fix: do not exit non-zero on inconclusive bisect

ruby/lib/minitest/queue/runner.rb

@@ -254,7 +254,9 @@ def bisect_command
           step(yellow("The failing test was the first test in the test order so there is nothing to bisect."))
           File.write('log/test_order.log', "")
           File.write('log/bisect_test_details.log', "")
-          exit! 1
+          # Bisect ran successfully; there is simply nothing to bisect against.
+          # Reserve non-zero exits for cases where the bisect could not run (see failing_test_present? above).
+          exit! 0
         end
 
         failing_order = queue.candidates
@@ -263,7 +265,10 @@ def bisect_command
           step(yellow("The bisection was inconclusive, there might not be any leaky test here."))
           File.write('log/test_order.log', "")
           File.write('log/bisect_test_details.log', "")
-          exit! 1
+          # Bisect ran successfully; the failure did not reproduce on the narrowed-down order.
+          # This is the expected outcome for genuinely flaky tests (timing/async) rather than order-dependent ones.
+          # Reserve non-zero exits for cases where the bisect could not run.
+          exit! 0
         else
           step(green('The following command should reproduce the leak on your machine:'), collapsed: false)
           command = %w(bundle exec minitest-queue --queue - run)

ruby/test/integration/minitest_bisect_test.rb

@@ -11,10 +11,12 @@ def setup
     end
 
     def test_bisect
+      result = nil
       out, err = capture_subprocess_io do
-        run_bisect('log/leaky_test_order.log', 'LeakyTest#test_sensible_to_leak')
+        result = run_bisect('log/leaky_test_order.log', 'LeakyTest#test_sensible_to_leak')
       end
 
+      assert_equal true, result, "bisect should exit 0 when a leaky test is identified"
       assert_empty filter_deprecation_warnings(err)
       expected_output = strip_heredoc <<-EOS
         --- Testing the failing test in isolation
@@ -101,10 +103,12 @@ def test_bisect
     end
 
     def test_inconclusive
+      result = nil
       out, err = capture_subprocess_io do
-        run_bisect('log/unconclusive_test_order.log', 'LeakyTest#test_sensible_to_leak')
+        result = run_bisect('log/unconclusive_test_order.log', 'LeakyTest#test_sensible_to_leak')
       end
 
+      assert_equal true, result, "inconclusive bisect should exit 0; it ran successfully and reported a valid diagnostic outcome"
       assert_empty filter_deprecation_warnings(err)
       expected_output = strip_heredoc <<-EOS
         --- Testing the failing test in isolation
@@ -178,10 +182,12 @@ def test_inconclusive
     end
 
     def test_failing_test_is_the_first_entry_in_the_test_order
+      result = nil
       out, err = capture_subprocess_io do
-        run_bisect('log/unconclusive_test_order.log', 'LeakyTest#test_useless_0')
+        result = run_bisect('log/unconclusive_test_order.log', 'LeakyTest#test_useless_0')
       end
 
+      assert_equal true, result, "should exit 0 when there is nothing to bisect; the run completed normally"
       assert_empty filter_deprecation_warnings(err)
       expected_output = strip_heredoc <<-EOS
         --- Testing the failing test in isolation
@@ -193,10 +199,12 @@ def test_failing_test_is_the_first_entry_in_the_test_order
     end
 
     def test_broken_tests_which_are_not_evaluated_are_ignored
+      result = nil
       out, err = capture_subprocess_io do
-        run_bisect('log/leaky_with_broken_test_order.log', 'LeakyTest#test_sensible_to_leak')
+        result = run_bisect('log/leaky_with_broken_test_order.log', 'LeakyTest#test_sensible_to_leak')
       end
 
+      assert_equal true, result, "inconclusive bisect should exit 0 even when broken tests are skipped along the way"
       assert_empty filter_deprecation_warnings(err)
       expected_output = strip_heredoc <<-EOS
         --- Testing the failing test in isolation
@@ -270,10 +278,12 @@ def test_broken_tests_which_are_not_evaluated_are_ignored
     end
 
     def test_broken
+      result = nil
       out, err = capture_subprocess_io do
-        run_bisect('log/broken_test_order.log', 'LeakyTest#test_broken_test')
+        result = run_bisect('log/broken_test_order.log', 'LeakyTest#test_broken_test')
       end
 
+      assert_equal true, result, "should exit 0 when the failing test fails in isolation; bisect ran and produced a useful diagnostic"
       assert_empty filter_deprecation_warnings(err)
       expected_output = strip_heredoc <<-EOS
         --- Testing the failing test in isolation
@@ -287,10 +297,12 @@ def test_broken
     end
 
     def test_failing_test_is_not_present
+      result = nil
       out, err = capture_subprocess_io do
-        run_bisect('log/leaky_test_order.log', 'LeakyTestDoesNotExist#test_sensible_to_leak')
+        result = run_bisect('log/leaky_test_order.log', 'LeakyTestDoesNotExist#test_sensible_to_leak')
       end
 
+      assert_equal false, result, "should exit non-zero when the failing test cannot be found; the run could not actually execute"
       assert_empty filter_deprecation_warnings(err)
       expected_output = strip_heredoc <<-EOS
         --- Testing the failing test in isolation