Cleanup defined? usage

Now that we dropped support for Ruby 2.7, we no longer
need to check if variables are defined before accessing them
to avoid the undefined variable warning.

actionpack/lib/action_dispatch/testing/assertions/routing.rb

@@ -248,7 +248,7 @@ def assert_routing(path, options, defaults = {}, extras = {}, message = nil)
 
       # ROUTES TODO: These assertions should really work in an integration context
       def method_missing(selector, ...)
-        if defined?(@controller) && @controller && defined?(@routes) && @routes && @routes.named_routes.route_defined?(selector)
+        if @controller && @routes&.named_routes.route_defined?(selector)
           @controller.public_send(selector, ...)
         else
           super
@@ -258,7 +258,7 @@ def method_missing(selector, ...)
       private
         def create_routes
           @routes = ActionDispatch::Routing::RouteSet.new
-          if defined?(@controller) && @controller
+          if @controller
             @controller = @controller.clone
             _routes = @routes
 
@@ -282,7 +282,7 @@ def create_routes
 
         def reset_routes(old_routes, old_controller)
           @routes = old_routes
-          if defined?(@controller) && @controller
+          if @controller
             @controller = old_controller
           end
         end

actionview/lib/action_view/test_case.rb

@@ -433,7 +433,7 @@ def method_missing(selector, ...)
 
       def respond_to_missing?(name, include_private = false)
         begin
-          routes = defined?(@controller) && @controller.respond_to?(:_routes) && @controller._routes
+          routes = @controller.respond_to?(:_routes) && @controller._routes
         rescue
           # Don't call routes, if there is an error on _routes call
         end

activejob/lib/active_job/core.rb

@@ -196,7 +196,7 @@ def deserialize_arguments(serialized_args)
       end
 
       def arguments_serialized?
-        defined?(@serialized_arguments) && @serialized_arguments
+        @serialized_arguments
       end
   end
 end

activemodel/lib/active_model/attribute.rb

@@ -153,7 +153,7 @@ def original_value_for_database
       alias :assigned? :original_attribute
 
       def initialize_dup(other)
-        if defined?(@value) && @value.duplicable?
+        if @value&.duplicable?
           @value = @value.dup
         end
       end

activerecord/lib/active_record/associations/preloader/through_association.rb

@@ -9,9 +9,7 @@ def preloaded_records
         end
 
         def records_by_owner
-          return @records_by_owner if defined?(@records_by_owner)
-
-          @records_by_owner = owners.each_with_object({}) do |owner, result|
+          @records_by_owner ||= owners.each_with_object({}) do |owner, result|
             if loaded?(owner)
               result[owner] = target_for(owner)
               next

activerecord/lib/active_record/attribute_methods.rb

@@ -137,7 +137,7 @@ def define_attribute_methods # :nodoc:
 
       def undefine_attribute_methods # :nodoc:
         GeneratedAttributeMethods::LOCK.synchronize do
-          super if defined?(@attribute_methods_generated) && @attribute_methods_generated
+          super if @attribute_methods_generated
           @attribute_methods_generated = false
           @alias_attributes_mass_generated = false
         end
@@ -288,9 +288,7 @@ def respond_to?(name, include_private = false)
 
       # If the result is true then check for the select case.
       # For queries selecting a subset of columns, return false for unselected columns.
-      # We check defined?(@attributes) not to issue warnings if called on objects that
-      # have been allocated but not yet initialized.
-      if defined?(@attributes)
+      if @attributes
         if name = self.class.symbol_column_to_string(name.to_sym)
           return _has_attribute?(name)
         end
@@ -460,8 +458,7 @@ def accessed_fields
 
     private
       def attribute_method?(attr_name)
-        # We check defined? because Syck calls respond_to? before actually calling initialize.
-        defined?(@attributes) && @attributes.key?(attr_name)
+        @attributes&.key?(attr_name)
       end
 
       def attributes_with_values(attribute_names)

activerecord/lib/active_record/connection_handling.rb

@@ -258,7 +258,7 @@ def connection
 
     # Return the connection specification name from the current class or its parent.
     def connection_specification_name
-      if !defined?(@connection_specification_name) || @connection_specification_name.nil?
+      if @connection_specification_name.nil?
         return self == Base ? Base.name : superclass.connection_specification_name
       end
       @connection_specification_name

activerecord/lib/active_record/core.rb

@@ -720,7 +720,7 @@ def full_inspect
     def pretty_print(pp)
       return super if custom_inspect_method_defined?
       pp.object_address_group(self) do
-        if defined?(@attributes) && @attributes
+        if @attributes
           attr_names = attributes_for_inspect.select { |name| _has_attribute?(name.to_s) }
           pp.seplist(attr_names, proc { pp.text "," }) do |attr_name|
             attr_name = attr_name.to_s
@@ -791,9 +791,7 @@ def inspection_filter
       end
 
       def inspect_with_attributes(attributes_to_list)
-        # We check defined?(@attributes) not to issue warnings if the object is
-        # allocated but not initialized.
-        inspection = if defined?(@attributes) && @attributes
+        inspection = if @attributes
           attributes_to_list.filter_map do |name|
             name = name.to_s
             if _has_attribute?(name)

activerecord/lib/active_record/inheritance.rb

@@ -165,7 +165,7 @@ def base_class?
 
       # Returns whether this class is an abstract class or not.
       def abstract_class?
-        defined?(@abstract_class) && @abstract_class == true
+        @abstract_class == true
       end
 
       # Sets the application record class for Active Record

activerecord/lib/active_record/model_schema.rb

@@ -273,7 +273,7 @@ def table_name=(value)
         @table_name        = value
         @quoted_table_name = nil
         @arel_table        = nil
-        @sequence_name     = nil unless defined?(@explicit_sequence_name) && @explicit_sequence_name
+        @sequence_name     = nil unless @explicit_sequence_name
         @predicate_builder = nil
       end
 
@@ -414,11 +414,10 @@ def table_exists?
       end
 
       def attributes_builder # :nodoc:
-        unless defined?(@attributes_builder) && @attributes_builder
+        @attributes_builder ||= begin
           defaults = _default_attributes.except(*(column_names - [primary_key]))
-          @attributes_builder = ActiveModel::AttributeSet::Builder.new(attribute_types, defaults)
+          ActiveModel::AttributeSet::Builder.new(attribute_types, defaults)
         end
-        @attributes_builder
       end
 
       def columns_hash # :nodoc:
@@ -573,7 +572,7 @@ def inherited(child_class)
         end
 
         def schema_loaded?
-          defined?(@schema_loaded) && @schema_loaded
+          @schema_loaded
         end
 
         def load_schema!

activerecord/lib/active_record/relation/query_methods.rb

@@ -1575,8 +1575,7 @@ def build_join_dependencies
       end
 
       def assert_mutability!
-        raise ImmutableRelation if @loaded
-        raise ImmutableRelation if defined?(@arel) && @arel
+        raise ImmutableRelation if @loaded || @arel
       end
 
       def build_arel(aliases = nil)

activerecord/lib/active_record/touch_later.rb

@@ -64,7 +64,7 @@ def touch_deferred_attributes
       end
 
       def has_defer_touch_attrs?
-        defined?(@_defer_touch_attrs) && @_defer_touch_attrs.present?
+        @_defer_touch_attrs.present?
       end
   end
 end

activerecord/test/cases/adapters/postgresql/geometric_test.rb

@@ -257,7 +257,7 @@ class PostgresqlLine < ActiveRecord::Base; end
   end
 
   teardown do
-    if defined?(@connection)
+    if @connection
       @connection.drop_table "postgresql_lines", if_exists: true
     end
   end

activestorage/lib/active_storage/previewer/mupdf_previewer.rb

@@ -12,7 +12,7 @@ def mutool_path
       end
 
       def mutool_exists?
-        return @mutool_exists if defined?(@mutool_exists) && !@mutool_exists.nil?
+        return @mutool_exists unless @mutool_exists.nil?
 
         system mutool_path, out: File::NULL, err: File::NULL
 

activestorage/lib/active_storage/previewer/poppler_pdf_previewer.rb

@@ -12,7 +12,7 @@ def pdftoppm_path
       end
 
       def pdftoppm_exists?
-        return @pdftoppm_exists if defined?(@pdftoppm_exists)
+        return @pdftoppm_exists unless @pdftoppm_exists.nil?
 
         @pdftoppm_exists = system(pdftoppm_path, "-v", out: File::NULL, err: File::NULL)
       end

activestorage/lib/active_storage/previewer/video_previewer.rb

@@ -10,7 +10,7 @@ def accept?(blob)
       end
 
       def ffmpeg_exists?
-        return @ffmpeg_exists if defined?(@ffmpeg_exists)
+        return @ffmpeg_exists unless @ffmpeg_exists.nil?
 
         @ffmpeg_exists = system(ffmpeg_path, "-version", out: File::NULL, err: File::NULL)
       end

activesupport/lib/active_support/cache.rb

@@ -344,7 +344,7 @@ def silence!
 
       # Silences the logger within a block.
       def mute
-        previous_silence, @silence = defined?(@silence) && @silence, true
+        previous_silence, @silence = @silence, true
         yield
       ensure
         @silence = previous_silence

activesupport/test/cache/behaviors/cache_logging_behavior.rb

@@ -77,7 +77,7 @@ def assert_logs(pattern, &block)
       assert_match pattern, io.string
     end
 
-    def key_pattern(key, namespace: defined?(@namespace) && @namespace)
+    def key_pattern(key, namespace: @namespace)
       /#{Regexp.escape namespace.to_s}#{":" if namespace}#{Regexp.escape key}/
     end
 end

railties/lib/rails/application/configuration.rb

@@ -378,9 +378,7 @@ def log_level=(level)
         @broadcast_log_level = level
       end
 
-      def broadcast_log_level # :nodoc:
-        defined?(@broadcast_log_level) ? @broadcast_log_level : nil
-      end
+      attr_reader :broadcast_log_level # :nodoc:
 
       def debug_exception_response_format
         @debug_exception_response_format || :default

railties/lib/rails/commands/dbconsole/dbconsole_command.rb

@@ -21,25 +21,24 @@ def start
     end
 
     def db_config
-      return @db_config if defined?(@db_config)
-
-      # If the user provided a database, use that. Otherwise find
-      # the first config in the database.yml
-      if database
-        @db_config = configurations.configs_for(env_name: environment, name: database, include_hidden: true)
-      else
-        @db_config = configurations.find_db_config(environment)
+      @db_config ||= begin
+        # If the user provided a database, use that. Otherwise find
+        # the first config in the database.yml
+        config = if database
+          @db_config = configurations.configs_for(env_name: environment, name: database, include_hidden: true)
+        else
+          @db_config = configurations.find_db_config(environment)
+        end
+
+        unless config
+          missing_db = database ? "'#{database}' database is not" : "No databases are"
+          raise ActiveRecord::AdapterNotSpecified,
+            "#{missing_db} configured for '#{environment}'. Available configuration: #{configurations.inspect}"
+        end
+
+        config.validate!
+        config
       end
-
-      unless @db_config
-        missing_db = database ? "'#{database}' database is not" : "No databases are"
-        raise ActiveRecord::AdapterNotSpecified,
-          "#{missing_db} configured for '#{environment}'. Available configuration: #{configurations.inspect}"
-      end
-
-      @db_config.validate!
-
-      @db_config
     end
 
     def database

railties/lib/rails/generators/rails/app/app_generator.rb

@@ -266,7 +266,7 @@ def vendor
     end
 
     def config_target_version
-      defined?(@config_target_version) ? @config_target_version : Rails::VERSION::STRING.to_f
+      @config_target_version || Rails::VERSION::STRING.to_f
     end
   end