[chore] [exporterhelper] Remove redundant test helper (#8625)

Cut from
#8275

exporter/exporterhelper/queue_sender_test.go

@@ -306,8 +306,6 @@ func TestQueuedRetryPersistentEnabled_shutdown_dataIsRequeued(t *testing.T) {
 	rCfg.InitialInterval = time.Millisecond
 	rCfg.MaxElapsedTime = 0 // retry infinitely so shutdown can be triggered
 
-	req := newMockRequest(context.Background(), 3, errors.New("some error"))
-
 	be, err := newBaseExporter(defaultSettings, "", false, nil, nil, newNoopObsrepSender, WithRetry(rCfg), WithQueue(qCfg))
 	require.NoError(t, err)
 
@@ -320,13 +318,8 @@ func TestQueuedRetryPersistentEnabled_shutdown_dataIsRequeued(t *testing.T) {
 	}
 	be.queueSender.(*queueSender).requeuingEnabled = true
 
-	// replace nextSender inside retrySender to always return error so it doesn't exit send loop
-	be.retrySender.setNextSender(&errorRequestSender{
-		errToReturn: errors.New("some error"),
-	})
-
 	// Invoke queuedRetrySender so the producer will put the item for consumer to poll
-	require.NoError(t, be.send(req))
+	require.NoError(t, be.send(newErrorRequest(context.Background())))
 
 	// first wait for the item to be produced to the queue initially
 	assert.Eventually(t, func() bool {

exporter/exporterhelper/retry_sender_test.go

@@ -404,12 +404,3 @@ func (pcq *producerConsumerQueueWithCounter) Produce(item internal.Request) bool
 	pcq.produceCounter.Add(1)
 	return pcq.ProducerConsumerQueue.Produce(item)
 }
-
-type errorRequestSender struct {
-	baseRequestSender
-	errToReturn error
-}
-
-func (rs *errorRequestSender) send(_ internal.Request) error {
-	return rs.errToReturn
-}