Added unit test

src/java/voldemort/serialization/avro/versioned/AvroVersionedGenericSerializer.java

@@ -84,8 +84,6 @@ public byte[] toBytes(Object object) {
             SerializationUtils.close(output);
         }
 
-        byte version = newestVersion.byteValue();
-
         return output.toByteArray();
     }
 

test/unit/voldemort/serialization/avro/versioned/AvroBackwardsCompatibilityTest.java

@@ -0,0 +1,58 @@
+package voldemort.serialization.avro.versioned;
+
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.Map;
+
+import junit.framework.TestCase;
+
+import org.apache.avro.Schema;
+import org.apache.avro.generic.GenericData;
+import org.apache.avro.generic.GenericData.Record;
+import org.apache.avro.util.Utf8;
+
+/**
+ * A test that the json serialization remains compatible with older serialized
+ * data
+ * 
+ * 
+ */
+public class AvroBackwardsCompatibilityTest extends TestCase {
+
+    private static byte[] writeVersion0(Schema s0) {
+
+        GenericData.Record record = new GenericData.Record(s0);
+        record.put("original", new Utf8("Abhinay"));
+        AvroVersionedGenericSerializer serializer = new AvroVersionedGenericSerializer(s0.toString());
+        return serializer.toBytes(record);
+
+    }
+
+    private static Object readVersion0(Map<Integer, String> versions, byte[] versionZeroBytes) {
+
+        AvroVersionedGenericSerializer serializer = new AvroVersionedGenericSerializer(versions);
+        return serializer.toObject(versionZeroBytes);
+
+    }
+
+    public static void testAvroSchemaEvolution() throws IOException {
+
+        String versionZero = "{\"type\": \"record\", \"name\": \"myrec\",\"fields\": [{ \"name\": \"original\", \"type\": \"string\" }]}";
+
+        String versionOne = "{\"type\": \"record\", \"name\": \"myrec\",\"fields\": [{ \"name\": \"original\", \"type\": \"string\" } ,"
+                            + "{ \"name\": \"new-field\", \"type\": \"string\", \"default\":\"\" }]}";
+
+        Schema s0 = Schema.parse(versionZero);
+        Schema s1 = Schema.parse(versionOne);
+
+        Map<Integer, String> versions = new HashMap<Integer, String>();
+
+        versions.put(0, versionZero);
+        versions.put(1, versionOne);
+
+        byte[] versionZeroBytes = writeVersion0(s0);
+
+        GenericData.Record record = (Record) readVersion0(versions, versionZeroBytes);
+
+    }
+}