Add unit test to ensure we unwrap CompletionExceptions.

Really just making the coverage checker happy.

Author: SamBarker

kubernetes-client-api/src/main/java/io/fabric8/kubernetes/client/http/StandardHttpClient.java

@@ -177,26 +177,31 @@ private <V> CompletableFuture<V> retryWithExponentialBackoff(
               }
             }
           } else {
-            final Throwable finalThrowable;
-            if (throwable instanceof CompletionException) {
-              finalThrowable = throwable.getCause();
-            } else {
-              finalThrowable = throwable;
-            }
-            builder.interceptors.forEach((s, interceptor) -> interceptor.afterConnectionFailure(request, finalThrowable));
-            if (finalThrowable instanceof IOException) {
+            final Throwable actualCause = unwrapCompletionException(throwable);
+            builder.interceptors.forEach((s, interceptor) -> interceptor.afterConnectionFailure(request, actualCause));
+            if (actualCause instanceof IOException) {
               // TODO: may not be specific enough - incorrect ssl settings for example will get caught here
               LOG.debug(
                   String.format("HTTP operation on url: %s should be retried after %d millis because of IOException",
                       uri, retryInterval),
-                  finalThrowable);
+                  actualCause);
               return true;
             }
           }
           return false;
         });
   }
 
+  static Throwable unwrapCompletionException(Throwable throwable) {
+    final Throwable actualCause;
+    if (throwable instanceof CompletionException) {
+      actualCause = throwable.getCause();
+    } else {
+      actualCause = throwable;
+    }
+    return actualCause;
+  }
+
   static long retryAfterMillis(HttpResponse<?> httpResponse) {
     String retryAfter = httpResponse.header(StandardHttpHeaders.RETRY_AFTER);
     if (retryAfter != null) {

kubernetes-client-api/src/test/java/io/fabric8/kubernetes/client/http/StandardHttpClientTest.java

@@ -34,6 +34,7 @@
 import java.util.Collections;
 import java.util.List;
 import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.CompletionException;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
@@ -50,6 +51,7 @@
 
 class StandardHttpClientTest {
 
+  public static final String IO_ERROR_MESSAGE = "IO woopsie";
   private TestStandardHttpClient client;
 
   @BeforeEach
@@ -281,4 +283,25 @@ void testDerivedIsClosed() {
     assertTrue(client.isClosed());
   }
 
+  @Test
+  void shouldUnwrapCompletionException() {
+    // Given
+
+    // When
+    final Throwable throwable = StandardHttpClient.unwrapCompletionException(new CompletionException(new IOException(IO_ERROR_MESSAGE)));
+
+    // Then
+    assertThat(throwable).isInstanceOf(IOException.class).hasMessage(IO_ERROR_MESSAGE);
+  }
+
+  @Test
+  void shouldNotUnwrapOtherExceptions() {
+    // Given
+
+    // When
+    final Throwable throwable = StandardHttpClient.unwrapCompletionException(new IOException(IO_ERROR_MESSAGE));
+
+    // Then
+    assertThat(throwable).isInstanceOf(IOException.class).hasMessage(IO_ERROR_MESSAGE);
+  }
 }