Add Entity class for basic entity methods implementation

lib/pubid/core.rb

@@ -15,3 +15,4 @@
 require_relative "core/harmonized_stage_code"
 require_relative "core/stage"
 require_relative "core/typed_stage"
+require_relative "core/entity"

lib/pubid/core/entity.rb

@@ -0,0 +1,11 @@
+module Pubid::Core
+  class Entity
+    def ==(other)
+      instance_variables.map do |var|
+        return false unless instance_variable_get(var) == other.instance_variable_get(var)
+      end
+
+      true
+    end
+  end
+end

spec/pubid_core/entity_spec.rb

@@ -0,0 +1,36 @@
+module Pubid::Core
+  class TestEntity < Entity
+    attr_accessor :type, :number
+
+    def initialize(type:,number:)
+      @number, @type = number, type
+    end
+  end
+
+  RSpec.describe TestEntity do
+    describe "#==" do
+      subject do
+        first_entity == second_entity
+      end
+
+      let(:first_entity) do
+        described_class.new(number: 1, type: 2)
+      end
+      let(:second_entity) do
+        described_class.new(number: 1, type: 2)
+      end
+
+      context "when have equal entity parameters" do
+        it { is_expected.to be_truthy }
+      end
+
+      context "when different parameters" do
+        let(:second_entity) do
+          described_class.new(number: 1, type: 3)
+        end
+
+        it { is_expected.to be_falsey }
+      end
+    end
+  end
+end