Fix flaky test_latest_gc_info_need_major_by

It's possible for a GC to run between the calls of GC.latest_gc_info,
which would cause the test to fail. We can disable GC so that GC only
triggers manually.

1 files changed, 11 insertions, 9 deletions

diff --git a/test/ruby/test_gc.rb b/test/ruby/test_gc.rb
index 9029f2bda8..43444fe8e7 100644
--- a/test/ruby/test_gc.rb
+++ b/test/ruby/test_gc.rb
@@ -374,15 +374,17 @@ class TestGc < Test::Unit::TestCase
       objects.append(100.times.map { '*' })
     end
 
-    # We need to ensure that no GC gets ran before the call to GC.start since
-    # it would trigger a major GC. Assertions could allocate objects and
-    # trigger a GC so we don't run assertions until we perform the major GC.
-    need_major_by = GC.latest_gc_info(:need_major_by)
-    GC.start(full_mark: false) # should be upgraded to major
-    major_by = GC.latest_gc_info(:major_by)
-
-    assert_not_nil(need_major_by)
-    assert_not_nil(major_by)
+    EnvUtil.without_gc do
+      # We need to ensure that no GC gets ran before the call to GC.start since
+      # it would trigger a major GC. Assertions could allocate objects and
+      # trigger a GC so we don't run assertions until we perform the major GC.
+      need_major_by = GC.latest_gc_info(:need_major_by)
+      GC.start(full_mark: false) # should be upgraded to major
+      major_by = GC.latest_gc_info(:major_by)
+
+      assert_not_nil(need_major_by)
+      assert_not_nil(major_by)
+    end
   end
 
   def test_latest_gc_info_weak_references_count