Enhance AssertSame/RefuteSame to check for object_id comparison

.rubocop.yml

@@ -56,6 +56,11 @@ Style/FormatStringToken:
   Exclude:
     - test/**/*
 
+Style/DocumentDynamicEvalDefinition:
+  Exclude:
+    - 'lib/rubocop/cop/mixin/minitest_cop_rule.rb'
+    - 'lib/rubocop/cop/mixin/assert_refute_same_helper.rb'
+
 Metrics/ClassLength:
   Exclude:
     - test/**/*

.rubocop_todo.yml

@@ -12,8 +12,3 @@ Metrics/MethodLength:
   Max: 14
   Exclude:
     - 'test/rubocop/cop/minitest/global_expectations_test.rb'
-
-# Offense count: 1
-Style/DocumentDynamicEvalDefinition:
-  Exclude:
-    - 'lib/rubocop/cop/mixin/minitest_cop_rule.rb'

changelog/change_assert_same_check_object_ids.md

@@ -0,0 +1 @@
+* [#276](https://github.com/rubocop/rubocop-minitest/pull/276): Enhance `AssertSame`/`RefuteSame` to check for `object_id` comparison. ([@fatkodima][])

lib/rubocop/cop/minitest/assert_same.rb

@@ -12,14 +12,15 @@ module Minitest
       # @example
       #   # bad
       #   assert(expected.equal?(actual))
+      #   assert_equal(expected.object_id, actual.object_id)
       #
       #   # good
       #   assert_same(expected, actual)
       #
       class AssertSame < Base
-        extend MinitestCopRule
+        extend AssertRefuteSameHelper
 
-        define_rule :assert, target_method: :equal?, preferred_method: :assert_same
+        define_rule :assert
       end
     end
   end

lib/rubocop/cop/minitest/refute_same.rb

@@ -12,14 +12,15 @@ module Minitest
       # @example
       #   # bad
       #   refute(expected.equal?(actual))
+      #   refute_equal(expected.object_id, actual.object_id)
       #
       #   # good
       #   refute_same(expected, actual)
       #
       class RefuteSame < Base
-        extend MinitestCopRule
+        extend AssertRefuteSameHelper
 
-        define_rule :refute, target_method: :equal?, preferred_method: :refute_same
+        define_rule :refute
       end
     end
   end

lib/rubocop/cop/minitest_cops.rb

@@ -7,6 +7,7 @@
 require_relative 'mixin/minitest_exploration_helpers'
 require_relative 'mixin/nil_assertion_handleable'
 require_relative 'mixin/predicate_assertion_handleable'
+require_relative 'mixin/assert_refute_same_helper'
 require_relative 'minitest/assert_empty'
 require_relative 'minitest/assert_empty_literal'
 require_relative 'minitest/assert_equal'

lib/rubocop/cop/mixin/assert_refute_same_helper.rb

@@ -0,0 +1,57 @@
+# frozen_string_literal: true
+
+module RuboCop
+  module Cop
+    # Provide a method to define offense rule for Minitest cops.
+    module AssertRefuteSameHelper
+      def define_rule(assertion_method)
+        class_eval(<<~RUBY, __FILE__, __LINE__ + 1)
+          extend AutoCorrector
+
+          MSG = 'Prefer using `#{assertion_method}_same(%<new_arguments>s)`.'
+          RESTRICT_ON_SEND = %i[#{assertion_method} #{assertion_method}_equal]
+
+          def_node_matcher :assertion_with_equal?, <<~PATTERN
+            (send nil? :#{assertion_method}
+              $(send $_ :equal? $_)
+              $_?)
+          PATTERN
+
+          def_node_matcher :equality_with_object_id?, <<~PATTERN
+            (send nil? :#{assertion_method}_equal
+              (send $_ :object_id)
+              (send $_ :object_id)
+              $_?)
+          PATTERN
+
+          def on_send(node)
+            if (equal_node, expected_node, actual_node, message_node = assertion_with_equal?(node))
+              add_offense(node, message: message(expected_node, actual_node, message_node.first)) do |corrector|
+                corrector.replace(node.loc.selector, "#{assertion_method}_same")
+                corrector.replace(equal_node, "\#{expected_node.source}, \#{actual_node.source}")
+              end
+            elsif (expected_node, actual_node, message_node = equality_with_object_id?(node))
+              add_offense(node, message: message(expected_node, actual_node, message_node.first)) do |corrector|
+                corrector.replace(node.loc.selector, "#{assertion_method}_same")
+                remove_method_call(expected_node.parent, corrector)
+                remove_method_call(actual_node.parent, corrector)
+              end
+            end
+          end
+
+          private
+
+          def message(expected_node, actual_node, message_node)
+            arguments = [expected_node, actual_node, message_node].compact.map(&:source).join(", ")
+            format(MSG, new_arguments: arguments)
+          end
+
+          def remove_method_call(send_node, corrector)
+            range = send_node.loc.dot.join(send_node.loc.selector)
+            corrector.remove(range)
+          end
+        RUBY
+      end
+    end
+  end
+end

test/rubocop/cop/minitest/assert_same_test.rb

@@ -85,6 +85,25 @@ def test_do_something
     RUBY
   end
 
+  def test_registers_offense_when_using_assert_equal_with_object_id
+    assert_offense(<<~RUBY)
+      class FooTest < Minitest::Test
+        def test_do_something
+          assert_equal(expected.object_id, actual.object_id)
+          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Prefer using `assert_same(expected, actual)`.
+        end
+      end
+    RUBY
+
+    assert_correction(<<~RUBY)
+      class FooTest < Minitest::Test
+        def test_do_something
+          assert_same(expected, actual)
+        end
+      end
+    RUBY
+  end
+
   def test_does_not_register_offense_when_using_assert_same
     assert_no_offenses(<<~RUBY)
       class FooTest < Minitest::Test

test/rubocop/cop/minitest/refute_same_test.rb

@@ -85,6 +85,25 @@ def test_do_something
     RUBY
   end
 
+  def test_registers_offense_when_using_refute_equal_with_object_id
+    assert_offense(<<~RUBY)
+      class FooTest < Minitest::Test
+        def test_do_something
+          refute_equal(expected.object_id, actual.object_id)
+          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Prefer using `refute_same(expected, actual)`.
+        end
+      end
+    RUBY
+
+    assert_correction(<<~RUBY)
+      class FooTest < Minitest::Test
+        def test_do_something
+          refute_same(expected, actual)
+        end
+      end
+    RUBY
+  end
+
   def test_does_not_register_offense_when_using_assert_same
     assert_no_offenses(<<~RUBY)
       class FooTest < Minitest::Test