Pull Spigot dependency information from Maven.
+modules=$(mvn help:evaluate -Dexpression=project.modules -q -DforceStdout -P all -pl internal | grep -oP '(?<=<string>)(.*)(?=<\/string>)')
+
+declare -n versions="spigot_versions"
+
+for module in "${modules[@]}"; do
+  # Get number of dependencies declared in pom of specified internal module.
+  max_index=$(mvn help:evaluate -Dexpression=project.dependencies -q -DforceStdout -P all -pl internal/"$module" | grep -c "<dependency>")
+
+  for ((i=0; i < max_index; i++)); do
+    # Get artifactId of dependency.
+    artifact_id=$(mvn help:evaluate -Dexpression=project.dependencies["$i"].artifactId -q -DforceStdout -P all -pl internal/"$module")
+
+    # Ensure dependency is Spigot.
+    if [[ "$artifact_id" == spigot ]]; then
+      # Get Spigot version.
+      spigot_version=$(mvn help:evaluate -Dexpression=project.dependencies["$i"].version -q -DforceStdout -P all -pl internal/"$module")
+      versions+=("$spigot_version")
+      echo "$spigot_version"
+      break
+    fi
+  done
+done