Add struct formatter

.rubocop.yml

@@ -6,6 +6,8 @@ Style/SymbolArray:
   EnforcedStyle: brackets
 Style/WordArray:
   EnforcedStyle: brackets
+Style/OpenStructUse:
+  Enabled: false
 Metrics/BlockLength:
   Exclude:
     - 'spec/**/*_spec.rb'
@@ -15,3 +17,5 @@ Layout/EndAlignment:
   EnforcedStyleAlignWith: variable
 Layout/FirstArrayElementIndentation:
   EnforcedStyle: consistent
+Gemspec/DevelopmentDependencies:
+  Enabled: false

lib/nazar.rb

@@ -38,12 +38,12 @@ module Nazar # rubocop:disable Metrics/ModuleLength
 
   setting :enable_shorthand_method, default: true
 
-  class << self
+  class << self # rubocop:disable Metrics/ClassLength
     def formatters
       @formatters ||= Set.new
     end
 
-    def enable!(extensions: [:active_record, :csv])
+    def enable!(extensions: [:active_record, :csv, :struct])
       return if @enabled
 
       load_extensions!(extensions)
@@ -67,6 +67,12 @@ def load_csv!
       register_formatter!('CSVTable', 'nazar/formatter/csv_table')
     end
 
+    def load_struct!
+      require 'ostruct'
+
+      register_formatter!('Struct', 'nazar/formatter/struct')
+    end
+
     def load_active_record!
       require 'active_record'
 
@@ -113,6 +119,7 @@ def disable!
     def load_extensions!(extensions)
       load_active_record! if extensions.include?(:active_record)
       load_csv! if extensions.include?(:csv)
+      load_struct! if extensions.include?(:struct)
       load_sequel! if extensions.include?(:sequel)
     end
 

lib/nazar/formatter/active_record_collection.rb

@@ -16,6 +16,8 @@ def initialize(collection)
       end
 
       def self.valid?(data)
+        return false if data.is_a?(Struct) || (defined?(OpenStruct) && data.is_a?(OpenStruct))
+
         data.is_a?(ActiveRecord::Associations::CollectionProxy) ||
           data.is_a?(ActiveRecord::Relation) ||
           (data.is_a?(Enumerable) && data.first.is_a?(ActiveRecord::Base))

lib/nazar/formatter/generic.rb

@@ -27,10 +27,10 @@ def summary
       end
 
       def self.valid?(data)
-        item = data&.first
-        compatible = item.respond_to?(:keys) && item.respond_to?(:values)
+        return false unless data.is_a?(Enumerable)
 
-        data.is_a?(Enumerable) && (item.is_a?(Struct) || compatible)
+        item = data&.first
+        item.respond_to?(:keys) && item.respond_to?(:values)
       end
 
       def valid?

lib/nazar/formatter/struct.rb

@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+module Nazar
+  module Formatter
+    class Struct
+      def initialize(item)
+        @collection = Array(item)
+        @attributes = item.to_h.keys
+        @item = item
+      end
+
+      def self.valid?(data)
+        data.is_a?(::Struct) || data.is_a?(::OpenStruct)
+      end
+
+      def valid?
+        true
+      end
+
+      def headers
+        HeadersFormatter.new(attributes).format
+      end
+
+      def cells
+        @cells ||= @collection.map do |item|
+          item.each_pair do |_, value|
+            CellFormatter.new(value, type: nil).format
+          end
+        end
+      end
+    end
+  end
+end

lib/nazar/version.rb

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module Nazar
-  VERSION = '1.2.0'
+  VERSION = '1.3.0'
 end

spec/nazar/view_spec.rb

@@ -62,6 +62,30 @@
         end
       end
     end
+
+    context 'with Struct' do
+      let(:data) { Struct.new(:id, :name).new(1, 'foo') }
+
+      context 'without loaded extension' do
+        it do
+          expect(subject).not_to be_supported_data
+        end
+      end
+
+      context 'with loaded extension' do
+        before do
+          Nazar.load_struct!
+        end
+
+        after do
+          unload_struct!
+        end
+
+        it do
+          expect(subject).to be_supported_data
+        end
+      end
+    end
   end
 
   describe '#render' do

spec/nazar_spec.rb

@@ -15,7 +15,7 @@
 
     context 'when Pry is defined' do
       it do
-        ::Pry = double
+        ::Pry = double # rubocop:disable Style/RedundantConstantBase
 
         expect(Nazar).to receive(:enable_for_pry!)
         expect(Nazar).not_to receive(:enable_for_irb!)
@@ -26,7 +26,7 @@
 
     context 'when IRB is defined' do
       it do
-        ::IRB = double
+        ::IRB = double # rubocop:disable Style/RedundantConstantBase
 
         expect(Nazar).not_to receive(:enable_for_pry!)
         expect(Nazar).to receive(:enable_for_irb!)

spec/spec_helper.rb

@@ -24,6 +24,10 @@ def unload_sequel!
       Nazar.formatters.delete(Nazar::Formatter::SequelCollection)
       Nazar.formatters.delete(Nazar::Formatter::SequelItem)
     end
+
+    def unload_struct!
+      Nazar.formatters.delete(Nazar::Formatter::Struct)
+    end
   end
 end