Merge pull request #579 from Shopify/at-deadcode-minitest

Improve deadcode plugin for Minitest

lib/spoom/deadcode/plugins/minitest.rb

@@ -7,21 +7,39 @@ module Plugins
       class Minitest < Base
         extend T::Sig
 
-        ignore_classes_named(/Test$/)
-
-        ignore_methods_named(
-          "after_all",
-          "around",
-          "around_all",
-          "before_all",
-          "setup",
-          "teardown",
+        ignore_classes_inheriting_from("Minitest::Test")
+
+        MINITEST_METHODS = T.let(
+          Set.new([
+            "after_all",
+            "around",
+            "around_all",
+            "before_all",
+            "setup",
+            "teardown",
+          ]),
+          T::Set[String],
         )
 
         sig { override.params(definition: Model::Method).void }
         def on_define_method(definition)
-          file = definition.location.file
-          @index.ignore(definition) if file.match?(%r{test/.*test\.rb$}) && definition.name.match?(/^test_/)
+          return unless definition.name.start_with?("test_") || MINITEST_METHODS.include?(definition.name)
+
+          owner = definition.owner
+          return unless owner.is_a?(Model::Class)
+
+          @index.ignore(definition) if ignored_subclass?(owner)
+        end
+
+        sig { override.params(send: Send).void }
+        def on_send(send)
+          case send.name
+          when "assert_predicate", "refute_predicate"
+            name = send.args[1]&.slice
+            return unless name
+
+            @index.reference_method(name.delete_prefix(":"), send.location)
+          end
         end
       end
     end

test/spoom/deadcode/plugins/minitest_test.rb

@@ -10,30 +10,57 @@ module Plugins
       class MinitestTest < TestWithProject
         include Test::Helpers::DeadcodeHelper
 
-        def test_ignore_minitest_classes_based_on_name
+        def test_ignore_minitest_classes_based_on_superclasses
           @project.write!("foo.rb", <<~RB)
             class C1Test < Minitest::Test; end
           RB
 
           @project.write!("test/foo.rb", <<~RB)
-            class C2Test < SomeTest; end
+            class C2Test < ::Minitest::Test; end
           RB
 
           @project.write!("test/foo_test.rb", <<~RB)
-            class C3Test; end
-            class C4; end
+            class C3Test < ::Minitest::Test; end
+            class C4Test < C3Test; end
+            class C5Test; end
           RB
 
           index = index_with_plugins
           assert_ignored(index, "C1Test")
           assert_ignored(index, "C2Test")
-          assert_ignored(index, "C3Test")
-          refute_ignored(index, "C4")
+          assert_alive(index, "C3Test")
+          assert_ignored(index, "C4Test")
+          refute_ignored(index, "C5Test")
         end
 
-        def test_ignore_minitest_methods
+        def test_does_not_ignore_minitest_methods_if_not_in_minitest_test_subclass
           @project.write!("test/foo_test.rb", <<~RB)
-            class FooTest
+            class FooTest < Test
+              def after_all; end
+              def around; end
+              def around_all; end
+              def before_all; end
+              def setup; end
+              def teardown; end
+              def test_something; end
+
+              def some_other_test; end
+            end
+          RB
+
+          index = index_with_plugins
+          refute_ignored(index, "after_all")
+          refute_ignored(index, "around")
+          refute_ignored(index, "around_all")
+          refute_ignored(index, "before_all")
+          refute_ignored(index, "setup")
+          refute_ignored(index, "teardown")
+          refute_ignored(index, "test_something")
+        end
+
+        def test_ignore_minitest_methods_if_in_minitest_test_subclass
+          @project.write!("test/foo_test.rb", <<~RB)
+            class FooTest < Minitest::Test
               def after_all; end
               def around; end
               def around_all; end
@@ -57,6 +84,26 @@ def some_other_test; end
           refute_ignored(index, "some_other_test")
         end
 
+        def test_ignore_minitest_predicates
+          @project.write!("test/foo_test.rb", <<~RB)
+            class FooTest
+              def alive1; end
+              def alive2; end
+              def dead; end
+
+              def test_something
+                assert_predicate(foo, :alive1)
+                refute_predicate(foo, :alive2)
+              end
+            end
+          RB
+
+          index = index_with_plugins
+          assert_alive(index, "alive1")
+          assert_alive(index, "alive2")
+          assert_dead(index, "dead")
+        end
+
         private
 
         sig { returns(Deadcode::Index) }