From db8d488db418653d3a454dc2654f5a7d256ce379 Mon Sep 17 00:00:00 2001
From: apainintheneck <apainintheneck@gmail.com>
Date: Fri, 17 Mar 2023 23:24:37 -0700
Subject: [PATCH 1/7] service: add info to API json and load from api

As a part of serializing the hash, certain path
placeholders are used for the HOMEBREW_PREFIX and $HOME
directories. Beyond that certain elements need to be
turned back into strings like cron and sockets and symbols
need to be preserved as well.

The run command accepts either an arg or kwargs so it
has to be treated specially here.
---
 Library/Homebrew/formula.rb   |   3 +-
 Library/Homebrew/formulary.rb |  15 +++++
 Library/Homebrew/service.rb   | 105 +++++++++++++++++++++++++++++++---
 3 files changed, 115 insertions(+), 8 deletions(-)

diff --git a/Library/Homebrew/formula.rb b/Library/Homebrew/formula.rb
index bc3bb68d26..c71a854cc2 100644
--- a/Library/Homebrew/formula.rb
+++ b/Library/Homebrew/formula.rb
@@ -1043,7 +1043,7 @@ class Formula
   def service
     return unless service?
 
-    Homebrew::Service.new(self, &self.class.service)
+    @service ||= Homebrew::Service.new(self, &self.class.service)
   end
 
   # @private
@@ -2132,6 +2132,7 @@ class Formula
       "disabled"                 => disabled?,
       "disable_date"             => disable_date,
       "disable_reason"           => disable_reason,
+      "service"                  => service&.serialize,
       "tap_git_head"             => tap_git_head,
       "ruby_source_checksum"     => {},
     }
diff --git a/Library/Homebrew/formulary.rb b/Library/Homebrew/formulary.rb
index aa179fbcfa..0113ace173 100644
--- a/Library/Homebrew/formulary.rb
+++ b/Library/Homebrew/formulary.rb
@@ -263,6 +263,21 @@ module Formulary
         raise "Cannot build from source from abstract formula."
       end
 
+      if (service_hash = json_formula["service"])
+        service_hash = Homebrew::Service.deserialize(service_hash)
+        run_params = service_hash.delete("run")
+        service do
+          if run_params.is_a?(Hash)
+            run(**run_params)
+          else
+            run run_params
+          end
+          service_hash.each do |key, arg|
+            public_send(key, arg)
+          end
+        end
+      end
+
       @caveats_string = json_formula["caveats"]
       def caveats
         self.class.instance_variable_get(:@caveats_string)
diff --git a/Library/Homebrew/service.rb b/Library/Homebrew/service.rb
index 4725a8acb0..7f149b3a1f 100644
--- a/Library/Homebrew/service.rb
+++ b/Library/Homebrew/service.rb
@@ -45,6 +45,9 @@ module Homebrew
       ).returns(T.nilable(Array))
     }
     def run(command = nil, macos: nil, linux: nil)
+      # Save parameters for serialization
+      @run_params ||= command || { macos: macos, linux: linux }.compact
+
       command ||= on_system_conditional(macos: macos, linux: linux)
       case T.unsafe(command)
       when nil
@@ -156,7 +159,7 @@ module Homebrew
     # @return [Boolean]
     sig { returns(T::Boolean) }
     def requires_root?
-      instance_eval(&@service_block)
+      eval_service_block
       @require_root.present? && @require_root == true
     end
 
@@ -192,7 +195,7 @@ module Homebrew
     # @return [Boolean]
     sig { returns(T::Boolean) }
     def keep_alive?
-      instance_eval(&@service_block)
+      eval_service_block
       @keep_alive.present? && @keep_alive[:always] != false
     end
 
@@ -320,7 +323,7 @@ module Homebrew
       parsed
     end
 
-    sig { params(variables: T::Hash[String, String]).returns(T.nilable(T::Hash[String, String])) }
+    sig { params(variables: T::Hash[Symbol, String]).returns(T.nilable(T::Hash[Symbol, String])) }
     def environment_variables(variables = {})
       case T.unsafe(variables)
       when Hash
@@ -351,7 +354,7 @@ module Homebrew
 
     sig { returns(T.nilable(T::Array[String])) }
     def command
-      instance_eval(&@service_block)
+      eval_service_block
       @run&.map(&:to_s)
     end
 
@@ -359,7 +362,7 @@ module Homebrew
     # @return [String]
     sig { returns(String) }
     def manual_command
-      instance_eval(&@service_block)
+      eval_service_block
       vars = @environment_variables.except(:PATH)
                                    .map { |k, v| "#{k}=\"#{v}\"" }
 
@@ -372,7 +375,7 @@ module Homebrew
     # @return [Boolean]
     sig { returns(T::Boolean) }
     def timed?
-      instance_eval(&@service_block)
+      eval_service_block
       @run_type == RUN_TYPE_CRON || @run_type == RUN_TYPE_INTERVAL
     end
 
@@ -484,7 +487,7 @@ module Homebrew
         Unit=#{@formula.service_name}
       EOS
 
-      instance_eval(&@service_block)
+      eval_service_block
       options = []
       options << "Persistent=true" if @run_type == RUN_TYPE_CRON
       options << "OnUnitActiveSec=#{@interval}" if @run_type == RUN_TYPE_INTERVAL
@@ -497,5 +500,93 @@ module Homebrew
 
       timer + options.join("\n")
     end
+
+    # Only evaluate the service block once.
+    sig { void }
+    def eval_service_block
+      return if @eval_service_block
+
+      instance_eval(&@service_block)
+      @eval_service_block = true
+    end
+
+    # Recursively prepare the service hash for inclusion in the formula API JSON.
+    # - Replace each Symbol with a String prefixed by ":"
+    # - Replace the local HOMEBREW_PREFIX with "$HOMEBREW_PREFIX"
+    # - Replace the local home directory with "$HOME"
+    def serialize(elem = to_h)
+      case elem
+      when String, Pathname
+        elem.to_s.gsub(HOMEBREW_PREFIX, HOMEBREW_PREFIX_PLACEHOLDER)
+            .gsub(Dir.home, "$HOME")
+      when Symbol
+        elem.inspect
+      when Array
+        elem.map { |value| serialize(value) }
+      when Hash
+        elem.to_h do |key, value|
+          key = key.inspect if key.is_a?(Symbol)
+          [key, serialize(value)]
+        end
+      else
+        elem
+      end
+    end
+
+    # Recursively turn the service API hash values back into what is expected by the formula DSL.
+    # - Replace each String prefixed with ":" with a Symbol
+    # - Replace "$HOMEBREW_PREFIX" with the local HOMEBREW_PREFIX environment variable
+    # - Replace "$HOME" with the local home directory
+    def self.deserialize(elem)
+      case elem
+      when String
+        return T.must(elem[1..]).to_sym if elem.start_with?(":")
+
+        elem.gsub(HOMEBREW_PREFIX_PLACEHOLDER, HOMEBREW_PREFIX)
+            .gsub("$HOME", Dir.home)
+      when Array
+        elem.map { |value| deserialize(value) }
+      when Hash
+        elem.to_h do |key, value|
+          key = key[1..].to_sym if key.start_with?(":")
+          [key, deserialize(value)]
+        end
+      else
+        elem
+      end
+    end
+
+    sig { returns(Hash) }
+    def to_h
+      eval_service_block
+
+      cron_string = if @cron.present?
+        [:Minute, :Hour, :Day, :Month, :Weekday]
+          .map { |key| @cron[key].to_s }
+          .join(" ")
+      end
+
+      sockets_string = "#{@sockets[:type]}://#{@sockets[:host]}:#{@sockets[:port]}" if @sockets.present?
+
+      {
+        "run"                   => @run_params,
+        "run_type"              => @run_type,
+        "interval"              => @interval,
+        "cron"                  => cron_string,
+        "keep_alive"            => @keep_alive,
+        "launch_only_once"      => @launch_only_once,
+        "require_root"          => @require_root,
+        "environment_variables" => @environment_variables.presence,
+        "working_dir"           => @working_dir,
+        "root_dir"              => @root_dir,
+        "input_path"            => @input_path,
+        "log_path"              => @log_path,
+        "error_log_path"        => @error_log_path,
+        "restart_delay"         => @restart_delay,
+        "process_type"          => @process_type,
+        "macos_legacy_timers"   => @macos_legacy_timers,
+        "sockets"               => sockets_string,
+      }.compact
+    end
   end
 end

From 501730df5d9857f4d711f472725b22c433b14f12 Mon Sep 17 00:00:00 2001
From: apainintheneck <apainintheneck@gmail.com>
Date: Sat, 18 Mar 2023 13:23:30 -0700
Subject: [PATCH 2/7] Add service serialization specs

---
 Library/Homebrew/test/service_spec.rb | 77 +++++++++++++++++++++++++++
 1 file changed, 77 insertions(+)

diff --git a/Library/Homebrew/test/service_spec.rb b/Library/Homebrew/test/service_spec.rb
index 04934da624..f552e2c3f9 100644
--- a/Library/Homebrew/test/service_spec.rb
+++ b/Library/Homebrew/test/service_spec.rb
@@ -913,4 +913,81 @@ describe Homebrew::Service do
       expect(command).to eq(["#{HOMEBREW_PREFIX}/opt/#{name}/bin/beanstalkd", "test", "macos"])
     end
   end
+
+  describe "#serialize" do
+    context "with a single run command" do
+      let(:serialized_hash) do
+        {
+          "environment_variables" => {
+            ":PATH" => "$HOMEBREW_PREFIX/bin:$HOMEBREW_PREFIX/sbin:/usr/bin:/bin:/usr/sbin:/sbin",
+          },
+          "run"                   => ["$HOMEBREW_PREFIX/opt/formula_name/bin/beanstalkd", "test"],
+          "run_type"              => ":immediate",
+          "working_dir"           => "$HOME",
+        }
+      end
+
+      it "replaces local paths with placeholders" do
+        f = stub_formula do
+          service do
+            run [opt_bin/"beanstalkd", "test"]
+            environment_variables PATH: std_service_path_env
+            working_dir Dir.home
+          end
+        end
+
+        expect(f.service.serialize).to eq(serialized_hash)
+      end
+    end
+
+    context "with OS specific run commands" do
+      let(:serialized_hash) do
+        {
+          "run"      => {
+            ":macos" => ["$HOMEBREW_PREFIX/opt/formula_name/bin/beanstalkd", "macos"],
+            ":linux" => ["$HOMEBREW_PREFIX/opt/formula_name/bin/beanstalkd", "linux"],
+          },
+          "run_type" => ":immediate",
+        }
+      end
+
+      it "replaces local paths with placeholders" do
+        f = stub_formula do
+          service do
+            run macos: [opt_bin/"beanstalkd", "macos"], linux: [opt_bin/"beanstalkd", "linux"]
+          end
+        end
+
+        expect(f.service.serialize).to eq(serialized_hash)
+      end
+    end
+  end
+
+  describe ".deserialize" do
+    let(:serialized_hash) do
+      {
+        "environment_variables" => {
+          ":PATH" => "$HOMEBREW_PREFIX/bin:$HOMEBREW_PREFIX/sbin:/usr/bin:/bin:/usr/sbin:/sbin",
+        },
+        "run"                   => ["$HOMEBREW_PREFIX/opt/formula_name/bin/beanstalkd", "test"],
+        "run_type"              => ":immediate",
+        "working_dir"           => "$HOME",
+      }
+    end
+
+    let(:deserialized_hash) do
+      {
+        "environment_variables" => {
+          PATH: "#{HOMEBREW_PREFIX}/bin:#{HOMEBREW_PREFIX}/sbin:/usr/bin:/bin:/usr/sbin:/sbin",
+        },
+        "run"                   => ["#{HOMEBREW_PREFIX}/opt/formula_name/bin/beanstalkd", "test"],
+        "run_type"              => :immediate,
+        "working_dir"           => Dir.home,
+      }
+    end
+
+    it "replaces placeholders with local paths" do
+      expect(described_class.deserialize(serialized_hash)).to eq(deserialized_hash)
+    end
+  end
 end

From d42e9b40d5b5e03e7bd292c4cf977f7ed9a237b0 Mon Sep 17 00:00:00 2001
From: apainintheneck <apainintheneck@gmail.com>
Date: Sat, 18 Mar 2023 15:18:29 -0700
Subject: [PATCH 3/7] formulary: add test for loading service blocks from API

---
 Library/Homebrew/test/formulary_spec.rb | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/Library/Homebrew/test/formulary_spec.rb b/Library/Homebrew/test/formulary_spec.rb
index ef20f3229a..b20a00b237 100644
--- a/Library/Homebrew/test/formulary_spec.rb
+++ b/Library/Homebrew/test/formulary_spec.rb
@@ -272,6 +272,11 @@ describe Formulary do
             "conflicts_with_reasons"   => ["it does"],
             "link_overwrite"           => ["bin/abc"],
             "caveats"                  => "example caveat string",
+            "service"                  => {
+              "run"         => ["$HOMEBREW_PREFIX/opt/formula_name/bin/beanstalkd", "test"],
+              "run_type"    => :immediate,
+              "working_dir" => "$HOME",
+            },
           }.merge(extra_items),
         }
       end
@@ -354,6 +359,11 @@ describe Formulary do
 
         expect(formula.caveats).to eq "example caveat string"
 
+        expect(formula).to be_a_service
+        expect(formula.service.command).to eq(["#{HOMEBREW_PREFIX}/opt/formula_name/bin/beanstalkd", "test"])
+        expect(formula.service.run_type).to eq(:immediate)
+        expect(formula.service.working_dir).to eq(Dir.home)
+
         expect do
           formula.install
         end.to raise_error("Cannot build from source from abstract formula.")

From 38146893c3966d0ad1a359f866df4dbf49b9e176 Mon Sep 17 00:00:00 2001
From: apainintheneck <apainintheneck@gmail.com>
Date: Tue, 21 Mar 2023 19:05:41 -0700
Subject: [PATCH 4/7] api_hashable: Make API path subs generic

This turns the ability to replace common paths with placeholders
into a mixin that can be used with both Casks and Formulae.

The idea here is to make formula hash generation more consistent.
---
 Library/Homebrew/cask/cask.rb                 | 36 ++-----------------
 Library/Homebrew/cask/cask_loader.rb          |  4 +--
 .../Homebrew/dev-cmd/generate-formula-api.rb  |  1 +
 Library/Homebrew/extend/api_hashable.rb       | 34 ++++++++++++++++++
 Library/Homebrew/formula.rb                   |  2 ++
 Library/Homebrew/global.rb                    |  2 ++
 Library/Homebrew/test/cask/cask_spec.rb       |  2 ++
 7 files changed, 45 insertions(+), 36 deletions(-)
 create mode 100644 Library/Homebrew/extend/api_hashable.rb

diff --git a/Library/Homebrew/cask/cask.rb b/Library/Homebrew/cask/cask.rb
index 04f68cda0c..9b497a4082 100644
--- a/Library/Homebrew/cask/cask.rb
+++ b/Library/Homebrew/cask/cask.rb
@@ -6,6 +6,7 @@ require "cask/config"
 require "cask/dsl"
 require "cask/metadata"
 require "utils/bottles"
+require "extend/api_hashable"
 
 module Cask
   # An instance of a cask.
@@ -16,11 +17,9 @@ module Cask
 
     extend Forwardable
     extend Predicable
+    extend APIHashable
     include Metadata
 
-    # Needs a leading slash to avoid `File.expand.path` complaining about non-absolute home.
-    HOME_PLACEHOLDER = "/$HOME"
-    HOMEBREW_PREFIX_PLACEHOLDER = "$HOMEBREW_PREFIX"
     APPDIR_PLACEHOLDER = "$APPDIR"
 
     # TODO: can be removed when API JSON is regenerated with HOMEBREW_PREFIX_PLACEHOLDER.
@@ -31,37 +30,6 @@ module Cask
 
     attr_predicate :loaded_from_api?
 
-    class << self
-      def generating_hash!
-        return if generating_hash?
-
-        # Apply monkeypatches for API generation
-        @old_homebrew_prefix = HOMEBREW_PREFIX
-        @old_home = Dir.home
-        Object.send(:remove_const, :HOMEBREW_PREFIX)
-        Object.const_set(:HOMEBREW_PREFIX, Pathname(HOMEBREW_PREFIX_PLACEHOLDER))
-        ENV["HOME"] = HOME_PLACEHOLDER
-
-        @generating_hash = true
-      end
-
-      def generated_hash!
-        return unless generating_hash?
-
-        # Revert monkeypatches for API generation
-        Object.send(:remove_const, :HOMEBREW_PREFIX)
-        Object.const_set(:HOMEBREW_PREFIX, @old_homebrew_prefix)
-        ENV["HOME"] = @old_home
-
-        @generating_hash = false
-      end
-
-      def generating_hash?
-        @generating_hash ||= false
-        @generating_hash == true
-      end
-    end
-
     def self.all
       # TODO: ideally avoid using ARGV by moving to e.g. CLI::Parser
       if ARGV.exclude?("--eval-all") && !Homebrew::EnvConfig.eval_all?
diff --git a/Library/Homebrew/cask/cask_loader.rb b/Library/Homebrew/cask/cask_loader.rb
index 0fa41924df..3f884a630b 100644
--- a/Library/Homebrew/cask/cask_loader.rb
+++ b/Library/Homebrew/cask/cask_loader.rb
@@ -329,8 +329,8 @@ module Cask
         # TODO: HOMEBREW_OLD_PREFIX_PLACEHOLDER can be removed when API JSON is
         #       regenerated with HOMEBREW_PREFIX_PLACEHOLDER.
         string.to_s
-              .gsub(Cask::HOME_PLACEHOLDER, Dir.home)
-              .gsub(Cask::HOMEBREW_PREFIX_PLACEHOLDER, HOMEBREW_PREFIX)
+              .gsub(HOMEBREW_HOME_PLACEHOLDER, Dir.home)
+              .gsub(HOMEBREW_PREFIX_PLACEHOLDER, HOMEBREW_PREFIX)
               .gsub(Cask::APPDIR_PLACEHOLDER, appdir)
               .gsub(Cask::HOMEBREW_OLD_PREFIX_PLACEHOLDER, HOMEBREW_PREFIX)
       end
diff --git a/Library/Homebrew/dev-cmd/generate-formula-api.rb b/Library/Homebrew/dev-cmd/generate-formula-api.rb
index c47c0f4571..fb05cb187c 100644
--- a/Library/Homebrew/dev-cmd/generate-formula-api.rb
+++ b/Library/Homebrew/dev-cmd/generate-formula-api.rb
@@ -50,6 +50,7 @@ module Homebrew
     FileUtils.mkdir_p directories
 
     Formulary.enable_factory_cache!
+    Formula.generating_hash!
 
     tap.formula_names.each do |name|
       formula = Formulary.factory(name)
diff --git a/Library/Homebrew/extend/api_hashable.rb b/Library/Homebrew/extend/api_hashable.rb
new file mode 100644
index 0000000000..0527a94938
--- /dev/null
+++ b/Library/Homebrew/extend/api_hashable.rb
@@ -0,0 +1,34 @@
+# typed: true
+# frozen_string_literal: true
+
+# Used to substitute common paths with generic placeholders when generating JSON for the API.
+module APIHashable
+  def generating_hash!
+    return if generating_hash?
+
+    # Apply monkeypatches for API generation
+    @old_homebrew_prefix = HOMEBREW_PREFIX
+    @old_home = Dir.home
+    Object.send(:remove_const, :HOMEBREW_PREFIX)
+    Object.const_set(:HOMEBREW_PREFIX, Pathname.new(HOMEBREW_PREFIX_PLACEHOLDER))
+    ENV["HOME"] = HOMEBREW_HOME_PLACEHOLDER
+
+    @generating_hash = true
+  end
+
+  def generated_hash!
+    return unless generating_hash?
+
+    # Revert monkeypatches for API generation
+    Object.send(:remove_const, :HOMEBREW_PREFIX)
+    Object.const_set(:HOMEBREW_PREFIX, @old_homebrew_prefix)
+    ENV["HOME"] = @old_home
+
+    @generating_hash = false
+  end
+
+  def generating_hash?
+    @generating_hash ||= false
+    @generating_hash == true
+  end
+end
diff --git a/Library/Homebrew/formula.rb b/Library/Homebrew/formula.rb
index c71a854cc2..19f2bde8e6 100644
--- a/Library/Homebrew/formula.rb
+++ b/Library/Homebrew/formula.rb
@@ -30,6 +30,7 @@ require "find"
 require "utils/spdx"
 require "extend/on_system"
 require "api"
+require "extend/api_hashable"
 
 # A formula provides instructions and metadata for Homebrew to install a piece
 # of software. Every Homebrew formula is a {Formula}.
@@ -69,6 +70,7 @@ class Formula
   extend Forwardable
   extend Cachable
   extend Predicable
+  extend APIHashable
 
   # The name of this {Formula}.
   # e.g. `this-formula`
diff --git a/Library/Homebrew/global.rb b/Library/Homebrew/global.rb
index de6e01e5e4..1ed2ee7d21 100644
--- a/Library/Homebrew/global.rb
+++ b/Library/Homebrew/global.rb
@@ -58,6 +58,8 @@ HOMEBREW_MACOS_ARM_DEFAULT_REPOSITORY = ENV.fetch("HOMEBREW_MACOS_ARM_DEFAULT_RE
 HOMEBREW_LINUX_DEFAULT_PREFIX = ENV.fetch("HOMEBREW_LINUX_DEFAULT_PREFIX").freeze
 HOMEBREW_LINUX_DEFAULT_REPOSITORY = ENV.fetch("HOMEBREW_LINUX_DEFAULT_REPOSITORY").freeze
 HOMEBREW_PREFIX_PLACEHOLDER = "$HOMEBREW_PREFIX"
+# Needs a leading slash to avoid `File.expand.path` complaining about non-absolute home.
+HOMEBREW_HOME_PLACEHOLDER = "/$HOME"
 
 HOMEBREW_MACOS_NEWEST_UNSUPPORTED = ENV.fetch("HOMEBREW_MACOS_NEWEST_UNSUPPORTED").freeze
 HOMEBREW_MACOS_OLDEST_SUPPORTED = ENV.fetch("HOMEBREW_MACOS_OLDEST_SUPPORTED").freeze
diff --git a/Library/Homebrew/test/cask/cask_spec.rb b/Library/Homebrew/test/cask/cask_spec.rb
index ddc581c730..065d8fe6d0 100644
--- a/Library/Homebrew/test/cask/cask_spec.rb
+++ b/Library/Homebrew/test/cask/cask_spec.rb
@@ -337,6 +337,8 @@ describe Cask::Cask, :cask do
       expect(JSON.pretty_generate(h["variations"])).to eq expected_sha256_variations.strip
     end
 
+    # @note The calls to `APIHashable.generating_hash!` and `APIHashable.generated_hash!`
+    #   are not idempotent so they can only be used in one test.
     it "returns the correct hash placeholders" do
       described_class.generating_hash!
       expect(described_class).to be_generating_hash

From bc85857e1341eef2e105cbacd3e5f1e4eaaf47a0 Mon Sep 17 00:00:00 2001
From: apainintheneck <apainintheneck@gmail.com>
Date: Tue, 21 Mar 2023 21:53:52 -0700
Subject: [PATCH 5/7] service: make serialization non-recursive

This helps with type annotations and makes it easier to
reason about the code as well.
---
 Library/Homebrew/formulary.rb |   2 +-
 Library/Homebrew/service.rb   | 136 ++++++++++++++++++----------------
 2 files changed, 73 insertions(+), 65 deletions(-)

diff --git a/Library/Homebrew/formulary.rb b/Library/Homebrew/formulary.rb
index 0113ace173..b318dcf9d4 100644
--- a/Library/Homebrew/formulary.rb
+++ b/Library/Homebrew/formulary.rb
@@ -265,7 +265,7 @@ module Formulary
 
       if (service_hash = json_formula["service"])
         service_hash = Homebrew::Service.deserialize(service_hash)
-        run_params = service_hash.delete("run")
+        run_params = service_hash.delete(:run)
         service do
           if run_params.is_a?(Hash)
             run(**run_params)
diff --git a/Library/Homebrew/service.rb b/Library/Homebrew/service.rb
index 7f149b3a1f..d676203d29 100644
--- a/Library/Homebrew/service.rb
+++ b/Library/Homebrew/service.rb
@@ -510,54 +510,9 @@ module Homebrew
       @eval_service_block = true
     end
 
-    # Recursively prepare the service hash for inclusion in the formula API JSON.
-    # - Replace each Symbol with a String prefixed by ":"
-    # - Replace the local HOMEBREW_PREFIX with "$HOMEBREW_PREFIX"
-    # - Replace the local home directory with "$HOME"
-    def serialize(elem = to_h)
-      case elem
-      when String, Pathname
-        elem.to_s.gsub(HOMEBREW_PREFIX, HOMEBREW_PREFIX_PLACEHOLDER)
-            .gsub(Dir.home, "$HOME")
-      when Symbol
-        elem.inspect
-      when Array
-        elem.map { |value| serialize(value) }
-      when Hash
-        elem.to_h do |key, value|
-          key = key.inspect if key.is_a?(Symbol)
-          [key, serialize(value)]
-        end
-      else
-        elem
-      end
-    end
-
-    # Recursively turn the service API hash values back into what is expected by the formula DSL.
-    # - Replace each String prefixed with ":" with a Symbol
-    # - Replace "$HOMEBREW_PREFIX" with the local HOMEBREW_PREFIX environment variable
-    # - Replace "$HOME" with the local home directory
-    def self.deserialize(elem)
-      case elem
-      when String
-        return T.must(elem[1..]).to_sym if elem.start_with?(":")
-
-        elem.gsub(HOMEBREW_PREFIX_PLACEHOLDER, HOMEBREW_PREFIX)
-            .gsub("$HOME", Dir.home)
-      when Array
-        elem.map { |value| deserialize(value) }
-      when Hash
-        elem.to_h do |key, value|
-          key = key[1..].to_sym if key.start_with?(":")
-          [key, deserialize(value)]
-        end
-      else
-        elem
-      end
-    end
-
+    # Prepare the service hash for inclusion in the formula API JSON.
     sig { returns(Hash) }
-    def to_h
+    def serialize
       eval_service_block
 
       cron_string = if @cron.present?
@@ -569,24 +524,77 @@ module Homebrew
       sockets_string = "#{@sockets[:type]}://#{@sockets[:host]}:#{@sockets[:port]}" if @sockets.present?
 
       {
-        "run"                   => @run_params,
-        "run_type"              => @run_type,
-        "interval"              => @interval,
-        "cron"                  => cron_string,
-        "keep_alive"            => @keep_alive,
-        "launch_only_once"      => @launch_only_once,
-        "require_root"          => @require_root,
-        "environment_variables" => @environment_variables.presence,
-        "working_dir"           => @working_dir,
-        "root_dir"              => @root_dir,
-        "input_path"            => @input_path,
-        "log_path"              => @log_path,
-        "error_log_path"        => @error_log_path,
-        "restart_delay"         => @restart_delay,
-        "process_type"          => @process_type,
-        "macos_legacy_timers"   => @macos_legacy_timers,
-        "sockets"               => sockets_string,
+        run:                   @run_params,
+        run_type:              @run_type,
+        interval:              @interval,
+        cron:                  cron_string,
+        keep_alive:            @keep_alive,
+        launch_only_once:      @launch_only_once,
+        require_root:          @require_root,
+        environment_variables: @environment_variables.presence,
+        working_dir:           @working_dir,
+        root_dir:              @root_dir,
+        input_path:            @input_path,
+        log_path:              @log_path,
+        error_log_path:        @error_log_path,
+        restart_delay:         @restart_delay,
+        process_type:          @process_type,
+        macos_legacy_timers:   @macos_legacy_timers,
+        sockets:               sockets_string,
       }.compact
     end
+
+    # Turn the service API hash values back into what is expected by the formula DSL.
+    sig { params(api_hash: Hash).returns(Hash) }
+    def self.deserialize(api_hash)
+      hash = {}
+      hash[:run] =
+        case api_hash["run"]
+        when Hash
+          api_hash["run"].to_h do |key, array|
+            [
+              key.to_sym,
+              array.map { |value| replace_placeholders(value) },
+            ]
+          end
+        when Array
+          api_hash["run"].map { |value| replace_placeholders(value) }
+        end
+
+      hash[:keep_alive] = api_hash["keep_alive"].transform_keys(&:to_sym) if api_hash.key?("keep_alive")
+
+      if api_hash.key?("environment_variables")
+        hash[:environment_variables] = api_hash["environment_variables"].to_h do |key, value|
+          [key.to_sym, replace_placeholders(value)]
+        end
+      end
+
+      %w[run_type process_type].each do |key|
+        next unless (value = api_hash[key])
+
+        hash[key.to_sym] = value.to_sym
+      end
+
+      %w[working_dir root_dir input_path log_path error_log_path].each do |key|
+        next unless (value = api_hash[key])
+
+        hash[key.to_sym] = replace_placeholders(value)
+      end
+
+      %w[interval cron launch_only_once require_root restart_delay macos_legacy_timers sockets].each do |key|
+        next if (value = api_hash[key]).nil?
+
+        hash[key.to_sym] = value
+      end
+
+      hash
+    end
+
+    # Replace API path placeholders with local paths.
+    sig { params(string: String).returns(String) }
+    def self.replace_placeholders(string)
+      string.gsub(HOMEBREW_PREFIX_PLACEHOLDER, HOMEBREW_PREFIX)
+            .gsub(HOMEBREW_HOME_PLACEHOLDER, Dir.home)
+    end
   end
 end

From e83a2562bba6a36b32403d2189654ea0fb60be5b Mon Sep 17 00:00:00 2001
From: apainintheneck <apainintheneck@gmail.com>
Date: Tue, 21 Mar 2023 21:55:47 -0700
Subject: [PATCH 6/7] Update service and formulary specs

---
 Library/Homebrew/test/formulary_spec.rb |  4 +-
 Library/Homebrew/test/service_spec.rb   | 80 ++++++++++---------------
 2 files changed, 34 insertions(+), 50 deletions(-)

diff --git a/Library/Homebrew/test/formulary_spec.rb b/Library/Homebrew/test/formulary_spec.rb
index b20a00b237..85cf0c6ae0 100644
--- a/Library/Homebrew/test/formulary_spec.rb
+++ b/Library/Homebrew/test/formulary_spec.rb
@@ -274,8 +274,8 @@ describe Formulary do
             "caveats"                  => "example caveat string",
             "service"                  => {
               "run"         => ["$HOMEBREW_PREFIX/opt/formula_name/bin/beanstalkd", "test"],
-              "run_type"    => :immediate,
-              "working_dir" => "$HOME",
+              "run_type"    => "immediate",
+              "working_dir" => "/$HOME",
             },
           }.merge(extra_items),
         }
diff --git a/Library/Homebrew/test/service_spec.rb b/Library/Homebrew/test/service_spec.rb
index f552e2c3f9..4f255d8aa8 100644
--- a/Library/Homebrew/test/service_spec.rb
+++ b/Library/Homebrew/test/service_spec.rb
@@ -915,51 +915,33 @@ describe Homebrew::Service do
   end
 
   describe "#serialize" do
-    context "with a single run command" do
-      let(:serialized_hash) do
-        {
-          "environment_variables" => {
-            ":PATH" => "$HOMEBREW_PREFIX/bin:$HOMEBREW_PREFIX/sbin:/usr/bin:/bin:/usr/sbin:/sbin",
-          },
-          "run"                   => ["$HOMEBREW_PREFIX/opt/formula_name/bin/beanstalkd", "test"],
-          "run_type"              => ":immediate",
-          "working_dir"           => "$HOME",
-        }
-      end
-
-      it "replaces local paths with placeholders" do
-        f = stub_formula do
-          service do
-            run [opt_bin/"beanstalkd", "test"]
-            environment_variables PATH: std_service_path_env
-            working_dir Dir.home
-          end
-        end
-
-        expect(f.service.serialize).to eq(serialized_hash)
-      end
+    let(:serialized_hash) do
+      {
+        environment_variables: {
+          PATH: "$HOMEBREW_PREFIX/bin:$HOMEBREW_PREFIX/sbin:/usr/bin:/bin:/usr/sbin:/sbin",
+        },
+        run:                   [Pathname("$HOMEBREW_PREFIX/opt/formula_name/bin/beanstalkd"), "test"],
+        run_type:              :immediate,
+        working_dir:           "/$HOME",
+        cron:                  "0 0 * * 0",
+        sockets:               "tcp://0.0.0.0:80",
+      }
     end
 
-    context "with OS specific run commands" do
-      let(:serialized_hash) do
-        {
-          "run"      => {
-            ":macos" => ["$HOMEBREW_PREFIX/opt/formula_name/bin/beanstalkd", "macos"],
-            ":linux" => ["$HOMEBREW_PREFIX/opt/formula_name/bin/beanstalkd", "linux"],
-          },
-          "run_type" => ":immediate",
-        }
-      end
-
-      it "replaces local paths with placeholders" do
-        f = stub_formula do
-          service do
-            run macos: [opt_bin/"beanstalkd", "macos"], linux: [opt_bin/"beanstalkd", "linux"]
-          end
+    it "replaces local paths with placeholders" do
+      f = stub_formula do
+        service do
+          run [opt_bin/"beanstalkd", "test"]
+          environment_variables PATH: std_service_path_env
+          working_dir Dir.home
+          cron "@weekly"
+          sockets "tcp://0.0.0.0:80"
         end
-
-        expect(f.service.serialize).to eq(serialized_hash)
       end
+
+      Formula.generating_hash!
+      expect(f.service.serialize).to eq(serialized_hash)
+      Formula.generated_hash!
     end
   end
 
@@ -967,22 +949,24 @@ describe Homebrew::Service do
     let(:serialized_hash) do
       {
         "environment_variables" => {
-          ":PATH" => "$HOMEBREW_PREFIX/bin:$HOMEBREW_PREFIX/sbin:/usr/bin:/bin:/usr/sbin:/sbin",
+          "PATH" => "$HOMEBREW_PREFIX/bin:$HOMEBREW_PREFIX/sbin:/usr/bin:/bin:/usr/sbin:/sbin",
         },
         "run"                   => ["$HOMEBREW_PREFIX/opt/formula_name/bin/beanstalkd", "test"],
-        "run_type"              => ":immediate",
-        "working_dir"           => "$HOME",
+        "run_type"              => "immediate",
+        "working_dir"           => HOMEBREW_HOME_PLACEHOLDER,
+        "keep_alive"            => { "successful_exit" => false },
       }
     end
 
     let(:deserialized_hash) do
       {
-        "environment_variables" => {
+        environment_variables: {
           PATH: "#{HOMEBREW_PREFIX}/bin:#{HOMEBREW_PREFIX}/sbin:/usr/bin:/bin:/usr/sbin:/sbin",
         },
-        "run"                   => ["#{HOMEBREW_PREFIX}/opt/formula_name/bin/beanstalkd", "test"],
-        "run_type"              => :immediate,
-        "working_dir"           => Dir.home,
+        run:                   ["#{HOMEBREW_PREFIX}/opt/formula_name/bin/beanstalkd", "test"],
+        run_type:              :immediate,
+        working_dir:           Dir.home,
+        keep_alive:            { successful_exit: false },
       }
     end
 

From 801ee5e4744ba4f046e01d442ffd749af2d163a5 Mon Sep 17 00:00:00 2001
From: apainintheneck <apainintheneck@gmail.com>
Date: Wed, 22 Mar 2023 19:43:49 -0700
Subject: [PATCH 7/7] Address feedback

- style nits
- better comments for tests that are not idempotent
- moved appdir placeholder constant to global.rb
---
 Library/Homebrew/cask/cask.rb           | 2 --
 Library/Homebrew/cask/cask_loader.rb    | 2 +-
 Library/Homebrew/cask/dsl.rb            | 2 +-
 Library/Homebrew/global.rb              | 1 +
 Library/Homebrew/service.rb             | 7 ++++---
 Library/Homebrew/test/cask/cask_spec.rb | 2 +-
 Library/Homebrew/test/service_spec.rb   | 2 ++
 7 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/Library/Homebrew/cask/cask.rb b/Library/Homebrew/cask/cask.rb
index 9b497a4082..e654f3260d 100644
--- a/Library/Homebrew/cask/cask.rb
+++ b/Library/Homebrew/cask/cask.rb
@@ -20,8 +20,6 @@ module Cask
     extend APIHashable
     include Metadata
 
-    APPDIR_PLACEHOLDER = "$APPDIR"
-
     # TODO: can be removed when API JSON is regenerated with HOMEBREW_PREFIX_PLACEHOLDER.
     HOMEBREW_OLD_PREFIX_PLACEHOLDER = "$(brew --prefix)"
 
diff --git a/Library/Homebrew/cask/cask_loader.rb b/Library/Homebrew/cask/cask_loader.rb
index 3f884a630b..a47a6464a3 100644
--- a/Library/Homebrew/cask/cask_loader.rb
+++ b/Library/Homebrew/cask/cask_loader.rb
@@ -331,7 +331,7 @@ module Cask
         string.to_s
               .gsub(HOMEBREW_HOME_PLACEHOLDER, Dir.home)
               .gsub(HOMEBREW_PREFIX_PLACEHOLDER, HOMEBREW_PREFIX)
-              .gsub(Cask::APPDIR_PLACEHOLDER, appdir)
+              .gsub(HOMEBREW_CASK_APPDIR_PLACEHOLDER, appdir)
               .gsub(Cask::HOMEBREW_OLD_PREFIX_PLACEHOLDER, HOMEBREW_PREFIX)
       end
 
diff --git a/Library/Homebrew/cask/dsl.rb b/Library/Homebrew/cask/dsl.rb
index 461b87af5b..7976100525 100644
--- a/Library/Homebrew/cask/dsl.rb
+++ b/Library/Homebrew/cask/dsl.rb
@@ -375,7 +375,7 @@ module Cask
 
     # @api public
     def appdir
-      return Cask::APPDIR_PLACEHOLDER if Cask.generating_hash?
+      return HOMEBREW_CASK_APPDIR_PLACEHOLDER if Cask.generating_hash?
 
       cask.config.appdir
     end
diff --git a/Library/Homebrew/global.rb b/Library/Homebrew/global.rb
index 1ed2ee7d21..3c3cecdb2d 100644
--- a/Library/Homebrew/global.rb
+++ b/Library/Homebrew/global.rb
@@ -60,6 +60,7 @@ HOMEBREW_LINUX_DEFAULT_REPOSITORY = ENV.fetch("HOMEBREW_LINUX_DEFAULT_REPOSITORY
 HOMEBREW_PREFIX_PLACEHOLDER = "$HOMEBREW_PREFIX"
 # Needs a leading slash to avoid `File.expand.path` complaining about non-absolute home.
 HOMEBREW_HOME_PLACEHOLDER = "/$HOME"
+HOMEBREW_CASK_APPDIR_PLACEHOLDER = "$APPDIR"
 
 HOMEBREW_MACOS_NEWEST_UNSUPPORTED = ENV.fetch("HOMEBREW_MACOS_NEWEST_UNSUPPORTED").freeze
 HOMEBREW_MACOS_OLDEST_SUPPORTED = ENV.fetch("HOMEBREW_MACOS_OLDEST_SUPPORTED").freeze
diff --git a/Library/Homebrew/service.rb b/Library/Homebrew/service.rb
index d676203d29..2e4aefe46b 100644
--- a/Library/Homebrew/service.rb
+++ b/Library/Homebrew/service.rb
@@ -46,7 +46,8 @@ module Homebrew
     }
     def run(command = nil, macos: nil, linux: nil)
       # Save parameters for serialization
-      @run_params ||= command || { macos: macos, linux: linux }.compact
+      @run_params ||= command
+      @run_params ||= { macos: macos, linux: linux }.compact
 
       command ||= on_system_conditional(macos: macos, linux: linux)
       case T.unsafe(command)
@@ -554,11 +555,11 @@ module Homebrew
           api_hash["run"].to_h do |key, array|
             [
               key.to_sym,
-              array.map { |value| replace_placeholders(value) },
+              array.map(&method(:replace_placeholders)),
             ]
           end
         when Array
-          api_hash["run"].map { |value| replace_placeholders(value) }
+          api_hash["run"].map(&method(:replace_placeholders))
         end
 
       hash[:keep_alive] = api_hash["keep_alive"].transform_keys(&:to_sym) if api_hash.key?("keep_alive")
diff --git a/Library/Homebrew/test/cask/cask_spec.rb b/Library/Homebrew/test/cask/cask_spec.rb
index 065d8fe6d0..f9dea17485 100644
--- a/Library/Homebrew/test/cask/cask_spec.rb
+++ b/Library/Homebrew/test/cask/cask_spec.rb
@@ -337,7 +337,7 @@ describe Cask::Cask, :cask do
       expect(JSON.pretty_generate(h["variations"])).to eq expected_sha256_variations.strip
     end
 
-    # @note The calls to `APIHashable.generating_hash!` and `APIHashable.generated_hash!`
+    # @note The calls to `Cask.generating_hash!` and `Cask.generated_hash!`
     #   are not idempotent so they can only be used in one test.
     it "returns the correct hash placeholders" do
       described_class.generating_hash!
diff --git a/Library/Homebrew/test/service_spec.rb b/Library/Homebrew/test/service_spec.rb
index 4f255d8aa8..f9089f012f 100644
--- a/Library/Homebrew/test/service_spec.rb
+++ b/Library/Homebrew/test/service_spec.rb
@@ -928,6 +928,8 @@ describe Homebrew::Service do
       }
     end
 
+    # @note The calls to `Formula.generating_hash!` and `Formula.generated_hash!`
+    #   are not idempotent so they can only be used in one test.
     it "replaces local paths with placeholders" do
       f = stub_formula do
         service do