Implement equals and Hashcode on GenericData (#589)

* 936: Added hashCode(), toString() and equals() methods relaing on classInfo and unknownFields.

* 936: Changes after review.

* 936: Modified unit test.

* 936: Added more unit tests.

* 936: GenericJsonTest fixed because toString was updated in GenericData.

* 936: Changes after review.

* Update GenericData.java

google-http-client/src/main/java/com/google/api/client/util/GenericData.java

@@ -20,6 +20,7 @@
 import java.util.Iterator;
 import java.util.Locale;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Set;
 import java.util.concurrent.ConcurrentMap;
 
@@ -196,6 +197,28 @@ public final void setUnknownKeys(Map<String, Object> unknownFields) {
     this.unknownFields = unknownFields;
   }
 
+  @Override
+  public boolean equals(Object o) {
+    if (o == this) {
+      return true;
+    }
+    if (o == null || !(o instanceof GenericData)) {
+      return false;
+    }
+    GenericData that = (GenericData) o;
+    return super.equals(that) && Objects.equals(this.classInfo, that.classInfo);
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(super.hashCode(), classInfo);
+  }
+
+  @Override
+  public String toString() {
+    return "GenericData{" + "classInfo=" + classInfo.names + ", " + super.toString() + "}";
+  }
+
   /**
    * Returns the class information.
    *

google-http-client/src/test/java/com/google/api/client/json/GenericJsonTest.java

@@ -26,6 +26,6 @@ public class GenericJsonTest extends TestCase {
   public void testToString_noFactory() {
     GenericJson data = new GenericJson();
     data.put("a", "b");
-    assertEquals("{a=b}", data.toString());
+    assertEquals("GenericData{classInfo=[], {a=b}}", data.toString());
   }
 }

google-http-client/src/test/java/com/google/api/client/util/GenericDataTest.java

@@ -48,13 +48,66 @@ public void setFieldB(List<String> fieldB) {
     }
   }
 
+  private class GenericData1 extends GenericData {
+    public GenericData1() {
+      super(EnumSet.of(Flags.IGNORE_CASE));
+    }
+
+    @Key("FieldA")
+    public String fieldA;
+  }
+
+  private class GenericData2 extends GenericData {
+    public GenericData2() {
+      super(EnumSet.of(Flags.IGNORE_CASE));
+    }
+
+    @Key("FieldA")
+    public String fieldA;
+  }
+
+  public void testEquals_Symmetric() {
+    GenericData actual = new GenericData1();
+    actual.set("fieldA", "bar");
+    GenericData expected = new GenericData2();
+    // Test that objects are equal.
+    expected.set("fieldA", "bar");
+    assertNotSame(expected, actual);
+    assertTrue(expected.equals(expected) && actual.equals(actual));
+    // Test that objects not are equal.
+    expected.set("fieldA", "far");
+    assertFalse(expected.equals(actual) || actual.equals(expected));
+    assertFalse(expected.hashCode() == actual.hashCode());
+  }
+
+  public void testEquals_SymmetricWithSameClass() {
+    GenericData actual = new MyData();
+    actual.set("fieldA", "bar");
+    GenericData expected = new MyData();
+    // Test that objects are equal.
+    expected.set("fieldA", "bar");
+    assertNotSame(expected, actual);
+    assertTrue(expected.equals(expected) && actual.equals(actual));
+    assertTrue(expected.hashCode() == expected.hashCode());
+  }
+
+  public void testNotEquals_SymmetricWithSameClass() {
+    GenericData actual = new MyData();
+    actual.set("fieldA", "bar");
+    GenericData expected = new MyData();
+    // Test that objects are not equal.
+    expected.set("fieldA", "far");
+    assertNotSame(expected, actual);
+    assertFalse(expected.equals(actual) || actual.equals(expected));
+    assertFalse(expected.hashCode() == actual.hashCode());
+  }
 
   public void testClone_changingEntrySet() {
     GenericData data = new GenericData();
-    assertEquals("{}", data.toString());
+    assertEquals("GenericData{classInfo=[], {}}", data.toString());
     GenericData clone = data.clone();
     clone.set("foo", "bar");
-    assertEquals("{foo=bar}", clone.toString());
+    assertEquals("GenericData{classInfo=[], {foo=bar}}", clone.toString());
   }
 
   public void testSetIgnoreCase_unknownKey() {