Treat every Artifact instance as a single artifact.

Library/Homebrew/cask/lib/hbc/artifact.rb

@@ -33,7 +33,7 @@ module Artifact
     # We want to extract nested containers before we
     # handle any other artifacts.
     #
-    TYPES = [
+    CLASSES = [
       PreflightBlock,
       Uninstall,
       NestedContainer,
@@ -60,12 +60,9 @@ module Artifact
       Zap,
     ].freeze
 
-    def self.for_cask(cask, options = {})
+    def self.for_cask(cask)
       odebug "Determining which artifacts are present in Cask #{cask}"
-
-      TYPES
-        .select { |klass| klass.me?(cask) }
-        .map { |klass| klass.new(cask, options) }
+      CLASSES.flat_map { |klass| klass.for_cask(cask) }
     end
   end
 end

Library/Homebrew/cask/lib/hbc/artifact/base.rb → Library/Homebrew/cask/lib/hbc/artifact/abstract_artifact.rb

@@ -1,34 +1,28 @@
 module Hbc
   module Artifact
-    class Base
+    class AbstractArtifact
       extend Predicable
 
-      def self.artifact_name
-        @artifact_name ||= name.sub(/^.*:/, "").gsub(/(.)([A-Z])/, '\1_\2').downcase
+      def self.english_name
+        @english_name ||= name.sub(/^.*:/, "").gsub(/(.)([A-Z])/, '\1 \2')
       end
 
-      def self.artifact_english_name
-        @artifact_english_name ||= name.sub(/^.*:/, "").gsub(/(.)([A-Z])/, '\1 \2')
+      def self.english_article
+        @english_article ||= (english_name =~ /^[aeiou]/i) ? "an" : "a"
       end
 
-      def self.artifact_english_article
-        @artifact_english_article ||= (artifact_english_name =~ /^[aeiou]/i) ? "an" : "a"
+      def self.dsl_key
+        @dsl_key ||= name.sub(/^.*:/, "").gsub(/(.)([A-Z])/, '\1_\2').downcase.to_sym
       end
 
-      def self.artifact_dsl_key
-        @artifact_dsl_key ||= artifact_name.to_sym
+      def self.dirmethod
+        @dirmethod ||= "#{dsl_key}dir".to_sym
       end
 
-      def self.artifact_dirmethod
-        @artifact_dirmethod ||= "#{artifact_name}dir".to_sym
+      def self.for_cask(cask)
+        cask.artifacts[dsl_key].to_a
       end
 
-      def self.me?(cask)
-        cask.artifacts[artifact_dsl_key].any?
-      end
-
-      attr_reader :force
-
       # TODO: this sort of logic would make more sense in dsl.rb, or a
       #       constructor called from dsl.rb, so long as that isn't slow.
       def self.read_script_arguments(arguments, stanza, default_arguments = {}, override_arguments = {}, key = nil)
@@ -63,17 +57,14 @@ def self.read_script_arguments(arguments, stanza, default_arguments = {}, overri
         [executable, arguments]
       end
 
-      def summary
-        {}
-      end
+      attr_reader :cask
 
-      attr_predicate :force?, :verbose?
-
-      def initialize(cask, command: SystemCommand, force: false, verbose: false)
+      def initialize(cask)
         @cask = cask
-        @command = command
-        @force = force
-        @verbose = verbose
+      end
+
+      def to_s
+        "#{summarize} (#{self.class.english_name})"
       end
     end
   end

Library/Homebrew/cask/lib/hbc/artifact/abstract_flight_block.rb

@@ -1,39 +1,47 @@
-require "hbc/artifact/base"
+require "hbc/artifact/abstract_artifact"
 
 module Hbc
   module Artifact
-    class AbstractFlightBlock < Base
-      def self.artifact_dsl_key
+    class AbstractFlightBlock < AbstractArtifact
+      def self.dsl_key
         super.to_s.sub(/_block$/, "").to_sym
       end
 
-      def self.uninstall_artifact_dsl_key
-        artifact_dsl_key.to_s.prepend("uninstall_").to_sym
+      def self.uninstall_dsl_key
+        dsl_key.to_s.prepend("uninstall_").to_sym
       end
 
-      def self.class_for_dsl_key(dsl_key)
-        Object.const_get("Hbc::DSL::#{dsl_key.to_s.split("_").collect(&:capitalize).join}")
+      def self.for_cask(cask)
+        [dsl_key, uninstall_dsl_key].flat_map do |key|
+          [*cask.artifacts[key]].map { |block| new(cask, key => block) }
+        end
       end
 
-      def self.me?(cask)
-        cask.artifacts[artifact_dsl_key].any? ||
-          cask.artifacts[uninstall_artifact_dsl_key].any?
+      attr_reader :directives
+
+      def initialize(cask, **directives)
+        super(cask)
+        @directives = directives
       end
 
-      def install_phase
-        abstract_phase(self.class.artifact_dsl_key)
+      def install_phase(**)
+        abstract_phase(self.class.dsl_key)
       end
 
-      def uninstall_phase
-        abstract_phase(self.class.uninstall_artifact_dsl_key)
+      def uninstall_phase(**)
+        abstract_phase(self.class.uninstall_dsl_key)
       end
 
       private
 
+      def class_for_dsl_key(dsl_key)
+        namespace = self.class.name.to_s.sub(/::.*::.*$/, "")
+        self.class.const_get("#{namespace}::DSL::#{dsl_key.to_s.split("_").collect(&:capitalize).join}")
+      end
+
       def abstract_phase(dsl_key)
-        @cask.artifacts[dsl_key].each do |block|
-          self.class.class_for_dsl_key(dsl_key).new(@cask).instance_eval(&block)
-        end
+        return if (block = directives[dsl_key]).nil?
+        class_for_dsl_key(dsl_key).new(cask).instance_eval(&block)
       end
     end
   end