[HUDI-1476] Introduce unit test infra for java client (#2478)

hudi-client/hudi-client-common/src/test/java/org/apache/hudi/testutils/Assertions.java

@@ -0,0 +1,41 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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 org.apache.hudi.testutils;
+
+import org.apache.hudi.client.WriteStatus;
+
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.assertAll;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+
+/**
+ * Commonly used assertion functions.
+ */
+public class Assertions {
+
+  /**
+   * Assert no failures in writing hoodie files.
+   */
+  public static void assertNoWriteErrors(List<WriteStatus> statuses) {
+    assertAll(statuses.stream().map(status -> () ->
+        assertFalse(status.hasErrors(), "Errors found in write of " + status.getFileId())));
+  }
+}

hudi-client/hudi-client-common/src/test/java/org/apache/hudi/testutils/MetadataMergeWriteStatus.java

@@ -0,0 +1,85 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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 org.apache.hudi.testutils;
+
+import org.apache.hudi.client.WriteStatus;
+import org.apache.hudi.common.model.HoodieRecord;
+import org.apache.hudi.common.util.Option;
+
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Map.Entry;
+
+/**
+ * A custom {@link WriteStatus} that merges passed metadata key value map to {@code WriteStatus.markSuccess()} and
+ * {@code WriteStatus.markFailure()}.
+ */
+public class MetadataMergeWriteStatus extends WriteStatus {
+
+  private Map<String, String> mergedMetadataMap = new HashMap<>();
+
+  public MetadataMergeWriteStatus(Boolean trackSuccessRecords, Double failureFraction) {
+    super(trackSuccessRecords, failureFraction);
+  }
+
+  public static Map<String, String> mergeMetadataForWriteStatuses(List<WriteStatus> writeStatuses) {
+    Map<String, String> allWriteStatusMergedMetadataMap = new HashMap<>();
+    for (WriteStatus writeStatus : writeStatuses) {
+      MetadataMergeWriteStatus.mergeMetadataMaps(((MetadataMergeWriteStatus) writeStatus).getMergedMetadataMap(),
+          allWriteStatusMergedMetadataMap);
+    }
+    return allWriteStatusMergedMetadataMap;
+  }
+
+  private static void mergeMetadataMaps(Map<String, String> mergeFromMap, Map<String, String> mergeToMap) {
+    for (Entry<String, String> entry : mergeFromMap.entrySet()) {
+      String key = entry.getKey();
+      if (!mergeToMap.containsKey(key)) {
+        mergeToMap.put(key, "0");
+      }
+      mergeToMap.put(key, addStrsAsInt(entry.getValue(), mergeToMap.get(key)));
+    }
+  }
+
+  private static String addStrsAsInt(String a, String b) {
+    return String.valueOf(Integer.parseInt(a) + Integer.parseInt(b));
+  }
+
+  @Override
+  public void markSuccess(HoodieRecord record, Option<Map<String, String>> recordMetadata) {
+    super.markSuccess(record, recordMetadata);
+    if (recordMetadata.isPresent()) {
+      mergeMetadataMaps(recordMetadata.get(), mergedMetadataMap);
+    }
+  }
+
+  @Override
+  public void markFailure(HoodieRecord record, Throwable t, Option<Map<String, String>> recordMetadata) {
+    super.markFailure(record, t, recordMetadata);
+    if (recordMetadata.isPresent()) {
+      mergeMetadataMaps(recordMetadata.get(), mergedMetadataMap);
+    }
+  }
+
+  private Map<String, String> getMergedMetadataMap() {
+    return mergedMetadataMap;
+  }
+}