Merge pull request #14262 from nandahkrishna/resource-livecheck-formula-latest

Enable use of latest formula version in resource `livecheck` URLs

Library/Homebrew/formula.rb

@@ -3278,6 +3278,7 @@ class Formula
     def livecheck(&block)
       return @livecheck unless block
 
+      include Homebrew::Livecheck::Constants
       @livecheckable = true
       @livecheck.instance_eval(&block)
     end

Library/Homebrew/livecheck.rb

@@ -1,6 +1,8 @@
 # typed: true
 # frozen_string_literal: true
 
+require "livecheck/constants"
+
 # The {Livecheck} class implements the DSL methods used in a formula's, cask's
 # or resource's `livecheck` block and stores related instance variables. Most
 # of these methods also return the related instance variable when no argument

Library/Homebrew/livecheck/constants.rb

@@ -0,0 +1,14 @@
+# typed: true
+# frozen_string_literal: true
+
+module Homebrew
+  module Livecheck
+    # The {Constants} module provides constants that are intended to be used
+    # in `livecheck` block values (e.g. `url`, `regex`).
+    module Constants
+      # A placeholder string used in resource `livecheck` block URLs that will
+      # be replaced with the latest version from the main formula check.
+      LATEST_VERSION = "<FORMULA_LATEST_VERSION>"
+    end
+  end
+end

Library/Homebrew/livecheck/livecheck.rb

@@ -1,6 +1,7 @@
 # typed: true
 # frozen_string_literal: true
 
+require "livecheck/constants"
 require "livecheck/error"
 require "livecheck/livecheck_version"
 require "livecheck/skip_conditions"
@@ -295,6 +296,7 @@ module Homebrew
             else
               res_version_info = resource_version(
                 resource,
+                latest.to_s,
                 json:    json,
                 debug:   debug,
                 quiet:   quiet,
@@ -836,15 +838,17 @@ module Homebrew
     # version information. Returns nil if a latest version couldn't be found.
     sig {
       params(
-        resource: Resource,
-        json:     T::Boolean,
-        debug:    T::Boolean,
-        quiet:    T::Boolean,
-        verbose:  T::Boolean,
+        resource:       Resource,
+        formula_latest: String,
+        json:           T::Boolean,
+        debug:          T::Boolean,
+        quiet:          T::Boolean,
+        verbose:        T::Boolean,
       ).returns(Hash)
     }
     def resource_version(
       resource,
+      formula_latest,
       json: false,
       debug: false,
       quiet: false,
@@ -874,12 +878,11 @@ module Homebrew
       checked_urls = []
       # rubocop:disable Metrics/BlockLength
       urls.each_with_index do |original_url, i|
+        url = original_url.gsub(Constants::LATEST_VERSION, formula_latest)
+
         # Only preprocess the URL when it's appropriate
-        url = if STRATEGY_SYMBOLS_TO_SKIP_PREPROCESS_URL.include?(livecheck_strategy)
-          original_url
-        else
-          preprocess_url(original_url)
-        end
+        url = preprocess_url(url) unless STRATEGY_SYMBOLS_TO_SKIP_PREPROCESS_URL.include?(livecheck_strategy)
+
         next if checked_urls.include?(url)
 
         strategies = Strategy.from_url(