[Fix #183] Fix an error for Minitest/AssertMatch

changelog/fix_an_error_for_minitest_assert_match.md

@@ -0,0 +1 @@
+* [#183](https://github.com/rubocop/rubocop-minitest/issues/183): Fix an error for `Minitest/AssertMatch` when using `assert` with no arguments `match`. ([@koic][])

lib/rubocop/cop/mixin/minitest_cop_rule.rb

@@ -36,7 +36,8 @@ def define_rule(assertion_method, target_method:, preferred_method: nil, inverse
           def on_send(node)
             return unless node.method?(:#{assertion_method})
             return unless (arguments = peel_redundant_parentheses_from(node.arguments))
-            return unless arguments.first.respond_to?(:method?) && arguments.first.method?(:#{target_method})
+            return unless arguments.first&.call_type?
+            return if arguments.first.arguments.empty? || !arguments.first.method?(:#{target_method})
 
             add_offense(node, message: offense_message(arguments)) do |corrector|
               autocorrect(corrector, node, arguments)

test/rubocop/cop/minitest/assert_match_test.rb

@@ -132,4 +132,24 @@ def test_do_something
       end
     RUBY
   end
+
+  def test_does_not_register_offense_when_using_assert_with_no_arguments_match_call
+    assert_no_offenses(<<~RUBY)
+      class FooTest < Minitest::Test
+        def test_do_something
+          assert(matcher.match)
+        end
+      end
+    RUBY
+  end
+
+  def test_does_not_register_offense_when_using_assert_with_no_arguments_match_safe_navigation_call
+    assert_no_offenses(<<~RUBY)
+      class FooTest < Minitest::Test
+        def test_do_something
+          assert(matcher&.match)
+        end
+      end
+    RUBY
+  end
 end