Make Minitest/RefuteEqual aware of refute(expected == actual)

changelog/change_make_minitest_refute_equal_aware_of_refute_equal.md

@@ -0,0 +1 @@
+* [#265](https://github.com/rubocop/rubocop-minitest/pull/265): Make `Minitest/RefuteEqual` aware of `refute(expected == actual)`. ([@koic][])

lib/rubocop/cop/minitest/refute_equal.rb

@@ -9,6 +9,7 @@ module Minitest
       # @example
       #   # bad
       #   assert("rubocop-minitest" != actual)
+      #   refute("rubocop-minitest" == actual)
       #
       #   # good
       #   refute_equal("rubocop-minitest", actual)
@@ -18,17 +19,20 @@ class RefuteEqual < Base
         extend AutoCorrector
 
         MSG = 'Prefer using `refute_equal(%<preferred>s)`.'
-        RESTRICT_ON_SEND = %i[assert].freeze
+        RESTRICT_ON_SEND = %i[assert refute].freeze
 
-        def_node_matcher :assert_not_equal, <<~PATTERN
-          (send nil? :assert (send $_ :!= $_) $... )
+        def_node_matcher :assert_not_equal_or_refute_equal, <<~PATTERN
+          {
+            (send nil? :assert (send $_ :!= $_) $...)
+            (send nil? :refute (send $_ :== $_) $...)
+          }
         PATTERN
 
         def on_send(node)
           preferred = process_not_equal(node)
           return unless preferred
 
-          assert_not_equal(node) do |expected, actual|
+          assert_not_equal_or_refute_equal(node) do |expected, actual|
             message = format(MSG, preferred: preferred)
 
             add_offense(node, message: message) do |corrector|
@@ -51,7 +55,7 @@ def original_usage(first_part, custom_message)
         end
 
         def process_not_equal(node)
-          assert_not_equal(node) do |first_arg, second_arg, rest_args|
+          assert_not_equal_or_refute_equal(node) do |first_arg, second_arg, rest_args|
             custom_message = rest_args.first
 
             preferred_usage(first_arg, second_arg, custom_message)

test/rubocop/cop/minitest/refute_equal_test.rb

@@ -79,6 +79,25 @@ def test_do_something
     RUBY
   end
 
+  def test_registers_offense_when_using_refute_equal_operator
+    assert_offense(<<~RUBY)
+      class FooTest < Minitest::Test
+        def test_do_something
+          refute('rubocop-minitest' == actual)
+          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Prefer using `refute_equal('rubocop-minitest', actual)`.
+        end
+      end
+    RUBY
+
+    assert_correction(<<~RUBY)
+      class FooTest < Minitest::Test
+        def test_do_something
+          refute_equal('rubocop-minitest', actual)
+        end
+      end
+    RUBY
+  end
+
   def test_does_not_register_offense_when_using_negate_equals
     assert_no_offenses(<<~RUBY)
       class FooTest < Minitest::Test