Add test for checking chunk.commit isn't called against closed one

Signed-off-by: Takuro Ashie <[email protected]>

test/plugin/test_buffer.rb

@@ -850,6 +850,35 @@ def create_chunk_es(metadata, es)
     test '#compress returns :text' do
       assert_equal :text, @p.compress
     end
+
+    # https://github.com/fluent/fluentd/issues/3089#issuecomment-1811839198
+    test "closed chunk should not be committed" do
+      assert_equal 8 * 1024 * 1024, @p.chunk_limit_size
+      assert_equal 0.95, @p.chunk_full_threshold
+
+      stub.proxy(@p).generate_chunk(anything) do |chunk|
+        stub.proxy(chunk).commit do |result|
+          assert_false(chunk.closed?)
+          result
+        end
+        stub.proxy(chunk).rollback do |result|
+          assert_false(chunk.closed?)
+          result
+        end
+        chunk
+      end
+
+      m = @p.metadata(timekey: Time.parse('2016-04-11 16:40:00 +0000').to_i)
+      row = "x" * 1024 * 1024 * 8
+      small_row = "x" * 1024 * 400
+      @p.write({m => [small_row] * 40 + [row] + [small_row] * 1})
+
+      assert_equal [@dm0, @dm1, @dm1, m, m, m], @p.queue.map(&:metadata)
+      assert_equal [@dm2, @dm3, m], @p.stage.keys
+      assert_equal 1, @p.stage[m].append_count
+      assert_equal 1024 * 400, @p.stage[m].bytesize
+      assert_equal 1, @p.queue.last.append_count
+    end
   end
 
   sub_test_case 'standard format with configuration for test with lower chunk limit size' do