Check for assertion method receiver - fixes #321

[MatzFan]

Counting assertions based on a string prefix of "assert_" or "refute_" is replaced by a symbol comparison against the 38 Minitest assertion methods.

[Earlopain]

This is not the best solution. It will ignore all custom assertions the user may have written themselves, and test methods provided by gems like rails.

I think it would be better to instead only look at methods that have no receiver.

[MatzFan]

@Earlopain

It will ignore all custom assertions the user may have written themselves, and test methods provided by gems like rails.

Apologies, I didn't see that tested for anywhere.

I think it would be better to instead only look at methods that have no receiver.

Or where the receiver is not a kind_of Minitest::Test?

[Earlopain]

Apologies, I didn't see that tested for anywhere.

I guess the assert_something call you changed could be counted as that but yes, it isn't very explicit in the test suite yet. Let's just add a testcase for custom assertion methods with this PR.

Or where the receiver is not a kind_of Minitest::Test?

Perhaps, but not decidable by rubocop. It can't tell if MyCustomTestCase or AcitveSupport::TestCase inherit from Minitest::Test. Just no receiver seems fine, unless you see a problem with that yourself.

---

Please add a changelog entry for this, and write a meaningful commit message starting with [Fix #321]. Thanks!

[MatzFan]

Will take a 👀

[koic]

Can you refactor to the following and rebase with the latest master branch?

diff --git a/lib/rubocop/cop/mixin/minitest_exploration_helpers.rb b/lib/rubocop/cop/mixin/minitest_exploration_helpers.rb
index 4bb7382..ceb1971 100644
--- a/lib/rubocop/cop/mixin/minitest_exploration_helpers.rb
+++ b/lib/rubocop/cop/mixin/minitest_exploration_helpers.rb
@@ -99,19 +99,20 @@ module RuboCop
         end
       end

-      # rubocop:disable Metrics/CyclomaticComplexity, Metrics/PerceivedComplexity, Metrics/AbcSize
+      # rubocop:disable Metrics/AbcSize, Metrics/CyclomaticComplexity, Metrics/PerceivedComplexity
       def assertion_method?(node)
         return false unless node
+        return false if node.receiver
         return assertion_method?(node.expression) if node.assignment? && node.respond_to?(:expression)
         return false if !node.send_type? && !node.block_type? && !node.numblock_type?

         ASSERTION_PREFIXES.any? do |prefix|
           method_name = node.method_name

-          (method_name.start_with?(prefix) && !node.receiver) || node.method?(:flunk)
+          method_name.start_with?(prefix) || node.method?(:flunk)
         end
       end
-      # rubocop:enable Metrics/CyclomaticComplexity, Metrics/PerceivedComplexity, Metrics/AbcSize
+      # rubocop:enable Metrics/AbcSize, Metrics/CyclomaticComplexity, Metrics/PerceivedComplexity

       def lifecycle_hook_method?(node)
         node.def_type? && LIFECYCLE_HOOK_METHODS.include?(node.method_name)