Allow user to pass function to convert Object to JSON

Author: andrebonna

src/main/java/io/github/jsonSnapshot/Snapshot.java

@@ -1,14 +1,13 @@
 package io.github.jsonSnapshot;
 
-import com.google.gson.Gson;
-import com.google.gson.GsonBuilder;
 import org.assertj.core.util.diff.DiffUtils;
 import org.assertj.core.util.diff.Patch;
 
 import java.lang.reflect.Method;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Set;
+import java.util.function.Function;
 
 public class Snapshot {
 
@@ -18,16 +17,16 @@ public class Snapshot {
 
     private Method method;
 
-    private Gson gson;
+    private Function<Object, String> jsonFunction;
 
     private Object[] current;
 
-    Snapshot(SnapshotFile snapshotFile, Class clazz, Method method, Object... current) {
+    Snapshot(SnapshotFile snapshotFile, Class clazz, Method method, Function<Object, String> jsonFunction, Object... current) {
         this.current = current;
         this.snapshotFile = snapshotFile;
         this.clazz = clazz;
         this.method = method;
-        gson = new GsonBuilder().setPrettyPrinting().create();
+        this.jsonFunction = jsonFunction;
     }
 
     public void toMatchSnapshot() {
@@ -71,7 +70,7 @@ private String getRawSnapshot(Collection<String> rawSnapshots) {
     }
 
     private String takeSnapshot() {
-        return getSnapshotName() + gson.toJson(current);
+        return getSnapshotName() + jsonFunction.apply(current);
     }
 
     public String getSnapshotName() {

src/main/java/io/github/jsonSnapshot/SnapshotMatcher.java

@@ -1,5 +1,6 @@
 package io.github.jsonSnapshot;
 
+import com.google.gson.GsonBuilder;
 import org.apache.commons.lang3.ArrayUtils;
 import org.apache.commons.lang3.StringUtils;
 import org.assertj.core.util.Arrays;
@@ -13,6 +14,8 @@
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Set;
+import java.util.function.Function;
+import java.util.function.Supplier;
 import java.util.stream.Collectors;
 
 public class SnapshotMatcher {
@@ -22,12 +25,22 @@ public class SnapshotMatcher {
     private static Class clazz = null;
     private static SnapshotFile snapshotFile = null;
     private static List<Snapshot> calledSnapshots = new ArrayList<>();
+    private static Function<Object, String> jsonFunction;
 
     public static void start() {
-        start(new DefaultConfig());
+        start(new DefaultConfig(), defaultJsonFunction());
     }
 
     public static void start(SnapshotConfig config) {
+        start(config, defaultJsonFunction());
+    }
+
+    public static void start(Function<Object, String> jsonFunction) {
+        start(new DefaultConfig(), jsonFunction);
+    }
+
+    public static void start(SnapshotConfig config, Function<Object, String> jsonFunction) {
+        SnapshotMatcher.jsonFunction = jsonFunction;
         try {
             StackTraceElement stackElement = findStackElement();
             clazz = Class.forName(stackElement.getClassName());
@@ -67,7 +80,7 @@ public static Snapshot expect(Object firstObject, Object... others) {
             Object[] objects = mergeObjects(firstObject, others);
             StackTraceElement stackElement = findStackElement();
             Method method = getMethod(stackElement, clazz);
-            Snapshot snapshot = new Snapshot(snapshotFile, clazz, method, objects);
+            Snapshot snapshot = new Snapshot(snapshotFile, clazz, method, jsonFunction, objects);
             validateExpectCall(snapshot);
             calledSnapshots.add(snapshot);
             return snapshot;
@@ -76,6 +89,10 @@ public static Snapshot expect(Object firstObject, Object... others) {
         }
     }
 
+    private static Function<Object, String> defaultJsonFunction() {
+        return (object) -> new GsonBuilder().setPrettyPrinting().create().toJson(object);
+    }
+
     private static void validateExpectCall(Snapshot snapshot) {
         for (Snapshot eachSnapshot : calledSnapshots) {
             if (eachSnapshot.getSnapshotName().equals(snapshot.getSnapshotName())) {

src/test/java/io/github/jsonSnapshot/SnapshotTest.java

@@ -1,5 +1,6 @@
 package io.github.jsonSnapshot;
 
+import com.google.gson.GsonBuilder;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
@@ -32,7 +33,8 @@ public class SnapshotTest {
     public void setUp() throws NoSuchMethodException, IOException {
         snapshotFile = new SnapshotFile(DEFAULT_CONFIG.getFilePath(), "anyFilePath");
         snapshot = new Snapshot(snapshotFile, String.class,
-                String.class.getDeclaredMethod("toString"), "anyObject");
+                String.class.getDeclaredMethod("toString"),
+                (object) -> new GsonBuilder().setPrettyPrinting().create().toJson(object),"anyObject");
     }
 
     @After