fix: Make null key serialization/deserialization symmetrical (#4351)

confluentinc · Jan 20, 2020 · 2a61acb · 2a61acb
1 parent 4a74d24
commit 2a61acb
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Showing 3 changed files with 46 additions and 3 deletions.
diff --git a/ksql-functional-tests/src/test/resources/query-validation-tests/table.json b/ksql-functional-tests/src/test/resources/query-validation-tests/table.json
@@ -74,6 +74,22 @@
         {"topic": "OUTPUT", "key": "1", "value": null},
         {"topic": "OUTPUT", "key": "1", "value": "2"}
       ]
+    },
+    {
+      "name": "should not blow up on null key",
+      "statements": [
+        "CREATE TABLE INPUT (ID bigint) WITH (kafka_topic='test_topic', value_format='DELIMITED');",
+        "CREATE TABLE OUTPUT as SELECT * FROM INPUT;"
+      ],
+      "inputs": [
+        {"topic": "test_topic", "key": "1", "value": "1"},
+        {"topic": "test_topic", "key": null, "value": "2"},
+        {"topic": "test_topic", "key": "1", "value": "3"}
+      ],
+      "outputs": [
+        {"topic": "OUTPUT", "key": "1", "value": "1"},
+        {"topic": "OUTPUT", "key": "1", "value": "3"}
+      ]
     }
   ]
 }
diff --git a/ksql-serde/src/main/java/io/confluent/ksql/serde/kafka/KafkaSerdeFactory.java b/ksql-serde/src/main/java/io/confluent/ksql/serde/kafka/KafkaSerdeFactory.java
@@ -116,7 +116,7 @@ private static final class RowSerializer implements Serializer<Object> {
 
     @Override
     public byte[] serialize(final String topic, final Object struct) {
-      final Object value = ((Struct) struct).get(field);
+      final Object value = struct == null ? null : ((Struct) struct).get(field);
       return delegate.serialize(topic, value);
     }
   }
@@ -140,6 +140,9 @@ private static final class RowDeserializer implements Deserializer<Object> {
     public Struct deserialize(final String topic, final byte[] bytes) {
       try {
         final Object primitive = delegate.deserialize(topic, bytes);
+        if (primitive == null) {
+          return null;
+        }
         final Struct struct = new Struct(schema);
         struct.put(field, primitive);
         return struct;

diff --git a/ksql-serde/src/test/java/io/confluent/ksql/serde/kafka/KafkaSerdeFactoryTest.java b/ksql-serde/src/test/java/io/confluent/ksql/serde/kafka/KafkaSerdeFactoryTest.java
@@ -17,6 +17,7 @@
 
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.nullValue;
 
 import io.confluent.kafka.schemaregistry.client.SchemaRegistryClient;
 import io.confluent.ksql.name.ColumnName;
@@ -146,8 +147,31 @@ public void shouldThrowOnValidateIfStruct() {
   }
 
   @Test
-  public void shouldHandleNulls() {
-    shouldHandle(SqlTypes.INTEGER, null);
+  public void shouldSerializeNullAsNull() {
+    // Given:
+    final PersistenceSchema schema = schemaWithFieldOfType(SqlTypes.INTEGER);
+
+    final Serde<Object> serde = factory.createSerde(schema, ksqlConfig, srClientFactory);
+
+    // When:
+    final byte[] result = serde.serializer().serialize("topic", null);
+
+    // Then:
+    assertThat(result, is(nullValue()));
+  }
+
+  @Test
+  public void shouldDeserializeNullAsNull() {
+    // Given:
+    final PersistenceSchema schema = schemaWithFieldOfType(SqlTypes.INTEGER);
+
+    final Serde<Object> serde = factory.createSerde(schema, ksqlConfig, srClientFactory);
+
+    // When:
+    final Object result = serde.deserializer().deserialize("topic", null);
+
+    // Then:
+    assertThat(result, is(nullValue()));
   }
 
   @Test