test(opensearchutil): close the clients the bulk indexer tests supply

Thirteen cases in bulk_indexer_internal_test.go build an opensearchapi
client and hand it to BulkIndexerConfig.Client. A supplied client is not
owned by the indexer, so implicitClient stays false and BulkIndexer.Close
leaves it open, exactly as TestBulkIndexerOwnClientFlag asserts. Each one
left its transport polling node stats and cluster health for the rest of
the test binary.

Register the same t.Cleanup close used elsewhere on this branch. The one
remaining unclosed client in the file is deliberate: that case forces
implicitClient to true so the indexer owns it, then asserts the close
happened.

Signed-off-by: Ryan Yuan <ryan.yuan@crowdstrike.com>

Author: ryanyuan

opensearchutil/bulk_indexer_internal_test.go

@@ -299,6 +299,7 @@ func TestBulkIndexerLifecycle(t *testing.T) {
 						return &http.Response{Body: io.NopCloser(bytes.NewBuffer(bodyContent))}, nil
 					},
 				}}})
+				t.Cleanup(func() { _ = client.Close() })
 
 				cfg := BulkIndexerConfig{
 					NumWorkers:    1,
@@ -356,6 +357,7 @@ func TestBulkIndexerLifecycle(t *testing.T) {
 						}, nil
 					},
 				}}})
+				t.Cleanup(func() { _ = client.Close() })
 
 				cfg := BulkIndexerConfig{
 					NumWorkers:    1,
@@ -443,6 +445,7 @@ func TestBulkIndexerLifecycle(t *testing.T) {
 					cfg.Client.Logger = &opensearchtransport.ColorLogger{Output: os.Stdout}
 				}
 				client, _ := opensearchapi.NewClient(cfg)
+				t.Cleanup(func() { _ = client.Close() })
 
 				biCfg := BulkIndexerConfig{NumWorkers: 1, FlushBytes: 50, Client: client}
 				if testutil.IsDebugEnabled(t) {
@@ -496,6 +499,7 @@ func TestBulkIndexerContext(t *testing.T) {
 			run: func(t *testing.T) {
 				t.Helper()
 				client, _ := opensearchapi.NewClient(opensearchapi.Config{Client: opensearch.Config{Transport: &mockTransport{}}})
+				t.Cleanup(func() { _ = client.Close() })
 				bi, _ := NewBulkIndexer(BulkIndexerConfig{NumWorkers: 1, Client: client})
 				ctx, cancel := context.WithTimeout(context.Background(), time.Nanosecond)
 				defer cancel()
@@ -522,6 +526,7 @@ func TestBulkIndexerContext(t *testing.T) {
 			run: func(t *testing.T) {
 				t.Helper()
 				client, _ := opensearchapi.NewClient(opensearchapi.Config{Client: opensearch.Config{Transport: &mockTransport{}}})
+				t.Cleanup(func() { _ = client.Close() })
 				bi, _ := NewBulkIndexer(BulkIndexerConfig{NumWorkers: 1, Client: client})
 
 				ctx, cancel := context.WithCancel(context.Background())
@@ -555,6 +560,7 @@ func TestBulkIndexerContext(t *testing.T) {
 			run: func(t *testing.T) {
 				t.Helper()
 				client, _ := opensearchapi.NewClient(opensearchapi.Config{Client: opensearch.Config{Transport: &mockTransport{}}})
+				t.Cleanup(func() { _ = client.Close() })
 				bi, _ := NewBulkIndexer(BulkIndexerConfig{
 					NumWorkers: 1,
 					FlushBytes: 1,
@@ -579,6 +585,7 @@ func TestBulkIndexerContext(t *testing.T) {
 				// forever signaling a flusher that already left. Regression for
 				// the unbuffered done-channel deadlock.
 				client, _ := opensearchapi.NewClient(opensearchapi.Config{Client: opensearch.Config{Transport: &mockTransport{}}})
+				t.Cleanup(func() { _ = client.Close() })
 				ctx, cancel := context.WithCancel(t.Context())
 				bi, err := NewBulkIndexer(BulkIndexerConfig{
 					NumWorkers: 1,
@@ -644,6 +651,7 @@ func TestBulkIndexerCallbacks(t *testing.T) {
 					}
 				}
 				client, _ := opensearchapi.NewClient(config)
+				t.Cleanup(func() { _ = client.Close() })
 
 				var (
 					indexerError error
@@ -703,6 +711,7 @@ func TestBulkIndexerCallbacks(t *testing.T) {
 						},
 					},
 				)
+				t.Cleanup(func() { _ = client.Close() })
 
 				cfg := BulkIndexerConfig{NumWorkers: 1, Client: client}
 				if testutil.IsDebugEnabled(t) {
@@ -793,6 +802,7 @@ func TestBulkIndexerCallbacks(t *testing.T) {
 						}, nil
 					},
 				}}})
+				t.Cleanup(func() { _ = client.Close() })
 				flushIndex := testutil.MustUniqueString(t, "test-flush")
 
 				var flushEndCalled atomic.Bool
@@ -847,6 +857,7 @@ func TestBulkIndexerCallbacks(t *testing.T) {
 						},
 					},
 				})
+				t.Cleanup(func() { _ = client.Close() })
 
 				bi, _ := NewBulkIndexer(BulkIndexerConfig{
 					NumWorkers: 1,
@@ -933,6 +944,7 @@ func TestBulkIndexerCallbacks(t *testing.T) {
 						},
 					},
 				)
+				t.Cleanup(func() { _ = client.Close() })
 
 				bi, _ := NewBulkIndexer(BulkIndexerConfig{NumWorkers: 1, Client: client})
 
@@ -984,6 +996,7 @@ func TestBulkIndexerCallbacks(t *testing.T) {
 						},
 					},
 				})
+				t.Cleanup(func() { _ = client.Close() })
 
 				bi, _ := NewBulkIndexer(BulkIndexerConfig{NumWorkers: 1, Client: client})