From 78befbb5ee80fb8e403f76375c8d693c60ba46e0 Mon Sep 17 00:00:00 2001
From: Jochen Berger <fooberger@gmail.com>
Date: Thu, 29 Jun 2017 12:48:13 +0200
Subject: [PATCH] `null` should be mapped to `null` (fixes #351)

---
 .../spi/mapper/GsonMappingProvider.java       |  6 ++++++
 .../jayway/jsonpath/GsonJsonProviderTest.java | 21 +++++++++++++++++++
 2 files changed, 27 insertions(+)

diff --git a/json-path/src/main/java/com/jayway/jsonpath/spi/mapper/GsonMappingProvider.java b/json-path/src/main/java/com/jayway/jsonpath/spi/mapper/GsonMappingProvider.java
index 7e5153b4..2b5ead3c 100644
--- a/json-path/src/main/java/com/jayway/jsonpath/spi/mapper/GsonMappingProvider.java
+++ b/json-path/src/main/java/com/jayway/jsonpath/spi/mapper/GsonMappingProvider.java
@@ -62,6 +62,9 @@ public class GsonMappingProvider implements MappingProvider {
 
     @Override
     public <T> T map(Object source, Class<T> targetType, Configuration configuration) {
+        if(source == null){
+            return null;
+        }
         try {
             return factory.call().getAdapter(targetType).fromJsonTree((JsonElement) source);
         } catch (Exception e){
@@ -71,6 +74,9 @@ public class GsonMappingProvider implements MappingProvider {
 
     @Override
     public <T> T map(Object source, TypeRef<T> targetType, Configuration configuration) {
+        if(source == null){
+            return null;
+        }
         try {
             return (T) factory.call().getAdapter(TypeToken.get(targetType.getType())).fromJsonTree((JsonElement) source);
         } catch (Exception e){
diff --git a/json-path/src/test/java/com/jayway/jsonpath/GsonJsonProviderTest.java b/json-path/src/test/java/com/jayway/jsonpath/GsonJsonProviderTest.java
index 1fc85bd9..5cca22b4 100644
--- a/json-path/src/test/java/com/jayway/jsonpath/GsonJsonProviderTest.java
+++ b/json-path/src/test/java/com/jayway/jsonpath/GsonJsonProviderTest.java
@@ -3,6 +3,8 @@ package com.jayway.jsonpath;
 import com.google.gson.JsonArray;
 import com.google.gson.JsonElement;
 import com.google.gson.JsonObject;
+import com.jayway.jsonpath.spi.json.GsonJsonProvider;
+import com.jayway.jsonpath.spi.mapper.GsonMappingProvider;
 import com.jayway.jsonpath.spi.mapper.MappingException;
 import org.junit.Test;
 
@@ -181,6 +183,25 @@ public class GsonJsonProviderTest extends BaseTest {
 
         using(GSON_CONFIGURATION).parse(JSON).read("$", typeRef);
     }
+    
+    @Test
+    // https://github.com/json-path/JsonPath/issues/351
+    public void no_error_when_mapping_null() throws IOException {
+      
+      Configuration configuration = Configuration
+          .builder()
+          .mappingProvider(new GsonMappingProvider())
+          .jsonProvider(new GsonJsonProvider())
+          .options(Option.DEFAULT_PATH_LEAF_TO_NULL, Option.SUPPRESS_EXCEPTIONS)
+          .build();
+      
+      String json = "{\"M\":[]}";
+
+      String result = JsonPath.using(configuration).parse(json).read("$.M[0].A[0]", String.class);
+
+      assertThat(result).isNull();
+    }
+
 
     public static class FooBarBaz<T> {
         public T gen;