Revert "Remove Entity::copy"

Author: JeroenDeDauw

RELEASE-NOTES.md

@@ -1,11 +1,5 @@
 # Wikibase DataModel release notes
 
-## Version 5.0 (dev)
-
-#### Breaking changes
-
-* Removed `Entity::copy`
-
 ## Version 4.0 (2015-07-28)
 
 #### Breaking changes

src/Entity/Entity.php

@@ -288,6 +288,18 @@ public function setAllAliases( array $aliasLists ) {
 		}
 	}
 
+	/**
+	 * Returns a deep copy of the entity.
+	 *
+	 * @since 0.1
+	 * @deprecated since 1.0
+	 *
+	 * @return self
+	 */
+	public function copy() {
+		return unserialize( serialize( $this ) );
+	}
+
 	/**
 	 * @since 0.3
 	 * @deprecated since 1.0, use getStatements()->toArray() instead.

tests/unit/Entity/EntityTest.php

@@ -360,6 +360,32 @@ public function instanceProvider() {
 		return $argLists;
 	}
 
+	/**
+	 * @dataProvider instanceProvider
+	 * @param Entity $entity
+	 */
+	public function testCopy( Entity $entity ) {
+		$copy = $entity->copy();
+
+		// The equality method alone is not enough since it does not check the IDs.
+		$this->assertTrue( $entity->equals( $copy ) );
+		$this->assertEquals( $entity->getId(), $copy->getId() );
+
+		$this->assertFalse( $entity === $copy );
+	}
+
+	public function testCopyRetainsLabels() {
+		$item = new Item();
+
+		$item->getFingerprint()->setLabel( 'en', 'foo' );
+		$item->getFingerprint()->setLabel( 'de', 'bar' );
+
+		$newItem = unserialize( serialize( $item ) );
+
+		$this->assertTrue( $newItem->getFingerprint()->getLabels()->hasTermForLanguage( 'en' ) );
+		$this->assertTrue( $newItem->getFingerprint()->getLabels()->hasTermForLanguage( 'de' ) );
+	}
+
 	/**
 	 * @dataProvider instanceProvider
 	 * @param Entity $entity

tests/unit/Entity/ItemTest.php

@@ -80,7 +80,7 @@ public function itemProvider() {
 		$items[] = $item;
 
 		/** @var Item $item */
-		$item = unserialize( serialize( $item ) );
+		$item = $item->copy();
 		$item->getStatements()->addNewStatement(
 			new PropertyNoValueSnak( new PropertyId( 'P42' ) )
 		);