From fede584b9811f35432a936af0c9441f4e05df80a Mon Sep 17 00:00:00 2001
From: Inderjeet Singh <inder123@gmail.com>
Date: Fri, 9 Sep 2011 06:23:17 +0000
Subject: [PATCH] Gson 2.0 converts JSON with type Object.class into something
 meaningful such as a Collection of primitives or Maps. Updated tests for the
 new behavior. Changed $Gson$Types.getCollectionElementType to handle
 wild-card sub-classes of collections and raw collections.

---
 .../com/google/gson/internal/$Gson$Types.java | 10 +++-
 .../gson/functional/CollectionTest.java       | 51 +++++++++----------
 2 files changed, 34 insertions(+), 27 deletions(-)

diff --git a/gson/src/main/java/com/google/gson/internal/$Gson$Types.java b/gson/src/main/java/com/google/gson/internal/$Gson$Types.java
index f03dc77f..9fc70ed6 100644
--- a/gson/src/main/java/com/google/gson/internal/$Gson$Types.java
+++ b/gson/src/main/java/com/google/gson/internal/$Gson$Types.java
@@ -18,6 +18,7 @@ package com.google.gson.internal;
 
 import static com.google.gson.internal.$Gson$Preconditions.checkArgument;
 import static com.google.gson.internal.$Gson$Preconditions.checkNotNull;
+
 import java.io.Serializable;
 import java.lang.reflect.Array;
 import java.lang.reflect.GenericArrayType;
@@ -297,7 +298,14 @@ public final class $Gson$Types {
    */
   public static Type getCollectionElementType(Type context, Class<?> contextRawType) {
     Type collectionType = getSupertype(context, contextRawType, Collection.class);
-    return ((ParameterizedType) collectionType).getActualTypeArguments()[0];
+    
+    if (collectionType instanceof WildcardType) {
+      collectionType = ((WildcardType)collectionType).getUpperBounds()[0];
+    }
+    if (collectionType instanceof ParameterizedType) {
+      return ((ParameterizedType) collectionType).getActualTypeArguments()[0];
+    }
+    return Object.class;
   }
 
   /**
diff --git a/gson/src/test/java/com/google/gson/functional/CollectionTest.java b/gson/src/test/java/com/google/gson/functional/CollectionTest.java
index 2a068735..97fdf5ee 100644
--- a/gson/src/test/java/com/google/gson/functional/CollectionTest.java
+++ b/gson/src/test/java/com/google/gson/functional/CollectionTest.java
@@ -16,14 +16,6 @@
 
 package com.google.gson.functional;
 
-import com.google.gson.Gson;
-import com.google.gson.JsonParseException;
-import com.google.gson.common.MoreAsserts;
-import com.google.gson.common.TestTypes.BagOfPrimitives;
-import com.google.gson.reflect.TypeToken;
-
-import junit.framework.TestCase;
-
 import java.lang.reflect.Type;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -32,9 +24,18 @@ import java.util.HashSet;
 import java.util.Iterator;
 import java.util.LinkedList;
 import java.util.List;
+import java.util.Map;
 import java.util.Queue;
 import java.util.Set;
 
+import junit.framework.TestCase;
+
+import com.google.gson.Gson;
+import com.google.gson.JsonParseException;
+import com.google.gson.common.MoreAsserts;
+import com.google.gson.common.TestTypes.BagOfPrimitives;
+import com.google.gson.reflect.TypeToken;
+
 /**
  * Functional tests for Json serialization and deserialization of collections.
  *
@@ -210,30 +211,28 @@ public class CollectionTest extends TestCase {
 
   public void testRawCollectionDeserializationNotAlllowed() {
     String json = "[0,1,2,3,4,5,6,7,8,9]";
-    try {
-        gson.fromJson(json, Collection.class);
-        fail("Can not deserialize a non-genericized collection.");
-    } catch (JsonParseException expected) { }
+    Collection integers = gson.fromJson(json, Collection.class);
+    // JsonReader converts numbers to double by default so we need a floating point comparison
+    assertEquals(Arrays.asList(0.0, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0), integers);
 
     json = "[\"Hello\", \"World\"]";
-    try {
-      gson.fromJson(json, Collection.class);
-      fail("Can not deserialize a non-genericized collection.");
-    } catch (JsonParseException expected) { }
+    Collection strings = gson.fromJson(json, Collection.class);
+    assertTrue(strings.contains("Hello"));
+    assertTrue(strings.contains("World"));
   }
 
   @SuppressWarnings("unchecked")
   public void testRawCollectionOfBagOfPrimitivesNotAllowed() {
-    try {
-      BagOfPrimitives bag = new BagOfPrimitives(10, 20, false, "stringValue");
-      String json = '[' + bag.getExpectedJson() + ',' + bag.getExpectedJson() + ']';
-      Collection target = gson.fromJson(json, Collection.class);
-      assertEquals(2, target.size());
-      for (BagOfPrimitives bag1 : (Collection<BagOfPrimitives>) target) {
-        assertEquals(bag.getExpectedJson(), bag1.getExpectedJson());
-      }
-      fail("Raw collection of objects should not work");
-    } catch (JsonParseException expected) {
+    BagOfPrimitives bag = new BagOfPrimitives(10, 20, false, "stringValue");
+    String json = '[' + bag.getExpectedJson() + ',' + bag.getExpectedJson() + ']';
+    Collection target = gson.fromJson(json, Collection.class);
+    assertEquals(2, target.size());
+    for (Object bag1 : target) {
+      // Gson 2.0 converts raw objects into maps
+      Map<String, Object> values = (Map<String, Object>) bag1;
+      assertTrue(values.containsValue(10.0));
+      assertTrue(values.containsValue(20.0));
+      assertTrue(values.containsValue("stringValue"));
     }
   }