Cleaner JSON for various input sources and formats. (#13064)

* Cleaner JSON for various input sources and formats.

Add JsonInclude to various properties, to avoid population of default
values in serialized JSON.

Also fixes a bug in OrcInputFormat: it was not writing binaryAsString,
so the property would be lost on serde.

* Additonal test cases.

core/src/main/java/org/apache/druid/data/input/impl/CloudObjectInputSource.java

@@ -19,6 +19,7 @@
 
 package org.apache.druid.data.input.impl;
 
+import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.google.common.primitives.Ints;
 import org.apache.commons.io.FilenameUtils;
@@ -83,12 +84,14 @@ public abstract class CloudObjectInputSource extends AbstractInputSource
   }
 
   @JsonProperty
+  @JsonInclude(JsonInclude.Include.NON_NULL)
   public List<URI> getUris()
   {
     return uris;
   }
 
   @JsonProperty
+  @JsonInclude(JsonInclude.Include.NON_NULL)
   public List<URI> getPrefixes()
   {
     return prefixes;
@@ -96,6 +99,7 @@ public abstract class CloudObjectInputSource extends AbstractInputSource
 
   @Nullable
   @JsonProperty
+  @JsonInclude(JsonInclude.Include.NON_NULL)
   public List<CloudObjectLocation> getObjects()
   {
     return objects;
@@ -103,6 +107,7 @@ public abstract class CloudObjectInputSource extends AbstractInputSource
 
   @Nullable
   @JsonProperty
+  @JsonInclude(JsonInclude.Include.NON_NULL)
   public String getFilter()
   {
     return filter;

core/src/main/java/org/apache/druid/data/input/impl/FlatTextInputFormat.java

@@ -19,6 +19,7 @@
 
 package org.apache.druid.data.input.impl;
 
+import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
@@ -92,24 +93,29 @@ public abstract class FlatTextInputFormat implements InputFormat
   }
 
   @JsonProperty
+  @JsonInclude(JsonInclude.Include.NON_EMPTY)
   public List<String> getColumns()
   {
     return columns;
   }
 
+  @Nullable
   @JsonProperty
+  @JsonInclude(JsonInclude.Include.NON_NULL)
   public String getListDelimiter()
   {
     return listDelimiter;
   }
 
   @JsonProperty
+  @JsonInclude(JsonInclude.Include.NON_DEFAULT)
   public boolean isFindColumnsFromHeader()
   {
     return findColumnsFromHeader;
   }
 
   @JsonProperty
+  @JsonInclude(JsonInclude.Include.NON_DEFAULT)
   public int getSkipHeaderRows()
   {
     return skipHeaderRows;

core/src/main/java/org/apache/druid/data/input/impl/HttpInputSource.java

@@ -21,6 +21,7 @@ package org.apache.druid.data.input.impl;
 
 import com.fasterxml.jackson.annotation.JacksonInject;
 import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.google.common.base.Preconditions;
 import org.apache.druid.data.input.AbstractInputSource;
@@ -83,6 +84,7 @@ public class HttpInputSource extends AbstractInputSource implements SplittableIn
 
   @Nullable
   @JsonProperty
+  @JsonInclude(JsonInclude.Include.NON_NULL)
   public String getHttpAuthenticationUsername()
   {
     return httpAuthenticationUsername;
@@ -90,6 +92,7 @@ public class HttpInputSource extends AbstractInputSource implements SplittableIn
 
   @Nullable
   @JsonProperty("httpAuthenticationPassword")
+  @JsonInclude(JsonInclude.Include.NON_NULL)
   public PasswordProvider getHttpAuthenticationPasswordProvider()
   {
     return httpAuthenticationPasswordProvider;

core/src/main/java/org/apache/druid/data/input/impl/JsonInputFormat.java

@@ -20,6 +20,7 @@
 package org.apache.druid.data.input.impl;
 
 import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.core.JsonParser.Feature;
 import com.fasterxml.jackson.databind.ObjectMapper;
@@ -87,12 +88,13 @@ public class JsonInputFormat extends NestedInputFormat
   }
 
   @JsonProperty
+  @JsonInclude(JsonInclude.Include.NON_EMPTY)
   public Map<String, Boolean> getFeatureSpec()
   {
     return featureSpec;
   }
 
-  @JsonProperty
+  @JsonProperty // No @JsonInclude, since default is variable, so we can't assume false is default
   public boolean isKeepNullColumns()
   {
     return keepNullColumns;

core/src/main/java/org/apache/druid/data/input/impl/LocalInputSource.java

@@ -20,6 +20,7 @@
 package org.apache.druid.data.input.impl;
 
 import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Preconditions;
@@ -86,6 +87,7 @@ public class LocalInputSource extends AbstractInputSource implements SplittableI
 
   @Nullable
   @JsonProperty
+  @JsonInclude(JsonInclude.Include.NON_NULL)
   public File getBaseDir()
   {
     return baseDir;
@@ -93,12 +95,14 @@ public class LocalInputSource extends AbstractInputSource implements SplittableI
 
   @Nullable
   @JsonProperty
+  @JsonInclude(JsonInclude.Include.NON_NULL)
   public String getFilter()
   {
     return filter;
   }
 
   @JsonProperty
+  @JsonInclude(JsonInclude.Include.NON_EMPTY)
   public List<File> getFiles()
   {
     return files;

core/src/main/java/org/apache/druid/data/input/impl/NestedInputFormat.java

@@ -19,6 +19,7 @@
 
 package org.apache.druid.data.input.impl;
 
+import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import org.apache.druid.data.input.InputFormat;
 import org.apache.druid.java.util.common.parsers.JSONPathSpec;
@@ -42,6 +43,7 @@ public abstract class NestedInputFormat implements InputFormat
 
   @Nullable
   @JsonProperty("flattenSpec")
+  @JsonInclude(JsonInclude.Include.NON_NULL)
   public JSONPathSpec getFlattenSpec()
   {
     return flattenSpec;

core/src/main/java/org/apache/druid/data/input/impl/RegexInputFormat.java

@@ -21,6 +21,7 @@ package org.apache.druid.data.input.impl;
 
 import com.fasterxml.jackson.annotation.JsonCreator;
 import com.fasterxml.jackson.annotation.JsonIgnore;
+import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.google.common.base.Supplier;
 import com.google.common.base.Suppliers;
@@ -63,6 +64,7 @@ public class RegexInputFormat implements InputFormat
 
   @Nullable
   @JsonProperty
+  @JsonInclude(JsonInclude.Include.NON_NULL)
   public String getListDelimiter()
   {
     return listDelimiter;
@@ -70,6 +72,7 @@ public class RegexInputFormat implements InputFormat
 
   @Nullable
   @JsonProperty
+  @JsonInclude(JsonInclude.Include.NON_NULL)
   public List<String> getColumns()
   {
     return columns;

extensions-core/avro-extensions/src/main/java/org/apache/druid/data/input/avro/AvroOCFInputFormat.java

@@ -21,6 +21,7 @@ package org.apache.druid.data.input.avro;
 
 import com.fasterxml.jackson.annotation.JacksonInject;
 import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import org.apache.avro.Schema;
@@ -79,19 +80,23 @@ public class AvroOCFInputFormat extends NestedInputFormat
     return false;
   }
 
+  @Nullable
   @JsonProperty
+  @JsonInclude(JsonInclude.Include.NON_NULL)
   public Map<String, Object> getSchema()
   {
     return schema;
   }
 
   @JsonProperty
-  public Boolean getBinaryAsString()
+  @JsonInclude(JsonInclude.Include.NON_DEFAULT)
+  public boolean getBinaryAsString()
   {
     return binaryAsString;
   }
 
   @JsonProperty
+  @JsonInclude(JsonInclude.Include.NON_DEFAULT)
   public Boolean isExtractUnionsByType()
   {
     return extractUnionsByType;

extensions-core/orc-extensions/pom.xml

@@ -218,6 +218,11 @@
             <artifactId>junit</artifactId>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>nl.jqno.equalsverifier</groupId>
+            <artifactId>equalsverifier</artifactId>
+            <scope>test</scope>
+        </dependency>
         <dependency>
             <groupId>org.apache.druid</groupId>
             <artifactId>druid-core</artifactId>
@@ -225,6 +230,13 @@
             <type>test-jar</type>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.apache.druid</groupId>
+            <artifactId>druid-processing</artifactId>
+            <version>${project.parent.version}</version>
+            <type>test-jar</type>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
     <profiles>
         <profile>

extensions-core/orc-extensions/src/main/java/org/apache/druid/data/input/orc/OrcInputFormat.java

@@ -21,6 +21,7 @@ package org.apache.druid.data.input.orc;
 
 import com.fasterxml.jackson.annotation.JacksonInject;
 import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import org.apache.druid.data.input.InputEntity;
 import org.apache.druid.data.input.InputEntityReader;
@@ -49,7 +50,7 @@ public class OrcInputFormat extends NestedInputFormat
   )
   {
     super(flattenSpec);
-    this.binaryAsString = binaryAsString == null ? false : binaryAsString;
+    this.binaryAsString = binaryAsString != null && binaryAsString;
     this.conf = conf;
   }
 
@@ -79,6 +80,13 @@ public class OrcInputFormat extends NestedInputFormat
     return false;
   }
 
+  @JsonProperty
+  @JsonInclude(JsonInclude.Include.NON_DEFAULT)
+  public boolean getBinaryAsString()
+  {
+    return binaryAsString;
+  }
+
   @Override
   public InputEntityReader createReader(InputRowSchema inputRowSchema, InputEntity source, File temporaryDirectory)
   {

extensions-core/orc-extensions/src/test/java/org/apache/druid/data/input/orc/OrcInputFormatTest.java

@@ -0,0 +1,79 @@
+/*
+ * 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.druid.data.input.orc;
+
+import com.fasterxml.jackson.databind.InjectableValues;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import nl.jqno.equalsverifier.EqualsVerifier;
+import org.apache.druid.data.input.InputFormat;
+import org.apache.druid.java.util.common.parsers.JSONPathSpec;
+import org.apache.druid.segment.TestHelper;
+import org.apache.hadoop.conf.Configuration;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.util.Collections;
+
+public class OrcInputFormatTest
+{
+  private ObjectMapper mapper;
+
+
+  @Before
+  public void setUp()
+  {
+    mapper =
+        TestHelper.makeJsonMapper()
+                  .registerModules(new OrcExtensionsModule().getJacksonModules())
+                  .setInjectableValues(new InjectableValues.Std().addValue(Configuration.class, null));
+  }
+
+  @Test
+  public void testSerdeDefault() throws Exception
+  {
+    final OrcInputFormat config = new OrcInputFormat(null, null, null);
+
+    Assert.assertEquals(
+        config,
+        mapper.readValue(mapper.writeValueAsString(config), InputFormat.class)
+    );
+  }
+
+  @Test
+  public void testSerdeNonDefault() throws Exception
+  {
+    final OrcInputFormat config = new OrcInputFormat(new JSONPathSpec(true, Collections.emptyList()), true, null);
+
+    Assert.assertEquals(
+        config,
+        mapper.readValue(mapper.writeValueAsString(config), InputFormat.class)
+    );
+  }
+
+  @Test
+  public void testEquals()
+  {
+    EqualsVerifier.forClass(OrcInputFormat.class)
+                  .withPrefabValues(Configuration.class, new Configuration(), new Configuration())
+                  .usingGetClass()
+                  .verify();
+  }
+}

extensions-core/parquet-extensions/src/main/java/org/apache/druid/data/input/parquet/ParquetInputFormat.java

@@ -21,6 +21,7 @@ package org.apache.druid.data.input.parquet;
 
 import com.fasterxml.jackson.annotation.JacksonInject;
 import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import org.apache.druid.data.input.InputEntity;
 import org.apache.druid.data.input.InputEntityReader;
@@ -74,6 +75,7 @@ public class ParquetInputFormat extends NestedInputFormat
   }
 
   @JsonProperty
+  @JsonInclude(JsonInclude.Include.NON_DEFAULT)
   public boolean getBinaryAsString()
   {
     return binaryAsString;

extensions-core/s3-extensions/pom.xml

@@ -168,6 +168,11 @@
       <artifactId>hamcrest-core</artifactId>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>nl.jqno.equalsverifier</groupId>
+      <artifactId>equalsverifier</artifactId>
+      <scope>test</scope>
+    </dependency>
   </dependencies>
 
 </project>

extensions-core/s3-extensions/src/main/java/org/apache/druid/data/input/s3/S3InputSource.java

@@ -30,6 +30,7 @@ import com.amazonaws.services.securitytoken.AWSSecurityTokenService;
 import com.amazonaws.services.securitytoken.AWSSecurityTokenServiceClientBuilder;
 import com.fasterxml.jackson.annotation.JacksonInject;
 import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Preconditions;
@@ -77,7 +78,6 @@ public class S3InputSource extends CloudObjectInputSource
   private final AWSProxyConfig awsProxyConfig;
   private final AWSClientConfig awsClientConfig;
   private final AWSEndpointConfig awsEndpointConfig;
-  private final AWSCredentialsProvider awsCredentialsProvider;
   private int maxRetries;
 
   /**
@@ -104,6 +104,7 @@ public class S3InputSource extends CloudObjectInputSource
       @JacksonInject ServerSideEncryptingAmazonS3 s3Client,
       @JacksonInject ServerSideEncryptingAmazonS3.Builder s3ClientBuilder,
       @JacksonInject S3InputDataConfig inputDataConfig,
+      @JacksonInject AWSCredentialsProvider awsCredentialsProvider,
       @JsonProperty("uris") @Nullable List<URI> uris,
       @JsonProperty("prefixes") @Nullable List<URI> prefixes,
       @JsonProperty("objects") @Nullable List<CloudObjectLocation> objects,
@@ -111,8 +112,7 @@ public class S3InputSource extends CloudObjectInputSource
       @JsonProperty("properties") @Nullable S3InputSourceConfig s3InputSourceConfig,
       @JsonProperty("proxyConfig") @Nullable AWSProxyConfig awsProxyConfig,
       @JsonProperty("endpointConfig") @Nullable AWSEndpointConfig awsEndpointConfig,
-      @JsonProperty("clientConfig") @Nullable AWSClientConfig awsClientConfig,
+      @JsonProperty("clientConfig") @Nullable AWSClientConfig awsClientConfig
-      @JacksonInject AWSCredentialsProvider awsCredentialsProvider
   )
   {
     super(S3StorageDruidModule.SCHEME, uris, prefixes, objects, filter);
@@ -174,11 +174,10 @@ public class S3InputSource extends CloudObjectInputSource
         }
     );
     this.maxRetries = RetryUtils.DEFAULT_MAX_TRIES;
-    this.awsCredentialsProvider = awsCredentialsProvider;
   }
 
   @VisibleForTesting
-  public S3InputSource(
+  S3InputSource(
       ServerSideEncryptingAmazonS3 s3Client,
       ServerSideEncryptingAmazonS3.Builder s3ClientBuilder,
       S3InputDataConfig inputDataConfig,
@@ -192,18 +191,19 @@ public class S3InputSource extends CloudObjectInputSource
       AWSClientConfig awsClientConfig
   )
   {
-    this(s3Client,
+    this(
-         s3ClientBuilder,
+        s3Client,
-         inputDataConfig,
+        s3ClientBuilder,
-         uris,
+        inputDataConfig,
-         prefixes,
+        null,
-         objects,
+        uris,
-         filter,
+        prefixes,
-         s3InputSourceConfig,
+        objects,
-         awsProxyConfig,
+        filter,
-         awsEndpointConfig,
+        s3InputSourceConfig,
-         awsClientConfig,
+        awsProxyConfig,
-         null
+        awsEndpointConfig,
+        awsClientConfig
     );
   }
 
@@ -227,6 +227,7 @@ public class S3InputSource extends CloudObjectInputSource
         s3Client,
         s3ClientBuilder,
         inputDataConfig,
+        null,
         uris,
         prefixes,
         objects,
@@ -234,8 +235,7 @@ public class S3InputSource extends CloudObjectInputSource
         s3InputSourceConfig,
         awsProxyConfig,
         awsEndpointConfig,
-        awsClientConfig,
+        awsClientConfig
-        null
     );
     this.maxRetries = maxRetries;
   }
@@ -278,6 +278,7 @@ public class S3InputSource extends CloudObjectInputSource
 
   @Nullable
   @JsonProperty("properties")
+  @JsonInclude(JsonInclude.Include.NON_NULL)
   public S3InputSourceConfig getS3InputSourceConfig()
   {
     return s3InputSourceConfig;
@@ -285,6 +286,7 @@ public class S3InputSource extends CloudObjectInputSource
 
   @Nullable
   @JsonProperty("proxyConfig")
+  @JsonInclude(JsonInclude.Include.NON_NULL)
   public AWSProxyConfig getAwsProxyConfig()
   {
     return awsProxyConfig;
@@ -292,6 +294,7 @@ public class S3InputSource extends CloudObjectInputSource
 
   @Nullable
   @JsonProperty("clientConfig")
+  @JsonInclude(JsonInclude.Include.NON_NULL)
   public AWSClientConfig getAwsClientConfig()
   {
     return awsClientConfig;
@@ -299,6 +302,7 @@ public class S3InputSource extends CloudObjectInputSource
 
   @Nullable
   @JsonProperty("endpointConfig")
+  @JsonInclude(JsonInclude.Include.NON_NULL)
   public AWSEndpointConfig getAwsEndpointConfig()
   {
     return awsEndpointConfig;
@@ -334,13 +338,13 @@ public class S3InputSource extends CloudObjectInputSource
         inputDataConfig,
         null,
         null,
+        null,
         split.get(),
         getFilter(),
         getS3InputSourceConfig(),
         getAwsProxyConfig(),
         getAwsEndpointConfig(),
-        getAwsClientConfig(),
+        getAwsClientConfig()
-        awsCredentialsProvider
     );
   }
 

extensions-core/s3-extensions/src/main/java/org/apache/druid/data/input/s3/S3InputSourceConfig.java

@@ -21,6 +21,7 @@ package org.apache.druid.data.input.s3;
 
 import com.fasterxml.jackson.annotation.JsonCreator;
 import com.fasterxml.jackson.annotation.JsonIgnore;
+import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.google.common.base.Preconditions;
 import org.apache.druid.metadata.PasswordProvider;
@@ -34,14 +35,10 @@ import java.util.Objects;
  */
 public class S3InputSourceConfig
 {
-  @JsonProperty
+  private final String assumeRoleArn;
-  private String assumeRoleArn;
+  private final String assumeRoleExternalId;
-  @JsonProperty
+  private final PasswordProvider accessKeyId;
-  private String assumeRoleExternalId;
+  private final PasswordProvider secretAccessKey;
-  @JsonProperty
-  private PasswordProvider accessKeyId;
-  @JsonProperty
-  private PasswordProvider secretAccessKey;
 
   @JsonCreator
   public S3InputSourceConfig(
@@ -56,28 +53,39 @@ public class S3InputSourceConfig
     if (accessKeyId != null || secretAccessKey != null) {
       this.accessKeyId = Preconditions.checkNotNull(accessKeyId, "accessKeyId cannot be null if secretAccessKey is given");
       this.secretAccessKey = Preconditions.checkNotNull(secretAccessKey, "secretAccessKey cannot be null if accessKeyId is given");
+    } else {
+      this.accessKeyId = null;
+      this.secretAccessKey = null;
     }
   }
 
   @Nullable
+  @JsonProperty
+  @JsonInclude(JsonInclude.Include.NON_NULL)
   public String getAssumeRoleArn()
   {
     return assumeRoleArn;
   }
 
   @Nullable
+  @JsonProperty
+  @JsonInclude(JsonInclude.Include.NON_NULL)
   public String getAssumeRoleExternalId()
   {
     return assumeRoleExternalId;
   }
 
   @Nullable
+  @JsonProperty
+  @JsonInclude(JsonInclude.Include.NON_NULL)
   public PasswordProvider getAccessKeyId()
   {
     return accessKeyId;
   }
 
   @Nullable
+  @JsonProperty
+  @JsonInclude(JsonInclude.Include.NON_NULL)
   public PasswordProvider getSecretAccessKey()
   {
     return secretAccessKey;

extensions-core/s3-extensions/src/test/java/org/apache/druid/data/input/s3/S3InputSourceConfigTest.java

@@ -0,0 +1,70 @@
+/*
+ * 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.druid.data.input.s3;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import nl.jqno.equalsverifier.EqualsVerifier;
+import org.apache.druid.metadata.DefaultPasswordProvider;
+import org.apache.druid.segment.TestHelper;
+import org.junit.Assert;
+import org.junit.Test;
+
+public class S3InputSourceConfigTest
+{
+  @Test
+  public void testSerdeAccessSecretKey() throws Exception
+  {
+    final ObjectMapper mapper = TestHelper.makeJsonMapper();
+    final S3InputSourceConfig config = new S3InputSourceConfig(
+        new DefaultPasswordProvider("the-access-key"),
+        new DefaultPasswordProvider("the-secret-key"),
+        null,
+        null
+    );
+
+    Assert.assertEquals(
+        config,
+        mapper.readValue(mapper.writeValueAsString(config), S3InputSourceConfig.class)
+    );
+  }
+
+  @Test
+  public void testSerdeAssumeRole() throws Exception
+  {
+    final ObjectMapper mapper = TestHelper.makeJsonMapper();
+    final S3InputSourceConfig config = new S3InputSourceConfig(
+        null,
+        null,
+        "the-role-arn",
+        "the-role-external-id"
+    );
+
+    Assert.assertEquals(
+        config,
+        mapper.readValue(mapper.writeValueAsString(config), S3InputSourceConfig.class)
+    );
+  }
+
+  @Test
+  public void testEquals()
+  {
+    EqualsVerifier.forClass(S3InputSourceConfig.class).usingGetClass().verify();
+  }
+}