From e53600c4b6471cd1391816570c423c8fd0828502 Mon Sep 17 00:00:00 2001
From: Bryan Davis <bd808@wikimedia.org>
Date: Thu, 30 Jul 2015 11:24:07 -0600
Subject: [PATCH] ObjectFactory: add support for setter injection

Extend ObjectFactory::getObjectFromSpec() to support setter injection on
created objects when the specification includes a 'calls' member.

Bug: T107440
Change-Id: Ie2ece2e9658dd2d895d3935da4dc2da8a0a316e2
---
 includes/libs/ObjectFactory.php               | 49 ++++++++++++++-----
 .../includes/libs/ObjectFactoryTest.php       | 25 ++++++++++
 2 files changed, 63 insertions(+), 11 deletions(-)

diff --git a/includes/libs/ObjectFactory.php b/includes/libs/ObjectFactory.php
index ec8c36a1df..1cb544b8b8 100644
--- a/includes/libs/ObjectFactory.php
+++ b/includes/libs/ObjectFactory.php
@@ -49,6 +49,13 @@ class ObjectFactory {
 	 * constructor/callable. This behavior can be suppressed by adding
 	 * closure_expansion => false to the specification.
 	 *
+	 * The specification may also contain a 'calls' key that describes method
+	 * calls to make on the newly created object before returning it. This
+	 * pattern is often known as "setter injection". The value of this key is
+	 * expected to be an associative array with method names as keys and
+	 * argument lists as values. The argument list will be expanded (or not)
+	 * in the same way as the 'args' key for the main object.
+	 *
 	 * @param array $spec Object specification
 	 * @return object
 	 * @throws InvalidArgumentException when object specification does not
@@ -58,18 +65,11 @@ class ObjectFactory {
 	 */
 	public static function getObjectFromSpec( $spec ) {
 		$args = isset( $spec['args'] ) ? $spec['args'] : array();
+		$expandArgs = !isset( $spec['closure_expansion'] ) ||
+			$spec['closure_expansion'] === true;
 
-		if ( !isset( $spec['closure_expansion'] ) ||
-			$spec['closure_expansion'] === true
-		) {
-			$args = array_map( function ( $value ) {
-				if ( is_object( $value ) && $value instanceof Closure ) {
-					// If an argument is a Closure, call it.
-					return $value();
-				} else {
-					return $value;
-				}
-			}, $args );
+		if ( $expandArgs ) {
+			$args = static::expandClosures( $args );
 		}
 
 		if ( isset( $spec['class'] ) ) {
@@ -88,6 +88,33 @@ class ObjectFactory {
 			);
 		}
 
+		if ( isset( $spec['calls'] ) && is_array( $spec['calls'] ) ) {
+			// Call additional methods on the newly created object
+			foreach ( $spec['calls'] as $method => $margs ) {
+				if ( $expandArgs ) {
+					$margs = static::expandClosures( $margs );
+				}
+				call_user_func_array( array( $obj, $method ), $margs );
+			}
+		}
+
 		return $obj;
 	}
+
+	/**
+	 * Iterate a list and call any closures it contains.
+	 *
+	 * @param array $list List of things
+	 * @return array List with any Closures replaced with their output
+	 */
+	protected static function expandClosures( $list ) {
+		return array_map( function ( $value ) {
+			if ( is_object( $value ) && $value instanceof Closure ) {
+				// If $value is a Closure, call it.
+				return $value();
+			} else {
+				return $value;
+			}
+		}, $list );
+	}
 }
diff --git a/tests/phpunit/includes/libs/ObjectFactoryTest.php b/tests/phpunit/includes/libs/ObjectFactoryTest.php
index a9d3cc1b20..aea037e0fe 100644
--- a/tests/phpunit/includes/libs/ObjectFactoryTest.php
+++ b/tests/phpunit/includes/libs/ObjectFactoryTest.php
@@ -29,10 +29,17 @@ class ObjectFactoryTest extends PHPUnit_Framework_TestCase {
 			'args' => array( function() {
 				return 'unwrapped';
 			}, ),
+			'calls' => array(
+				'setter' => array( function() {
+					return 'unwrapped';
+				}, ),
+			),
 			'closure_expansion' => false,
 		) );
 		$this->assertInstanceOf( 'Closure', $obj->args[0] );
 		$this->assertSame( 'unwrapped', $obj->args[0]() );
+		$this->assertInstanceOf( 'Closure', $obj->setterArgs[0] );
+		$this->assertSame( 'unwrapped', $obj->setterArgs[0]() );
 	}
 
 	/**
@@ -44,25 +51,43 @@ class ObjectFactoryTest extends PHPUnit_Framework_TestCase {
 			'args' => array( function() {
 				return 'unwrapped';
 			}, ),
+			'calls' => array(
+				'setter' => array( function() {
+					return 'unwrapped';
+				}, ),
+			),
 			'closure_expansion' => true,
 		) );
 		$this->assertInternalType( 'string', $obj->args[0] );
 		$this->assertSame( 'unwrapped', $obj->args[0] );
+		$this->assertInternalType( 'string', $obj->setterArgs[0] );
+		$this->assertSame( 'unwrapped', $obj->setterArgs[0] );
 
 		$obj = ObjectFactory::getObjectFromSpec( array(
 			'class' => 'ObjectFactoryTest_Fixture',
 			'args' => array( function() {
 				return 'unwrapped';
 			}, ),
+			'calls' => array(
+				'setter' => array( function() {
+					return 'unwrapped';
+				}, ),
+			),
 		) );
 		$this->assertInternalType( 'string', $obj->args[0] );
 		$this->assertSame( 'unwrapped', $obj->args[0] );
+		$this->assertInternalType( 'string', $obj->setterArgs[0] );
+		$this->assertSame( 'unwrapped', $obj->setterArgs[0] );
 	}
 }
 
 class ObjectFactoryTest_Fixture {
 	public $args;
+	public $setterArgs;
 	public function __construct( /*...*/ ) {
 		$this->args = func_get_args();
 	}
+	public function setter( /*...*/ ) {
+		$this->setterArgs = func_get_args();
+	}
 }
-- 
2.20.1