From a684a2a66ba31daa6888de6170cccadfe11dfe43 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Gerg=C5=91=20Tisza?= <gtisza@wikimedia.org>
Date: Sun, 7 Feb 2016 08:12:10 +0000
Subject: [PATCH] Add MediaWikiTestCase convenience method for mocking a logger

Change-Id: I2f96eddf9f010333ab515c980f4158dce410a13a
---
 tests/phpunit/MediaWikiTestCase.php           | 66 +++++++++++++++++++
 tests/phpunit/tests/MediaWikiTestCaseTest.php | 34 ++++++++++
 2 files changed, 100 insertions(+)

diff --git a/tests/phpunit/MediaWikiTestCase.php b/tests/phpunit/MediaWikiTestCase.php
index f69e342ad4..2e1e2706b6 100644
--- a/tests/phpunit/MediaWikiTestCase.php
+++ b/tests/phpunit/MediaWikiTestCase.php
@@ -1,4 +1,8 @@
 <?php
+use MediaWiki\Logger\LegacySpi;
+use MediaWiki\Logger\LoggerFactory;
+use MediaWiki\Logger\MonologSpi;
+use Psr\Log\LoggerInterface;
 
 /**
  * @since 1.18
@@ -64,6 +68,12 @@ abstract class MediaWikiTestCase extends PHPUnit_Framework_TestCase {
 	 */
 	private $mwGlobals = array();
 
+	/**
+	 * Holds original loggers which have been replaced by setLogger()
+	 * @var LoggerInterface[]
+	 */
+	private $loggers = array();
+
 	/**
 	 * Table name prefixes. Oracle likes it shorter.
 	 */
@@ -252,6 +262,7 @@ abstract class MediaWikiTestCase extends PHPUnit_Framework_TestCase {
 			$GLOBALS[$key] = $value;
 		}
 		$this->mwGlobals = array();
+		$this->restoreLoggers();
 		RequestContext::resetMain();
 		MediaHandler::resetCache();
 		if ( session_id() !== '' ) {
@@ -404,6 +415,61 @@ abstract class MediaWikiTestCase extends PHPUnit_Framework_TestCase {
 		$this->setMwGlobals( $name, $merged );
 	}
 
+	/**
+	 * Sets the logger for a specified channel, for the duration of the test.
+	 * @since 1.27
+	 * @param string $channel
+	 * @param LoggerInterface $logger
+	 */
+	protected function setLogger( $channel, LoggerInterface $logger ) {
+		$provider = LoggerFactory::getProvider();
+		$wrappedProvider = TestingAccessWrapper::newFromObject( $provider );
+		$singletons = $wrappedProvider->singletons;
+		if ( $provider instanceof MonologSpi ) {
+			if ( !isset( $this->loggers[$channel] ) ) {
+				$this->loggers[$channel] = isset( $singletons['loggers'][$channel] )
+					? $singletons['loggers'][$channel] : null;
+			}
+			$singletons['loggers'][$channel] = $logger;
+		} elseif ( $provider instanceof LegacySpi ) {
+			if ( !isset( $this->loggers[$channel] ) ) {
+				$this->loggers[$channel] = isset( $singletons[$channel] ) ? $singletons[$channel] : null;
+			}
+			$singletons[$channel] = $logger;
+		} else {
+			throw new LogicException( __METHOD__ . ': setting a logger for ' . get_class( $provider )
+				. ' is not implemented' );
+		}
+		$wrappedProvider->singletons = $singletons;
+	}
+
+	/**
+	 * Restores loggers replaced by setLogger().
+	 * @since 1.27
+	 */
+	private function restoreLoggers() {
+		$provider = LoggerFactory::getProvider();
+		$wrappedProvider = TestingAccessWrapper::newFromObject( $provider );
+		$singletons = $wrappedProvider->singletons;
+		foreach ( $this->loggers as $channel => $logger ) {
+			if ( $provider instanceof MonologSpi ) {
+				if ( $logger === null ) {
+					unset( $singletons['loggers'][$channel] );
+				} else {
+					$singletons['loggers'][$channel] = $logger;
+				}
+			} elseif ( $provider instanceof LegacySpi ) {
+				if ( $logger === null ) {
+					unset( $singletons[$channel] );
+				} else {
+					$singletons[$channel] = $logger;
+				}
+			}
+		}
+		$wrappedProvider->singletons = $singletons;
+		$this->loggers = array();
+	}
+
 	/**
 	 * @return string
 	 * @since 1.18
diff --git a/tests/phpunit/tests/MediaWikiTestCaseTest.php b/tests/phpunit/tests/MediaWikiTestCaseTest.php
index 8887499797..33611665dc 100644
--- a/tests/phpunit/tests/MediaWikiTestCaseTest.php
+++ b/tests/phpunit/tests/MediaWikiTestCaseTest.php
@@ -1,4 +1,5 @@
 <?php
+use MediaWiki\Logger\LoggerFactory;
 
 /**
  * @covers MediaWikiTestCase
@@ -97,4 +98,37 @@ class MediaWikiTestCaseTest extends MediaWikiTestCase {
 		$this->stashMwGlobals( self::GLOBAL_KEY_NONEXISTING );
 	}
 
+	/**
+	 * @covers MediaWikiTestCase::setLogger
+	 * @covers MediaWikiTestCase::restoreLogger
+	 */
+	public function testLoggersAreRestoredOnTearDown() {
+		// replacing an existing logger
+		$logger1 = LoggerFactory::getInstance( 'foo' );
+		$this->setLogger( 'foo', $this->getMock( '\Psr\Log\LoggerInterface' ) );
+		$logger2 = LoggerFactory::getInstance( 'foo' );
+		$this->tearDown();
+		$logger3 = LoggerFactory::getInstance( 'foo' );
+
+		$this->assertSame( $logger1, $logger3 );
+		$this->assertNotSame( $logger1, $logger2 );
+
+		// replacing a non-existing logger
+		$this->setLogger( 'bar', $this->getMock( '\Psr\Log\LoggerInterface' ) );
+		$logger1 = LoggerFactory::getInstance( 'bar' );
+		$this->tearDown();
+		$logger2 = LoggerFactory::getInstance( 'bar' );
+
+		$this->assertNotSame( $logger1, $logger2 );
+		$this->assertInstanceOf( '\Psr\Log\LoggerInterface', $logger2 );
+
+		// replacing same logger twice
+		$logger1 = LoggerFactory::getInstance( 'baz' );
+		$this->setLogger( 'baz', $this->getMock( '\Psr\Log\LoggerInterface' ) );
+		$this->setLogger( 'baz', $this->getMock( '\Psr\Log\LoggerInterface' ) );
+		$this->tearDown();
+		$logger2 = LoggerFactory::getInstance( 'baz' );
+
+		$this->assertSame( $logger1, $logger2 );
+	}
 }
-- 
2.20.1