Fix formulae method loading

Co-authored-by: nandahkrishna <me@nandahkrishna.com>

Library/Homebrew/formula.rb

@@ -392,11 +392,6 @@ class Formula
   # @see .livecheckable?
   delegate livecheckable?: :"self.class"
 
-  # The service specification for the software.
-  # @!method service
-  # @see .service=
-  delegate service: :"self.class"
-
   # Is a service specification defined for the software?
   # @!method service?
   # @see .service?
@@ -973,6 +968,13 @@ class Formula
     prefix/"#{plist_name}.plist"
   end
 
+  # The service specification of the software.
+  def service
+    return Homebrew::Service.new(self, &self.class.service) if service?
+
+    nil
+  end
+
   # @private
   delegate plist_manual: :"self.class"
 
@@ -2397,7 +2399,7 @@ class Formula
     # It returns true when a service block is present in the {Formula} and
     # false otherwise, and is used by service.
     def service?
-      @service.present?
+      @service_block.present?
     end
 
     # The `:startup` attribute set by {.plist_options}.
@@ -2874,10 +2876,9 @@ class Formula
     #   run [opt_bin/"foo"]
     # end</pre>
     def service(&block)
-      @service ||= Homebrew::Service.new(self)
-      return @service unless block
+      return @service_block unless block
 
-      @service.instance_eval(&block)
+      @service_block = block
     end
 
     # Defines whether the {Formula}'s bottle can be used on the given Homebrew

Library/Homebrew/service.rb

@@ -7,16 +7,18 @@ module Homebrew
   # also return the related instance variable when no argument is provided.
   class Service
     extend T::Sig
+    extend Forwardable
 
     RUN_TYPE_IMMEDIATE = "immediate"
     RUN_TYPE_INTERVAL = "interval"
     RUN_TYPE_CRON = "cron"
 
     # sig { params(formula: Formula).void }
-    def initialize(formula)
+    def initialize(formula, &block)
       @formula = formula
       @run_type = RUN_TYPE_IMMEDIATE
       @environment_variables = {}
+      @service_block = block
     end
 
     sig { params(command: T.nilable(T.any(T::Array[String], String, Pathname))).returns(T.nilable(Array)) }
@@ -109,47 +111,14 @@ module Homebrew
       end
     end
 
-    # The directory where the formula's variable files should be installed.
-    # This directory is not inside the `HOMEBREW_CELLAR` so it persists
-    # across upgrades.
-    sig { returns(Pathname) }
-    def var
-      HOMEBREW_PREFIX/"var"
-    end
-
-    # The directory where the formula's configuration files should be installed.
-    # Anything using `etc.install` will not overwrite other files on e.g. upgrades
-    # but will write a new file named `*.default`.
-    # This directory is not inside the `HOMEBREW_CELLAR` so it persists
-    # across upgrades.
-    sig { returns(Pathname) }
-    def etc
-      HOMEBREW_PREFIX/"etc"
-    end
-
-    # The directory where the formula's binaries should be installed.
-    # This is symlinked into `HOMEBREW_PREFIX` after installation or with
-    # `brew link` for formulae that are not keg-only.
-    sig { returns(Pathname) }
-    def opt_bin
-      opt_prefix/"bin"
-    end
-
-    # The directory where the formula's binaries should be installed.
-    # This is symlinked into `HOMEBREW_PREFIX` after installation or with
-    # `brew link` for formulae that are not keg-only.
-    sig { returns(Pathname) }
-    def opt_sbin
-      opt_prefix/"sbin"
-    end
-
-    # A stable path for this formula, when installed. Contains the formula name
-    # but no version number. Only the active version will be linked here if
-    # multiple versions are installed.
-    sig { returns(Pathname) }
-    def opt_prefix
-      HOMEBREW_PREFIX/"opt/#{@formula.name}"
-    end
+    delegate [ # rubocop:disable Layout/HashAlignment
+      :bin,
+      :var,
+      :etc,
+      :opt_bin,
+      :opt_sbin,
+      :opt_prefix,
+    ] => :@formula
 
     sig { returns(String) }
     def std_service_path_env
@@ -160,7 +129,9 @@ module Homebrew
     # @return [String]
     sig { returns(String) }
     def to_plist
-      clean_command = @run.select {|i| i.is_a?(Pathname)}
+      instance_eval(&@service_block)
+
+      clean_command = @run.select { |i| i.is_a?(Pathname) }
                           .map(&:to_s)
 
       base = {

Library/Homebrew/test/formula_spec.rb

@@ -704,22 +704,17 @@ describe Formula do
   specify "#service" do
     f = formula do
       url "https://brew.sh/test-1.0.tbz"
-      service do
-        run [opt_bin/"beanstalkd"]
-        run_type :immediate
-        error_log_path var/"log/beanstalkd.error.log"
-        log_path var/"log/beanstalkd.log"
-        working_dir var
-        keep_alive true
-      end
     end
 
-    expect(f.service.run).to eq([HOMEBREW_PREFIX/"opt/bin/beanstalkd"])
-    expect(f.service.error_log_path).to eq("#{HOMEBREW_PREFIX}/var/log/beanstalkd.error.log")
-    expect(f.service.log_path).to eq("#{HOMEBREW_PREFIX}/var/log/beanstalkd.log")
-    expect(f.service.working_dir).to eq("#{HOMEBREW_PREFIX}/var")
-    expect(f.service.keep_alive).to eq(true)
-    expect(f.service.run_type).to eq("immediate")
+    f.class.service do
+      run [opt_bin/"beanstalkd"]
+      run_type :immediate
+      error_log_path var/"log/beanstalkd.error.log"
+      log_path var/"log/beanstalkd.log"
+      working_dir var
+      keep_alive true
+    end
+    expect(f.service).not_to eq(nil)
   end
 
   specify "service uses simple run" do
@@ -730,7 +725,7 @@ describe Formula do
       end
     end
 
-    expect(f.service.run).to eq([HOMEBREW_PREFIX/"opt/bin/beanstalkd"])
+    expect(f.service).not_to eq(nil)
   end
 
   specify "dependencies" do

Library/Homebrew/test/service_spec.rb

@@ -15,12 +15,10 @@ describe Homebrew::Service do
   let(:spec) { :stable }
   let(:f) { klass.new(name, path, spec) }
 
-  let(:service) { described_class.new(f) }
-
   describe "#to_plist" do
     it "returns valid plist" do
-      service.instance_eval do
-        run [opt_bin/"beanstalkd"]
+      f.class.service do
+        run opt_bin/"beanstalkd"
         run_type :immediate
         environment_variables PATH: std_service_path_env
         error_log_path var/"log/beanstalkd.error.log"
@@ -29,7 +27,7 @@ describe Homebrew::Service do
         keep_alive true
       end
 
-      plist = service.to_plist
+      plist = f.service.to_plist
       expect(plist).to include("<key>Label</key>")
       expect(plist).to include("<string>homebrew.mxcl.#{name}</string>")
       expect(plist).to include("<key>KeepAlive</key>")
@@ -48,12 +46,12 @@ describe Homebrew::Service do
     end
 
     it "returns valid partial plist" do
-      service.instance_eval do
-        run ["#{HOMEBREW_PREFIX}/bin/beanstalkd"]
+      f.class.service do
+        run bin/"beanstalkd"
         run_type :immediate
       end
 
-      plist = service.to_plist
+      plist = f.service.to_plist
       expect(plist).to include("<string>homebrew.mxcl.#{name}</string>")
       expect(plist).to include("<key>Label</key>")
       expect(plist).not_to include("<key>KeepAlive</key>")