Test case that fails due to NullPointerException

google-http-client-jackson2/pom.xml

@@ -85,5 +85,22 @@
       <artifactId>guava</artifactId>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>org.mockito</groupId>
+      <artifactId>mockito-all</artifactId>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>com.google.api-client</groupId>
+      <artifactId>google-api-client</artifactId>
+      <version>1.31.1</version>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>com.google.apis</groupId>
+      <artifactId>google-api-services-storage</artifactId>
+      <version>v1-rev20210127-1.31.0</version>
+      <scope>test</scope>
+    </dependency>
   </dependencies>
 </project>

google-http-client-jackson2/src/test/java/com/google/api/client/json/jackson2/BatchTest.java

@@ -0,0 +1,201 @@
+/*
+ *
+ *  * Copyright 2021 Google LLC.
+ *  *
+ *  * Licensed under the Apache License, Version 2.0 (the "License");
+ *  * you may not use this file except in compliance with the License.
+ *  * You may obtain a copy of the License at
+ *  *
+ *  *     http://www.apache.org/licenses/LICENSE-2.0
+ *  *
+ *  * Unless required by applicable law or agreed to in writing, software
+ *  * distributed under the License is distributed on an "AS IS" BASIS,
+ *  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  * See the License for the specific language governing permissions and
+ *  * limitations under the License.
+ *
+ *
+ */
+
+package com.google.api.client.json.jackson2;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.fail;
+import static org.mockito.Mockito.when;
+
+import com.google.api.client.googleapis.batch.BatchRequest;
+import com.google.api.client.googleapis.batch.json.JsonBatchCallback;
+import com.google.api.client.googleapis.json.GoogleJsonError;
+import com.google.api.client.http.HttpHeaders;
+import com.google.api.client.http.HttpRequest;
+import com.google.api.client.http.HttpRequestInitializer;
+import com.google.api.client.http.HttpResponse;
+import com.google.api.client.http.HttpResponseException;
+import com.google.api.client.http.HttpUnsuccessfulResponseHandler;
+import com.google.api.client.http.LowLevelHttpResponse;
+import com.google.api.client.json.Json;
+import com.google.api.client.testing.http.MockHttpTransport;
+import com.google.api.client.testing.http.MockLowLevelHttpRequest;
+import com.google.api.services.storage.Storage;
+import com.google.api.services.storage.model.StorageObject;
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.charset.StandardCharsets;
+import org.junit.Test;
+import org.mockito.Mockito;
+
+/**
+ * Test to verify https://github.com/apache/beam/pull/14527#discussion_r613980011.
+ *
+ * <p>I wanted to put this in google-http-client module, but google-http-client-json dependency
+ * would create a dependency cycle. Therefore I place this in this class.
+ */
+public class BatchTest {
+
+  private static InputStream toStream(String content) throws IOException {
+    return new ByteArrayInputStream(content.getBytes(StandardCharsets.UTF_8));
+  }
+
+  // This test case tries to simulate Beam's GcsUtilTest, where it reads the content of failed
+  // response and throws corresponding IOException after a retry on status code 429.
+  // https://github.com/apache/beam/pull/14527/files#diff-1b8fce5e4444d5c3e99bd0564a8848f9e6d232550efb67902bfeb5ac53819836R505
+  @Test
+  public void testErrorContentReadRetry() throws IOException {
+    String contentBoundary = "batch_foobarbaz";
+    String contentBoundaryLine = "--" + contentBoundary;
+    String endOfContentBoundaryLine = "--" + contentBoundary + "--";
+    String content =
+        contentBoundaryLine
+            + "\n"
+            + "Content-Type: application/http\n"
+            + "\n"
+            + "HTTP/1.1 404 Not Found\n"
+            + "Content-Length: -1\n"
+            + "\n"
+            + "{\"error\":{\"code\":404}}"
+            + "\n"
+            + "\n"
+            + endOfContentBoundaryLine
+            + "\n";
+    final LowLevelHttpResponse mockResponse = Mockito.mock(LowLevelHttpResponse.class);
+    when(mockResponse.getContentType())
+        .thenReturn("text/plain;  charset=UTF-8")
+        .thenReturn("multipart/mixed; boundary=" + contentBoundary);
+
+    // 429: Too many requests, then 200: OK.
+    final int statusCode429_TooManyRequest = 429;
+    when(mockResponse.getStatusCode()).thenReturn(statusCode429_TooManyRequest, 200);
+    when(mockResponse.getContent()).thenReturn(toStream("rateLimitExceeded"), toStream(content));
+
+    MockHttpTransport mockTransport =
+        new MockHttpTransport.Builder()
+            .setLowLevelHttpRequest(
+                new MockLowLevelHttpRequest() {
+                  @Override
+                  public LowLevelHttpResponse execute() throws IOException {
+                    return mockResponse;
+                  }
+                })
+            .build();
+
+    HttpRequestInitializer httpRequestInitializer =
+        new HttpRequestInitializer() {
+          @Override
+          public void initialize(HttpRequest request) throws IOException {
+            request.setUnsuccessfulResponseHandler(
+                new HttpUnsuccessfulResponseHandler() {
+                  @Override
+                  public boolean handleResponse(
+                      HttpRequest request, HttpResponse response, boolean supportsRetry)
+                      throws IOException {
+                    // true to retry
+                    boolean willRetry = response.getStatusCode() == statusCode429_TooManyRequest;
+                    return willRetry;
+                  }
+                });
+          }
+        };
+    Storage storageClient =
+        new Storage(mockTransport, JacksonFactory.getDefaultInstance(), httpRequestInitializer);
+    BatchRequest batch = storageClient.batch(httpRequestInitializer);
+
+    Storage.Objects.Get getRequest = storageClient.objects().get("testbucket", "testobject");
+
+    final GoogleJsonError[] capturedGoogleJsonError = new GoogleJsonError[1];
+    getRequest.queue(
+        batch,
+        new JsonBatchCallback<StorageObject>() {
+          @Override
+          public void onSuccess(StorageObject response, HttpHeaders httpHeaders)
+              throws IOException {
+            System.out.println("Got response: " + response);
+          }
+
+          @Override
+          public void onFailure(GoogleJsonError e, HttpHeaders httpHeaders) throws IOException {
+            System.out.println("Got error: " + e);
+            capturedGoogleJsonError[0] = e;
+          }
+        });
+
+    batch.execute();
+    assertNotNull(capturedGoogleJsonError[0]);
+
+    // From {"error":{"code":404}}
+    assertEquals(404, capturedGoogleJsonError[0].getCode());
+  }
+
+  @Test
+  public void testErrorContentRead_NoRetry() throws IOException {
+    final LowLevelHttpResponse mockResponse = Mockito.mock(LowLevelHttpResponse.class);
+    when(mockResponse.getContentType()).thenReturn(Json.MEDIA_TYPE);
+
+    // 429: Too many requests
+    when(mockResponse.getStatusCode()).thenReturn(429);
+
+    // This value is dummy
+    String contentInError = "{\"error\":{\"code\":429}}";
+    when(mockResponse.getContent()).thenReturn(toStream(contentInError));
+
+    MockHttpTransport mockTransport =
+        new MockHttpTransport.Builder()
+            .setLowLevelHttpRequest(
+                new MockLowLevelHttpRequest() {
+                  @Override
+                  public LowLevelHttpResponse execute() throws IOException {
+                    return mockResponse;
+                  }
+                })
+            .build();
+
+    // No retry
+    Storage storageClient = new Storage(mockTransport, JacksonFactory.getDefaultInstance(), null);
+    BatchRequest batch = storageClient.batch();
+
+    Storage.Objects.Get getRequest = storageClient.objects().get("testbucket", "testobject");
+
+    getRequest.queue(
+        batch,
+        new JsonBatchCallback<StorageObject>() {
+          @Override
+          public void onSuccess(StorageObject response, HttpHeaders httpHeaders)
+              throws IOException {
+            System.out.println("Got response: " + response);
+          }
+
+          @Override
+          public void onFailure(GoogleJsonError e, HttpHeaders httpHeaders) throws IOException {
+            System.out.println("Got error: " + e);
+          }
+        });
+
+    try {
+      batch.execute();
+      fail("batch.execute should throw an exception");
+    } catch (HttpResponseException ex) {
+      assertEquals(contentInError, ex.getContent());
+    }
+  }
+}