Mark methods called by ActiveSupport::TestCase.setup as alive

Signed-off-by: Alexandre Terrasa <alexandre.terrasa@shopify.com>

lib/spoom/deadcode/plugins/active_support.rb

@@ -15,6 +15,17 @@ class ActiveSupport < Base
           "before_setup",
           "before_teardown",
         )
+
+        SETUP_AND_TEARDOWN_METHODS = T.let(["setup", "teardown"], T::Array[String])
+
+        sig { override.params(indexer: Indexer, send: Send).void }
+        def on_send(indexer, send)
+          return unless send.recv.nil? && SETUP_AND_TEARDOWN_METHODS.include?(send.name)
+
+          send.each_arg(SyntaxTree::SymbolLiteral) do |arg|
+            indexer.reference_method(indexer.node_string(arg.value), send.node)
+          end
+        end
       end
     end
   end

test/spoom/deadcode/plugins/active_support_test.rb

@@ -0,0 +1,42 @@
+# typed: true
+# frozen_string_literal: true
+
+require "test_with_project"
+require "helpers/deadcode_helper"
+
+module Spoom
+  module Deadcode
+    module Plugins
+      class ActiveSupportTest < TestWithProject
+        include Test::Helpers::DeadcodeHelper
+
+        def test_ignore_minitest_setup_and_teardown_with_symbols
+          @project.write!("test/foo_test.rb", <<~RB)
+            class FooTest
+              setup(:alive1, :alive2)
+              teardown(:alive3)
+
+              def alive1; end
+              def alive2; end
+              def alive3; end
+              def dead; end
+            end
+          RB
+
+          index = index_with_plugins
+          assert_alive(index, "alive1")
+          assert_alive(index, "alive2")
+          assert_alive(index, "alive3")
+          assert_dead(index, "dead")
+        end
+
+        private
+
+        sig { returns(Index) }
+        def index_with_plugins
+          deadcode_index(plugins: [ActiveSupport.new])
+        end
+      end
+    end
+  end
+end