Remove +Parser+ dependencies as class loading time

We deliberately only load `parser` when there a console session starts,
so we need to remove references from class declarations.

lib/console1984/command_validator/.command_parser.rb

@@ -0,0 +1,69 @@
+# Naming class with dot so that it doesn't get loaded eagerly by Zeitwork. We want to load
+# only when a console session is started, when +parser+ is loaded.
+#
+# See +Console1984::Supervisor#require_dependencies+
+class Console1984::CommandValidator::CommandParser < ::Parser::AST::Processor
+  include AST::Processor::Mixin
+  include Console1984::Freezeable
+
+  def initialize
+    @constants = []
+    @declared_classes_or_modules = []
+    @constant_assignments = []
+  end
+
+  # We define accessors to define lists without duplicates. We are not using a +SortedSet+ because we want
+  # to mutate strings in the list while the processing is happening. And we don't use metapgroamming to define the
+  # accessors to prevent having problems with freezable and its instance_variable* protection.
+
+  def constants
+    @constants.uniq
+  end
+
+  def declared_classes_or_modules
+    @declared_classes_or_modules.uniq
+  end
+
+  def constant_assignments
+    @constant_assignments.uniq
+  end
+
+  def on_class(node)
+    super
+    const_declaration, _, _ = *node
+    constant = extract_constants(const_declaration).first
+    @declared_classes_or_modules << constant if constant.present?
+  end
+
+  alias_method :on_module, :on_class
+
+  def on_const(node)
+    super
+    name, const_name = *node
+    const_name = const_name.to_s
+    last_constant = @constants.last
+
+    if name.nil? || (name && name.type == :cbase) # cbase = leading ::
+      if last_constant&.end_with?("::")
+        last_constant << const_name
+      else
+        @constants << const_name
+      end
+    elsif last_constant
+      last_constant << "::#{const_name}"
+    end
+  end
+
+  def on_casgn(node)
+    super
+    scope_node, name, value_node = *node
+    @constant_assignments.push(*extract_constants(value_node))
+  end
+
+  private
+    def extract_constants(node)
+      self.class.new.tap do |processor|
+        processor.process(node)
+      end.constants
+    end
+end

lib/console1984/command_validator/parsed_command.rb

@@ -6,85 +6,19 @@ class Console1984::CommandValidator::ParsedCommand
 
   attr_reader :raw_command
 
-  delegate :declared_classes_or_modules, :constants, :constant_assignments, to: :processed_ast
+  delegate :declared_classes_or_modules, :constants, :constant_assignments, to: :command_parser
 
   def initialize(raw_command)
     @raw_command = Array(raw_command).join("\n")
   end
 
   private
-    def processed_ast
-      @processed_ast ||= CommandProcessor.new.tap do |processor|
+    def command_parser
+      @command_parser ||= Console1984::CommandValidator::CommandParser.new.tap do |processor|
         ast = Parser::CurrentRuby.parse(raw_command)
         processor.process(ast)
       rescue Parser::SyntaxError
         # Fail open with syntax errors
       end
     end
-
-    class CommandProcessor < ::Parser::AST::Processor
-      include AST::Processor::Mixin
-      include Console1984::Freezeable
-
-      def initialize
-        @constants = []
-        @declared_classes_or_modules = []
-        @constant_assignments = []
-      end
-
-      # We define accessors to define lists without duplicates. We are not using a +SortedSet+ because we want
-      # to mutate strings in the list while the processing is happening. And we don't use metapgroamming to define the
-      # accessors to prevent having problems with freezable and its instance_variable* protection.
-
-      def constants
-        @constants.uniq
-      end
-
-      def declared_classes_or_modules
-        @declared_classes_or_modules.uniq
-      end
-
-      def constant_assignments
-        @constant_assignments.uniq
-      end
-
-      def on_class(node)
-        super
-        const_declaration, _, _ = *node
-        constant = extract_constants(const_declaration).first
-        @declared_classes_or_modules << constant if constant.present?
-      end
-
-      alias_method :on_module, :on_class
-
-      def on_const(node)
-        super
-        name, const_name = *node
-        const_name = const_name.to_s
-        last_constant = @constants.last
-
-        if name.nil? || (name && name.type == :cbase) # cbase = leading ::
-          if last_constant&.end_with?("::")
-            last_constant << const_name
-          else
-            @constants << const_name
-          end
-        elsif last_constant
-          last_constant << "::#{const_name}"
-        end
-      end
-
-      def on_casgn(node)
-        super
-        scope_node, name, value_node = *node
-        @constant_assignments.push(*extract_constants(value_node))
-      end
-
-      private
-        def extract_constants(node)
-          self.class.new.tap do |processor|
-            processor.process(node)
-          end.constants
-        end
-    end
 end

lib/console1984/refrigerator.rb

@@ -11,14 +11,17 @@ def freeze_all
   end
 
   private
-    EXTERNAL_MODULES_AND_CLASSES_TO_FREEZE = [Parser::CurrentRuby]
-
     def freeze_internal_instances
       Console1984.config.freeze unless Console1984.config.test_mode
     end
 
     def freeze_external_modules_and_classes
-      EXTERNAL_MODULES_AND_CLASSES_TO_FREEZE.each { |klass| klass.include(Console1984::Freezeable) }
+      external_modules_and_classes_to_freeze.each { |klass| klass.include(Console1984::Freezeable) }
+    end
+
+    def external_modules_and_classes_to_freeze
+      # Not using a constant because we want this to run lazily (console-dependant dependencies might not be loaded).
+      [Parser::CurrentRuby]
     end
 
     def eager_load_all_classes

lib/console1984/supervisor.rb

@@ -41,6 +41,10 @@ def require_dependencies
         require 'parser/current'
       end
       require 'colorized_string'
+
+      # Explicit lazy loading because it depends on +parser+, which we want to only load
+      # in console sessions.
+      require_relative "./command_validator/.command_parser"
     end
 
     def start_session