Add failing test case for issue #339 (#340)

Author: willsoto

avro/src/test/java/com/fasterxml/jackson/dataformat/avro/failing/FileSerializationTest.java

@@ -0,0 +1,66 @@
+package com.fasterxml.jackson.dataformat.avro.failing;
+
+import com.fasterxml.jackson.databind.SequenceWriter;
+import com.fasterxml.jackson.dataformat.avro.AvroFactory;
+import com.fasterxml.jackson.dataformat.avro.AvroGenerator;
+import com.fasterxml.jackson.dataformat.avro.AvroMapper;
+import com.fasterxml.jackson.dataformat.avro.AvroSchema;
+import com.fasterxml.jackson.dataformat.avro.AvroTestBase;
+import com.fasterxml.jackson.dataformat.avro.schema.AvroSchemaGenerator;
+import org.apache.avro.file.DataFileReader;
+import org.apache.avro.generic.GenericDatumReader;
+import org.apache.avro.generic.GenericRecord;
+import org.apache.avro.io.DatumReader;
+
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.FileOutputStream;
+import java.nio.file.Files;
+
+public class FileSerializationTest extends AvroTestBase {
+    public void testFileSerialization() throws Exception {
+        final Employee employee = new Employee();
+        employee.name = "Bobbee";
+        employee.age = 39;
+        employee.emails = new String[]{"[email protected]", "[email protected]"};
+        employee.boss = null;
+
+        final AvroFactory avroFactory = AvroFactory.builderWithApacheDecoder().enable(AvroGenerator.Feature.AVRO_FILE_OUTPUT).build();
+        final AvroSchemaGenerator generator = new AvroSchemaGenerator();
+
+        final AvroMapper mapper = AvroMapper.builder(avroFactory).build();
+        mapper.acceptJsonFormatVisitor(Employee.class, generator);
+
+        final AvroSchema generatedSchema = generator.getGeneratedSchema();
+
+        final File file = Files.createTempFile("employees", ".avro").toFile();
+        file.deleteOnExit();
+
+        final ByteArrayOutputStream out = new ByteArrayOutputStream();
+        final SequenceWriter writer = mapper.writer(generatedSchema).writeValues(out);
+
+        // Write multiple entries, this seems to be what makes it invalid.
+        writer.write(employee);
+        writer.write(employee);
+        writer.close();
+
+        // Write the bytes to a file
+        try (FileOutputStream outputStream = new FileOutputStream(file)) {
+            out.writeTo(outputStream);
+        }
+
+        final DatumReader<GenericRecord> datumReader = new GenericDatumReader<>(generatedSchema.getAvroSchema());
+
+        @SuppressWarnings("resource") final DataFileReader<GenericRecord> dataFileReader = new DataFileReader<>(file, datumReader);
+
+        GenericRecord output = dataFileReader.next();
+        assertNotNull(output);
+        assertEquals(output.get("name").toString(), employee.name);
+
+        // This line currently throws the following exception:
+        // org.apache.avro.AvroRuntimeException: java.io.IOException: Invalid sync!
+        output = dataFileReader.next();
+        assertNotNull(output);
+        assertEquals(output.get("name").toString(), employee.name);
+    }
+}