Make PlatformFee implements Serializable interface (#114)

build.gradle

@@ -6,7 +6,7 @@ apply plugin: 'com.github.johnrengelman.shadow'
 apply plugin: 'com.github.ben-manes.versions'
 
 group 'co.omise'
-version '4.0.0'
+version '4.0.1'
 
 sourceCompatibility = 1.8
 targetCompatibility = 1.8

src/main/java/co/omise/models/PlatformFee.java

@@ -2,7 +2,9 @@
 
 import com.fasterxml.jackson.annotation.JsonProperty;
 
-public class PlatformFee {
+import java.io.Serializable;
+
+public class PlatformFee implements Serializable {
     private long amount;
     private long fixed;
     private Double percentage;

src/test/java/co/omise/models/SerializationTest.java

@@ -9,7 +9,11 @@
 import org.junit.Test;
 
 import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
 import java.io.IOException;
+import java.io.NotSerializableException;
+import java.io.ObjectOutputStream;
+import java.io.OutputStream;
 import java.util.Map;
 
 public class SerializationTest extends OmiseTest {
@@ -20,6 +24,8 @@ public void testModelSerializability() throws IOException {
             byte[] sampleBytes = getResourceBytes(objectJsonName(testcase.getValue()));
             OmiseObject instance = serializer.deserialize(new ByteArrayInputStream(sampleBytes), testcase.getValue());
 
+            assertSerializable(instance);
+
             Map<String, Object> map = serializer.serializeToMap(instance);
             Map<String, Object> comparison = serializer.objectMapper().readValue(sampleBytes, new TypeReference<Map<String, Object>>() {
             });
@@ -29,6 +35,7 @@ public void testModelSerializability() throws IOException {
     }
 
     private void assertMapEquals(String prefix, Map<String, Object> expectedMap, Map<String, Object> actualMap) {
+
         MapDifference<String, Object> differences = Maps.difference(expectedMap, actualMap);
         if (differences.entriesDiffering().size() == 0 && differences.entriesOnlyOnLeft().size() == 0) {
             return; // all good : )
@@ -87,4 +94,17 @@ private String objectJsonName(Class klass) {
             return "/testdata/objects/" + fileName + "_object.json";
         }
     }
+
+    /**
+     * Check if object is serializable
+     *
+     * @param instance
+     * @throws NotSerializableException
+     */
+    private void assertSerializable(OmiseObject instance) throws IOException, NotSerializableException {
+        OutputStream out = new ByteArrayOutputStream();
+        ObjectOutputStream stream = new ObjectOutputStream(out);
+
+        stream.writeObject(instance);
+    }
 }