[refactor] Extract rendering functionality and cleanup code

Signed-off-by: Jacob Sheehy <[email protected]>

.rubocop.yml

@@ -27,3 +27,6 @@ Metrics/AbcSize:
 
 Metrics/ParameterLists:
   Max: 10
+
+Naming/MemoizedInstanceVariableName:
+  EnforcedStyleForLeadingUnderscores: required

bin/console

@@ -5,4 +5,5 @@ require 'bundler/setup'
 require 'blueprinter'
 
 require 'irb'
+
 IRB.start(__FILE__)

lib/blueprinter.rb

@@ -11,7 +11,7 @@ module Blueprinter
   class << self
     # @return [Configuration]
     def configuration
-      @configuration ||= Configuration.new
+      @_configuration ||= Configuration.new
     end
 
     def configure
@@ -20,7 +20,7 @@ def configure
 
     # Resets global configuration.
     def reset_configuration!
-      @configuration = nil
+      @_configuration = nil
     end
   end
 end

lib/blueprinter/configuration.rb

@@ -6,8 +6,21 @@
 
 module Blueprinter
   class Configuration
-    attr_accessor :association_default, :datetime_format, :deprecations, :field_default, :generator, :if, :method,
-                  :sort_fields_by, :unless, :extractor_default, :default_transformers, :custom_array_like_classes
+    attr_accessor(
+      :association_default,
+      :custom_array_like_classes,
+      :datetime_format,
+      :default_transformers,
+      :deprecations,
+      :extractor_default,
+      :field_default,
+      :generator,
+      :if,
+      :method,
+      :sort_fields_by,
+      :unless
+    )
+    attr_reader :extensions
 
     VALID_CALLABLES = %i[if unless].freeze
 
@@ -24,18 +37,15 @@ def initialize
       @extractor_default = AutoExtractor
       @default_transformers = []
       @custom_array_like_classes = []
-    end
-
-    def extensions
-      @extensions ||= Extensions.new
+      @extensions = Extensions.new
     end
 
     def extensions=(list)
       @extensions = Extensions.new(list)
     end
 
     def array_like_classes
-      @array_like_classes ||= [
+      @_array_like_classes ||= [
         Array,
         defined?(ActiveRecord::Relation) && ActiveRecord::Relation,
         *custom_array_like_classes

lib/blueprinter/errors/invalid_blueprint.rb

@@ -2,6 +2,6 @@
 
 module Blueprinter
   module Errors
-    class InvalidBlueprint < Blueprinter::BlueprinterError; end
+    class InvalidBlueprint < BlueprinterError; end
   end
 end

lib/blueprinter/errors/invalid_root.rb

@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+require 'blueprinter/blueprinter_error'
+
+module Blueprinter
+  module Errors
+    class InvalidRoot < BlueprinterError
+      def initialize(message = 'root key must be a Symbol or a String')
+        super
+      end
+    end
+  end
+end

lib/blueprinter/errors/meta_requires_root.rb

@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+require 'blueprinter/blueprinter_error'
+
+module Blueprinter
+  module Errors
+    class MetaRequiresRoot < BlueprinterError
+      def initialize(message = 'adding metadata requires that a root key is set')
+        super
+      end
+    end
+  end
+end

lib/blueprinter/extractors/association_extractor.rb

@@ -21,7 +21,7 @@ def extract(association_name, object, local_options, options = {})
 
       view = options[:view] || :default
       blueprint = association_blueprint(options[:blueprint], value)
-      blueprint.prepare(value, view_name: view, local_options: local_options)
+      blueprint.hashify(value, view_name: view, local_options: local_options)
     end
 
     private

lib/blueprinter/field.rb

@@ -26,15 +26,11 @@ def skip?(field_name, object, local_options)
     private
 
     def if_callable
-      return @if_callable if defined?(@if_callable)
-
-      @if_callable = callable_from(:if)
+      @_if_callable ||= callable_from(:if)
     end
 
     def unless_callable
-      return @unless_callable if defined?(@unless_callable)
-
-      @unless_callable = callable_from(:unless)
+      @_unless_callable ||= callable_from(:unless)
     end
 
     def callable_from(condition)

lib/blueprinter/reflection.rb

@@ -23,7 +23,7 @@ module Reflection
     # @return [Hash<Symbol, Blueprinter::Reflection::View>]
     #
     def reflections
-      @reflections ||= view_collection.views.transform_values do |view|
+      @_reflections ||= view_collection.views.transform_values do |view|
         View.new(view.name, view_collection)
       end
     end
@@ -45,7 +45,7 @@ def initialize(name, view_collection)
       # @return [Hash<Symbol, Blueprinter::Reflection::Field>]
       #
       def fields
-        @fields ||= @view_collection.fields_for(name).each_with_object({}) do |field, obj|
+        @_fields ||= @view_collection.fields_for(name).each_with_object({}) do |field, obj|
           next if field.options[:association]
 
           obj[field.name] = Field.new(field.method, field.name, field.options)
@@ -58,7 +58,7 @@ def fields
       # @return [Hash<Symbol, Blueprinter::Reflection::Association>]
       #
       def associations
-        @associations ||= @view_collection.fields_for(name).each_with_object({}) do |field, obj|
+        @_associations ||= @view_collection.fields_for(name).each_with_object({}) do |field, obj|
           next unless field.options[:association]
 
           blueprint = field.options.fetch(:blueprint)