livecheck: split cask versions into sub-versions

Library/Homebrew/livecheck/livecheck.rb

@@ -4,6 +4,7 @@
 require "livecheck/error"
 require "livecheck/skip_conditions"
 require "livecheck/strategy"
+require "livecheck/version"
 require "ruby-progressbar"
 require "uri"
 
@@ -150,7 +151,7 @@ def run_checks(
         end
 
         current_str = current.to_s
-        current = actual_version(formula_or_cask, current)
+        current = LivecheckVersion.create(formula_or_cask, current)
 
         latest = if formula&.head_only?
           formula.head.downloader.fetch_last_commit
@@ -176,7 +177,7 @@ def run_checks(
         end
 
         latest_str = latest.to_s
-        latest = actual_version(formula_or_cask, latest)
+        latest = LivecheckVersion.create(formula_or_cask, latest)
 
         is_outdated = if formula&.head_only?
           # A HEAD-only formula is considered outdated if the latest upstream
@@ -546,7 +547,7 @@ def latest_version(formula_or_cask, json: false, full_name: false, verbose: fals
         next if match_version_map.blank?
 
         version_info = {
-          latest: Version.new(match_version_map.values.max_by { |v| actual_version(formula_or_cask, v) }),
+          latest: Version.new(match_version_map.values.max_by { |v| LivecheckVersion.create(formula_or_cask, v) }),
         }
 
         if json && verbose
@@ -570,17 +571,5 @@ def latest_version(formula_or_cask, json: false, full_name: false, verbose: fals
 
       nil
     end
-
-    sig { params(formula_or_cask: T.any(Formula, Cask::Cask), version: Version).returns(Version) }
-    def actual_version(formula_or_cask, version)
-      case formula_or_cask
-      when Formula
-        version
-      when Cask::Cask
-        Version.new(Cask::DSL::Version.new(version.to_s).before_comma)
-      else
-        T.absurd(formula_or_cask)
-      end
-    end
   end
 end

Library/Homebrew/livecheck/version.rb

@@ -0,0 +1,69 @@
+# typed: strict
+# frozen_string_literal: true
+
+module Homebrew
+  module Livecheck
+    # A formula or cask version, split into its component sub-versions.
+    #
+    # @api private
+    class LivecheckVersion
+      extend T::Sig
+
+      include Comparable
+
+      sig { params(formula_or_cask: T.any(Formula, Cask::Cask), version: Version).returns(LivecheckVersion) }
+      def self.create(formula_or_cask, version)
+        versions = case formula_or_cask
+        when Formula
+          [version]
+        when Cask::Cask
+          version.to_s.split(/[,:]/).map { |s| Version.new(s) }
+        else
+          T.absurd(formula_or_cask)
+        end
+        new(versions)
+      end
+
+      sig { returns(T::Array[Version]) }
+      attr_reader :versions
+
+      sig { params(versions: T::Array[Version]).void }
+      def initialize(versions)
+        @versions = versions
+      end
+
+      sig { params(other: T.untyped).returns(T.nilable(Integer)) }
+      def <=>(other)
+        return unless other.is_a?(LivecheckVersion)
+
+        lversions = versions
+        rversions = other.versions
+        max = [lversions.count, rversions.count].max
+        l = r = 0
+
+        while l < max
+          a = lversions[l] || Version::NULL
+          b = rversions[r] || Version::NULL
+
+          if a == b
+            l += 1
+            r += 1
+            next
+          elsif !a.null? && b.null?
+            return 1 if a > Version::NULL
+
+            l += 1
+          elsif a.null? && !b.null?
+            return -1 if b > Version::NULL
+
+            r += 1
+          else
+            return a <=> b
+          end
+        end
+
+        0
+      end
+    end
+  end
+end