Fix AbstractSimpleTransportTestCase#testFailToSend (#75211)

Adjust test after changing how exception is wrapped.

Author: iverase

test/framework/src/main/java/org/elasticsearch/transport/AbstractSimpleTransportTestCase.java

@@ -2708,15 +2708,22 @@ public void onConnectionClosed(Transport.Connection connection) {
         }
     }
 
+    public void testFailToSendTransportException() throws InterruptedException {
+        TransportException exception = doFailToSend(new TransportException("fail to send"));
+        assertThat(exception.getMessage(), equalTo("fail to send"));
+        assertThat(exception.getCause(), nullValue());
+    }
+
+    public void testFailToSendIllegalStateException() throws InterruptedException {
+        TransportException exception = doFailToSend(new IllegalStateException("fail to send"));
+        assertThat(exception, instanceOf(SendRequestTransportException.class));
+        assertThat(exception.getMessage(), containsString("fail-to-send-action"));
+        assertThat(exception.getCause(), instanceOf(IllegalStateException.class));
+        assertThat(exception.getCause().getMessage(), equalTo("fail to send"));
+    }
+
     // test that the response handler is invoked on a failure to send
-    @AwaitsFix(bugUrl = "https://github.com/elastic/elasticsearch/issues/75209")
-    public void testFailToSend() throws InterruptedException {
-        final RuntimeException failToSendException;
-        if (randomBoolean()) {
-            failToSendException = new IllegalStateException("fail to send");
-        } else {
-            failToSendException = new TransportException("fail to send");
-        }
+    private TransportException doFailToSend(RuntimeException failToSendException) throws InterruptedException {
         final TransportInterceptor interceptor = new TransportInterceptor() {
             @Override
             public AsyncSender interceptSender(final AsyncSender sender) {
@@ -2752,7 +2759,7 @@ public void onResponse(final Void v) {
                     public void onFailure(final Exception e) {
                         fail(e.getMessage());
                     }
-            });
+                });
             latch.await();
             final AtomicReference<TransportException> te = new AtomicReference<>();
             final Transport.Connection connection = serviceC.getConnection(nodeA);
@@ -2773,17 +2780,8 @@ public void handleException(final TransportException exp) {
                     }
                 });
             assertThat(te.get(), not(nullValue()));
-
-            if (failToSendException instanceof IllegalStateException) {
-                assertThat(te.get().getMessage(), equalTo("failure to send"));
-                assertThat(te.get().getCause(), instanceOf(IllegalStateException.class));
-                assertThat(te.get().getCause().getMessage(), equalTo("fail to send"));
-            } else {
-                assertThat(te.get().getMessage(), equalTo("fail to send"));
-                assertThat(te.get().getCause(), nullValue());
-            }
+            return te.get();
         }
-
     }
 
     private void closeConnectionChannel(Transport.Connection connection) {