Refactor action_mapping to use its own configuration object

lib/blacklight/configuration.rb

@@ -211,14 +211,14 @@ def initialized_default_configuration?
 
       # @!attribute action_mapping
       # @since v7.16.0
-      # @return [Hash{Symbol => Blacklight::Configuration::ViewConfig}]
+      # @return [Hash{Symbol => Blacklight::Configuration::ActionConfigMapEntry}]
       property :action_mapping, default: NestedOpenStructWithHashAccess.new(
-        ViewConfig,
-        default: { top_level_config: :index },
-        show: { top_level_config: :show },
-        citation: { parent_config: :show },
-        email_record: { top_level_config: :email },
-        sms_record: { top_level_config: :sms }
+        ActionConfigMapEntry,
+        default: { blacklight_config_property: :index, default: [:index] },
+        show: { blacklight_config_property: :show },
+        citation: { parent_action_key: :show },
+        email_record: { blacklight_config_property: :email },
+        sms_record: { blacklight_config_property: :sms }
       )
 
       # @!attribute sms
@@ -528,12 +528,7 @@ def view_config(view_type = nil, action_name: :index)
         view_type = nil
       end
 
-      @view_config[[view_type, action_name]] ||= if view_type.nil?
-                                                   action_config(action_name)
-                                                 else
-                                                   base_config = action_config(action_name)
-                                                   base_config.merge(view.fetch(view_type, {}))
-                                                 end
+      @view_config[[view_type, action_name]] ||= action_config(action_name, (view.fetch(view_type, nil) if view_type))
     end
 
     # YARD will include inline disabling as docs, cannot do multiline inside @!macro.  AND this must be separate from doc block.
@@ -646,8 +641,8 @@ def _deep_copy(value)
       end
     end
 
-    def action_config(action, default: :index)
-      action_config = action_mapping[action]
+    def action_config(action_name, view_type_specific_config, default: :index)
+      action_config = action_mapping[action_name]
       action_config ||= action_mapping[:default]
 
       if action_config.parent_config && action_config.parent_config != :default
@@ -658,9 +653,19 @@ def action_config(action, default: :index)
       end
       action_config = action_config.reverse_merge(action_mapping[:default]) if action_config != action_mapping[:default]
 
-      action_config = action_config.reverse_merge(self[action_config.top_level_config]) if action_config.top_level_config
-      action_config = action_config.reverse_merge(show) if default == :show && action_config.top_level_config != :show
-      action_config.reverse_merge(index)
+      view_config = if action_config.blacklight_config_property
+                      self[action_config.blacklight_config_property]
+                    else
+                      self[default]
+                    end
+
+      view_config = Array(action_config.default - [action_config.blacklight_config_property || default]).inject(view_config) do |config, top_level_config|
+        config.reverse_merge(self[top_level_config])
+      end
+
+      view_config = view_config.merge(view_type_specific_config) if view_type_specific_config
+
+      view_config
     end
   end
 end

lib/blacklight/configuration/action_config_map_entry.rb

@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+
+module Blacklight
+  class Configuration::ActionConfigMapEntry < OpenStructWithHashAccess
+    # @!attribute parent_action_key
+    # Pull in the configuration for this action from another action's config
+    # @return [Symbol]
+
+    def parent_config = parent_action_key
+
+    def parent_config=(value)
+      self.parent_action_key = value
+    end
+
+    #
+    # @!attribute blacklight_config_property
+    # Pull in the configuration for this action from a top-level config
+    # @return [Symbol]
+
+    def top_level_config = blacklight_config_property
+
+    def top_level_config=(value)
+      self.blacklight_config_property = value
+    end
+
+    #
+    # @!attribute default
+    # Pull in additional default configuration for this action from a top-level config
+    # @return [Array<Symbol>]
+  end
+end

spec/models/blacklight/configuration_spec.rb

@@ -670,25 +670,6 @@
         expect(config.view_config(action_name: :show)).to have_attributes config.show.to_h
       end
 
-      it 'includes the default action mapping configuration' do
-        config.action_mapping.default.whatever = :some_value
-
-        expect(config.view_config(action_name: :show)).to have_attributes whatever: :some_value
-      end
-
-      it 'includes the action-specific mappings' do
-        config.action_mapping.foo.document_presenter_class = Blacklight::DocumentPresenter
-
-        expect(config.view_config(action_name: :foo)).to have_attributes config.action_mapping.foo.to_h
-      end
-
-      it 'allows the action mapping to specific a parent configuration with some more defaults' do
-        config.action_mapping.foo.parent_config = :bar
-        config.action_mapping.bar.whatever = :bar_value
-
-        expect(config.view_config(action_name: :foo)).to have_attributes whatever: :bar_value
-      end
-
       context 'with the :citation action' do
         it 'also includes the show config' do
           expect(config.view_config(action_name: :citation)).to have_attributes config.show.to_h