Improve test coverage for OutputPage
authorAryeh Gregor <ayg@aryeh.name>
Mon, 23 Jul 2018 18:26:32 +0000 (21:26 +0300)
committerKunal Mehta <legoktm@member.fsf.org>
Mon, 30 Jul 2018 12:08:54 +0000 (05:08 -0700)
Raises coverage locally from 16.10% to 26.81%.

Change-Id: Ib564624c644ee6620ac06872f5684831acaaaadb
Depends-On: I79c4e37092958c63a693194b27a9eafae70cb2f8

includes/OutputPage.php
tests/phpunit/includes/OutputPageTest.php

index 2e091f1..a1c5919 100644 (file)
@@ -780,7 +780,7 @@ class OutputPage extends ContextSource {
                # this breaks strtotime().
                $clientHeader = preg_replace( '/;.*$/', '', $clientHeader );
 
-               Wikimedia\suppressWarnings(); // E_STRICT system time bitching
+               Wikimedia\suppressWarnings(); // E_STRICT system time warnings
                $clientHeaderTime = strtotime( $clientHeader );
                Wikimedia\restoreWarnings();
                if ( !$clientHeaderTime ) {
index 73447c9..d3c7af5 100644 (file)
@@ -3,29 +3,71 @@
 use Wikimedia\TestingAccessWrapper;
 
 /**
- *
  * @author Matthew Flaschen
  *
  * @group Database
  * @group Output
- *
- * @todo factor tests in this class into providers and test methods
  */
 class OutputPageTest extends MediaWikiTestCase {
        const SCREEN_MEDIA_QUERY = 'screen and (min-width: 982px)';
        const SCREEN_ONLY_MEDIA_QUERY = 'only screen and (min-width: 982px)';
 
+       /**
+        * @dataProvider provideRedirect
+        *
+        * @covers OutputPage::__construct
+        * @covers OutputPage::redirect
+        * @covers OutputPage::getRedirect
+        */
+       public function testRedirect( $url, $code = null ) {
+               $op = $this->newInstance();
+               if ( isset( $code ) ) {
+                       $op->redirect( $url, $code );
+               } else {
+                       $op->redirect( $url );
+               }
+               $expectedUrl = str_replace( "\n", '', $url );
+               $this->assertSame( $expectedUrl, $op->getRedirect() );
+               $this->assertSame( $expectedUrl, $op->mRedirect );
+               $this->assertSame( $code ?? '302', $op->mRedirectCode );
+       }
+
+       public function provideRedirect() {
+               return [
+                       [ 'http://example.com' ],
+                       [ 'http://example.com', '400' ],
+                       [ 'http://example.com', 'squirrels!!!' ],
+                       [ "a\nb" ],
+               ];
+       }
+
+       /**
+        * @covers OutputPage::setCopyrightUrl
+        * @covers OutputPage::getHeadLinksArray
+        */
+       public function testSetCopyrightUrl() {
+               $op = $this->newInstance();
+               $op->setCopyrightUrl( 'http://example.com' );
+
+               $this->assertSame(
+                       Html::element( 'link', [ 'rel' => 'license', 'href' => 'http://example.com' ] ),
+                       $op->getHeadLinksArray()['copyright']
+               );
+       }
+
+       // @todo How to test setStatusCode?
+
        /**
         * @covers OutputPage::addMeta
         * @covers OutputPage::getMetaTags
         * @covers OutputPage::getHeadLinksArray
         */
        public function testMetaTags() {
-               $outputPage = $this->newInstance();
-               $outputPage->addMeta( 'http:expires', '0' );
-               $outputPage->addMeta( 'keywords', 'first' );
-               $outputPage->addMeta( 'keywords', 'second' );
-               $outputPage->addMeta( 'og:title', 'Ta-duh' );
+               $op = $this->newInstance();
+               $op->addMeta( 'http:expires', '0' );
+               $op->addMeta( 'keywords', 'first' );
+               $op->addMeta( 'keywords', 'second' );
+               $op->addMeta( 'og:title', 'Ta-duh' );
 
                $expected = [
                        [ 'http:expires', '0' ],
@@ -33,9 +75,9 @@ class OutputPageTest extends MediaWikiTestCase {
                        [ 'keywords', 'second' ],
                        [ 'og:title', 'Ta-duh' ],
                ];
-               $this->assertSame( $expected, $outputPage->getMetaTags() );
+               $this->assertSame( $expected, $op->getMetaTags() );
 
-               $links = $outputPage->getHeadLinksArray();
+               $links = $op->getHeadLinksArray();
                $this->assertContains( '<meta http-equiv="expires" content="0"/>', $links );
                $this->assertContains( '<meta name="keywords" content="first"/>', $links );
                $this->assertContains( '<meta name="keywords" content="second"/>', $links );
@@ -44,84 +86,317 @@ class OutputPageTest extends MediaWikiTestCase {
        }
 
        /**
-        * @covers OutputPage::setIndexPolicy
-        * @covers OutputPage::setFollowPolicy
+        * @covers OutputPage::addLink
+        * @covers OutputPage::getLinkTags
         * @covers OutputPage::getHeadLinksArray
         */
-       public function testRobotsPolicies() {
-               $outputPage = $this->newInstance();
-               $outputPage->setIndexPolicy( 'noindex' );
-               $outputPage->setFollowPolicy( 'nofollow' );
+       public function testAddLink() {
+               $op = $this->newInstance();
 
-               $links = $outputPage->getHeadLinksArray();
-               $this->assertContains( '<meta name="robots" content="noindex,nofollow"/>', $links );
+               $links = [
+                       [],
+                       [ 'rel' => 'foo', 'href' => 'http://example.com' ],
+               ];
+
+               foreach ( $links as $link ) {
+                       $op->addLink( $link );
+               }
+
+               $this->assertSame( $links, $op->getLinkTags() );
+
+               $result = $op->getHeadLinksArray();
+
+               foreach ( $links as $link ) {
+                       $this->assertContains( Html::element( 'link', $link ), $result );
+               }
        }
 
        /**
-        * Tests a particular case of transformCssMedia, using the given input, globals,
-        * expected return, and message
+        * @covers OutputPage::setCanonicalUrl
+        * @covers OutputPage::getCanonicalUrl
+        * @covers OutputPage::getHeadLinksArray
+        */
+       public function testSetCanonicalUrl() {
+               $op = $this->newInstance();
+               $op->setCanonicalUrl( 'http://example.comm' );
+               $op->setCanonicalUrl( 'http://example.com' );
+
+               $this->assertSame( 'http://example.com', $op->getCanonicalUrl() );
+
+               $headLinks = $op->getHeadLinksArray();
+
+               $this->assertContains( Html::element( 'link', [
+                       'rel' => 'canonical', 'href' => 'http://example.com'
+               ] ), $headLinks );
+
+               $this->assertNotContains( Html::element( 'link', [
+                       'rel' => 'canonical', 'href' => 'http://example.comm'
+               ] ), $headLinks );
+       }
+
+       /**
+        * @covers OutputPage::addScript
+        */
+       public function testAddScript() {
+               $op = $this->newInstance();
+               $op->addScript( 'some random string' );
+
+               $this->assertContains( "\nsome random string\n", "\n" . $op->getBottomScripts() . "\n" );
+       }
+
+       /**
+        * @covers OutputPage::addScriptFile
+        */
+       public function testAddScriptFile() {
+               $op = $this->newInstance();
+               $op->addScriptFile( '/somescript.js' );
+               $op->addScriptFile( '//example.com/somescript.js' );
+
+               $this->assertContains(
+                       "\n" . Html::linkedScript( '/somescript.js', $op->getCSPNonce() ) .
+                               Html::linkedScript( '//example.com/somescript.js', $op->getCSPNonce() ) . "\n",
+                       "\n" . $op->getBottomScripts() . "\n"
+               );
+       }
+
+       /**
+        * Test that addScriptFile() throws due to deprecation.
         *
-        * Asserts that $expectedReturn is returned.
+        * @covers OutputPage::addScriptFile
+        */
+       public function testAddDeprecatedScriptFileWarning() {
+               $this->setExpectedException( PHPUnit_Framework_Error_Deprecated::class,
+                       'Use of OutputPage::addScriptFile was deprecated in MediaWiki 1.24.' );
+
+               $op = $this->newInstance();
+               $op->addScriptFile( 'ignored-script.js' );
+       }
+
+       /**
+        * Test the actual behavior of the method (in the case where it doesn't throw, e.g., in
+        * production).  Since it threw an exception once in this file, it won't when we call it again.
         *
-        * options['printableQuery'] - value of query string for printable, or omitted for none
-        * options['handheldQuery'] - value of query string for handheld, or omitted for none
-        * options['media'] - passed into the method under the same name
-        * options['expectedReturn'] - expected return value
-        * options['message'] - PHPUnit message for assertion
+        * @covers OutputPage::addScriptFile
+        */
+       public function testAddDeprecatedScriptFileNoOp() {
+               $op = $this->newInstance();
+               $op->addScriptFile( 'ignored-script.js' );
+
+               $this->assertNotContains( 'ignored-script.js', '' . $op->getBottomScripts() );
+       }
+
+       /**
+        * @covers OutputPage::addInlineScript
+        */
+       public function testAddInlineScript() {
+               $op = $this->newInstance();
+               $op->addInlineScript( 'let foo = "bar";' );
+               $op->addInlineScript( 'alert( foo );' );
+
+               $this->assertContains(
+                       "\n" . Html::inlineScript( "\nlet foo = \"bar\";\n", $op->getCSPNonce() ) . "\n" .
+                               Html::inlineScript( "\nalert( foo );\n", $op->getCSPNonce() ) . "\n",
+                       "\n" . $op->getBottomScripts() . "\n"
+               );
+       }
+
+       // @todo How to test filterModules(), warnModuleTargetFilter(), getModules(), etc.?
+
+       /**
+        * @covers OutputPage::getTarget
+        * @covers OutputPage::setTarget
+        */
+       public function testSetTarget() {
+               $op = $this->newInstance();
+               $op->setTarget( 'foo' );
+
+               $this->assertSame( 'foo', $op->getTarget() );
+               // @todo What else?  Test some actual effect?
+       }
+
+       // @todo How to test addContentOverride(Callback)?
+
+       /**
+        * @covers OutputPage::getHeadItemsArray
+        * @covers OutputPage::addHeadItem
+        * @covers OutputPage::addHeadItems
+        * @covers OutputPage::hasHeadItem
+        */
+       public function testHeadItems() {
+               $op = $this->newInstance();
+               $op->addHeadItem( 'a', 'b' );
+               $op->addHeadItems( [ 'c' => '<d>&amp;', 'e' => 'f', 'a' => 'q' ] );
+               $op->addHeadItem( 'e', 'g' );
+               $op->addHeadItems( 'x' );
+
+               $this->assertSame( [ 'a' => 'q', 'c' => '<d>&amp;', 'e' => 'g', 'x' ],
+                       $op->getHeadItemsArray() );
+
+               $this->assertTrue( $op->hasHeadItem( 'a' ) );
+               $this->assertTrue( $op->hasHeadItem( 'c' ) );
+               $this->assertTrue( $op->hasHeadItem( 'e' ) );
+               $this->assertTrue( $op->hasHeadItem( '0' ) );
+
+               $this->assertContains( "\nq\n<d>&amp;\ng\nx\n",
+                       '' . $op->headElement( $op->getContext()->getSkin() ) );
+       }
+
+       /**
+        * @covers OutputPage::addBodyClasses
+        */
+       public function testAddBodyClasses() {
+               $op = $this->newInstance();
+               $op->addBodyClasses( 'a' );
+               $op->addBodyClasses( 'mediawiki' );
+               $op->addBodyClasses( 'b c' );
+               $op->addBodyClasses( [ 'd', 'e' ] );
+               $op->addBodyClasses( 'a' );
+
+               $this->assertContains( '"a mediawiki b c d e ltr',
+                       '' . $op->headElement( $op->getContext()->getSkin() ) );
+       }
+
+       /**
+        * @covers OutputPage::setArticleBodyOnly
+        * @covers OutputPage::getArticleBodyOnly
+        */
+       public function testArticleBodyOnly() {
+               $op = $this->newInstance();
+               $this->assertFalse( $op->getArticleBodyOnly() );
+
+               $op->setArticleBodyOnly( true );
+               $this->assertTrue( $op->getArticleBodyOnly() );
+
+               $op->addHTML( '<b>a</b>' );
+
+               $this->assertSame( '<b>a</b>', $op->output( true ) );
+       }
+
+       /**
+        * @covers OutputPage::setProperty
+        * @covers OutputPage::getProperty
+        */
+       public function testProperties() {
+               $op = $this->newInstance();
+
+               $this->assertNull( $op->getProperty( 'foo' ) );
+
+               $op->setProperty( 'foo', 'bar' );
+               $op->setProperty( 'baz', 'quz' );
+
+               $this->assertSame( 'bar', $op->getProperty( 'foo' ) );
+               $this->assertSame( 'quz', $op->getProperty( 'baz' ) );
+       }
+
+       /**
+        * @dataProvider provideCheckLastModified
         *
-        * @param array $args Key-value array of arguments as shown above
+        * @covers OutputPage::checkLastModified
+        * @covers OutputPage::getCdnCacheEpoch
         */
-       protected function assertTransformCssMediaCase( $args ) {
-               $queryData = [];
-               if ( isset( $args['printableQuery'] ) ) {
-                       $queryData['printable'] = $args['printableQuery'];
+       public function testCheckLastModified(
+               $timestamp, $ifModifiedSince, $expected, $config = [], $callback = null
+       ) {
+               $request = new FauxRequest();
+               if ( $ifModifiedSince ) {
+                       if ( is_numeric( $ifModifiedSince ) ) {
+                               // Unix timestamp
+                               $ifModifiedSince = date( 'D, d M Y H:i:s', $ifModifiedSince ) . ' GMT';
+                       }
+                       $request->setHeader( 'If-Modified-Since', $ifModifiedSince );
                }
 
-               if ( isset( $args['handheldQuery'] ) ) {
-                       $queryData['handheld'] = $args['handheldQuery'];
+               if ( !isset( $config['CacheEpoch'] ) ) {
+                       // Make sure it's not too recent
+                       $config['CacheEpoch'] = '20000101000000';
                }
 
-               $fauxRequest = new FauxRequest( $queryData, false );
-               $this->setMwGlobals( [
-                       'wgRequest' => $fauxRequest,
-               ] );
+               $op = $this->newInstance( $config, $request );
 
-               $actualReturn = OutputPage::transformCssMedia( $args['media'] );
-               $this->assertSame( $args['expectedReturn'], $actualReturn, $args['message'] );
+               if ( $callback ) {
+                       $callback( $op, $this );
+               }
+
+               // Avoid a complaint about not being able to disable compression
+               Wikimedia\suppressWarnings();
+               try {
+                       $this->assertEquals( $expected, $op->checkLastModified( $timestamp ) );
+               } finally {
+                       Wikimedia\restoreWarnings();
+               }
+       }
+
+       public function provideCheckLastModified() {
+               $lastModified = time() - 3600;
+               return [
+                       'Timestamp 0' =>
+                               [ '0', $lastModified, false ],
+                       'Timestamp Unix epoch' =>
+                               [ '19700101000000', $lastModified, false ],
+                       'Timestamp same as If-Modified-Since' =>
+                               [ $lastModified, $lastModified, true ],
+                       'Timestamp one second after If-Modified-Since' =>
+                               [ $lastModified + 1, $lastModified, false ],
+                       'No If-Modified-Since' =>
+                               [ $lastModified + 1, null, false ],
+                       'Malformed If-Modified-Since' =>
+                               [ $lastModified + 1, 'GIBBERING WOMBATS !!!', false ],
+                       'Non-standard IE-style If-Modified-Since' =>
+                               [ $lastModified, date( 'D, d M Y H:i:s', $lastModified ) . ' GMT; length=5202',
+                                       true ],
+                       // @todo Should we fix this behavior to match the spec?  Probably no reason to.
+                       'If-Modified-Since not per spec but we accept it anyway because strtotime does' =>
+                               [ $lastModified, "@$lastModified", true ],
+                       '$wgCachePages = false' =>
+                               [ $lastModified, $lastModified, false, [ 'CachePages' => false ] ],
+                       '$wgCacheEpoch' =>
+                               [ $lastModified, $lastModified, false,
+                                       [ 'CacheEpoch' => wfTimestamp( TS_MW, $lastModified + 1 ) ] ],
+                       'Recently-touched user' =>
+                               [ $lastModified, $lastModified, false, [],
+                               function ( $op ) {
+                                       $op->getContext()->setUser( $this->getTestUser()->getUser() );
+                               } ],
+                       'After Squid expiry' =>
+                               [ $lastModified, $lastModified, false,
+                                       [ 'UseSquid' => true, 'SquidMaxage' => 3599 ] ],
+                       'Hook allows cache use' =>
+                               [ $lastModified + 1, $lastModified, true, [],
+                               function ( $op, $that ) {
+                                       $that->setTemporaryHook( 'OutputPageCheckLastModified',
+                                               function ( &$modifiedTimes ) {
+                                                       $modifiedTimes = [ 1 ];
+                                               }
+                                       );
+                               } ],
+                       'Hooks prohibits cache use' =>
+                               [ $lastModified, $lastModified, false, [],
+                               function ( $op, $that ) {
+                                       $that->setTemporaryHook( 'OutputPageCheckLastModified',
+                                               function ( &$modifiedTimes ) {
+                                                       $modifiedTimes = [ max( $modifiedTimes ) + 1 ];
+                                               }
+                                       );
+                               } ],
+               ];
        }
 
        /**
-        * Tests print requests
-        * @covers OutputPage::transformCssMedia
+        * @dataProvider provideCdnCacheEpoch
+        *
+        * @covers OutputPage::getCdnCacheEpoch
         */
-       public function testPrintRequests() {
-               $this->assertTransformCssMediaCase( [
-                       'printableQuery' => '1',
-                       'media' => 'screen',
-                       'expectedReturn' => null,
-                       'message' => 'On printable request, screen returns null'
-               ] );
-
-               $this->assertTransformCssMediaCase( [
-                       'printableQuery' => '1',
-                       'media' => self::SCREEN_MEDIA_QUERY,
-                       'expectedReturn' => null,
-                       'message' => 'On printable request, screen media query returns null'
-               ] );
-
-               $this->assertTransformCssMediaCase( [
-                       'printableQuery' => '1',
-                       'media' => self::SCREEN_ONLY_MEDIA_QUERY,
-                       'expectedReturn' => null,
-                       'message' => 'On printable request, screen media query with only returns null'
-               ] );
+       public function testCdnCacheEpoch( $params ) {
+               $out = TestingAccessWrapper::newFromObject( $this->newInstance() );
+               $reqTime = strtotime( $params['reqTime'] );
+               $pageTime = strtotime( $params['pageTime'] );
+               $actual = max( $pageTime, $out->getCdnCacheEpoch( $reqTime, $params['maxAge'] ) );
 
-               $this->assertTransformCssMediaCase( [
-                       'printableQuery' => '1',
-                       'media' => 'print',
-                       'expectedReturn' => '',
-                       'message' => 'On printable request, media print returns empty string'
-               ] );
+               $this->assertEquals(
+                       $params['expect'],
+                       gmdate( DateTime::ATOM, $actual ),
+                       'cdn epoch'
+               );
        }
 
        public static function provideCdnCacheEpoch() {
@@ -149,229 +424,418 @@ class OutputPageTest extends MediaWikiTestCase {
                ];
        }
 
+       // @todo How to test setLastModified?
+
        /**
-        * @dataProvider provideCdnCacheEpoch
-        * @covers OutputPage::getCdnCacheEpoch
+        * @covers OutputPage::setRobotPolicy
+        * @covers OutputPage::getHeadLinksArray
         */
-       public function testCdnCacheEpoch( $params ) {
-               $out = TestingAccessWrapper::newFromObject( $this->newInstance() );
-               $reqTime = strtotime( $params['reqTime'] );
-               $pageTime = strtotime( $params['pageTime'] );
-               $actual = max( $pageTime, $out->getCdnCacheEpoch( $reqTime, $params['maxAge'] ) );
+       public function testSetRobotPolicy() {
+               $op = $this->newInstance();
+               $op->setRobotPolicy( 'noindex, nofollow' );
 
-               $this->assertEquals(
-                       $params['expect'],
-                       gmdate( DateTime::ATOM, $actual ),
-                       'cdn epoch'
+               $links = $op->getHeadLinksArray();
+               $this->assertContains( '<meta name="robots" content="noindex,nofollow"/>', $links );
+       }
+
+       /**
+        * @covers OutputPage::setIndexPolicy
+        * @covers OutputPage::setFollowPolicy
+        * @covers OutputPage::getHeadLinksArray
+        */
+       public function testSetIndexFollowPolicies() {
+               $op = $this->newInstance();
+               $op->setIndexPolicy( 'noindex' );
+               $op->setFollowPolicy( 'nofollow' );
+
+               $links = $op->getHeadLinksArray();
+               $this->assertContains( '<meta name="robots" content="noindex,nofollow"/>', $links );
+       }
+
+       // @todo mPageTitleActionText has done nothing and has no callers for a long time:
+       //
+       //   * e4d21170 inadvertently made it do nothing (Apr 2009)
+       //   * 10ecfcb0/cadc951d removed the dead code that would have at least indicated what it was
+       //   supposed to do (Nov 2010)
+       //   * 9e230f30/2d045fa1 removed from history pages because it did nothing (Oct/Aug 2011)
+       //   * e275ea28 removed from articles (Oct 2011)
+       //   * ae45908c removed from EditPage (Oct 2011)
+       //
+       // Nice if we had had tests so these things couldn't happen by mistake, right?!
+       //
+       // https://phabricator.wikimedia.org/T200643
+
+       private function extractHTMLTitle( OutputPage $op ) {
+               $html = $op->headElement( $op->getContext()->getSkin() );
+
+               // OutputPage should always output the title in a nice format such that regexes will work
+               // fine.  If it doesn't, we'll fail the tests.
+               preg_match_all( '!<title>(.*?)</title>!', $html, $matches );
+
+               $this->assertLessThanOrEqual( 1, count( $matches[1] ), 'More than one <title>!' );
+
+               if ( !count( $matches[1] ) ) {
+                       return null;
+               }
+
+               return $matches[1][0];
+       }
+
+       /**
+        * Shorthand for getting the text of a message, in content language.
+        */
+       private static function getMsgText( $op, ...$msgParams ) {
+               return $op->msg( ...$msgParams )->inContentLanguage()->text();
+       }
+
+       /**
+        * @covers OutputPage::setHTMLTitle
+        * @covers OutputPage::getHTMLTitle
+        */
+       public function testHTMLTitle() {
+               $op = $this->newInstance();
+
+               // Default
+               $this->assertSame( '', $op->getHTMLTitle() );
+               $this->assertSame( '', $op->getPageTitle() );
+               $this->assertSame(
+                       $this->getMsgText( $op, 'pagetitle', '' ),
+                       $this->extractHTMLTitle( $op )
                );
+
+               // Set to string
+               $op->setHTMLTitle( 'Potatoes will eat me' );
+
+               $this->assertSame( 'Potatoes will eat me', $op->getHTMLTitle() );
+               $this->assertSame( 'Potatoes will eat me', $this->extractHTMLTitle( $op ) );
+               // Shouldn't have changed the page title
+               $this->assertSame( '', $op->getPageTitle() );
+
+               // Set to message
+               $msg = $op->msg( 'mainpage' );
+
+               $op->setHTMLTitle( $msg );
+               $this->assertSame( $msg->text(), $op->getHTMLTitle() );
+               $this->assertSame( $msg->text(), $this->extractHTMLTitle( $op ) );
+               $this->assertSame( '', $op->getPageTitle() );
        }
 
        /**
-        * Tests screen requests, without either query parameter set
-        * @covers OutputPage::transformCssMedia
+        * @covers OutputPage::setRedirectedFrom
         */
-       public function testScreenRequests() {
-               $this->assertTransformCssMediaCase( [
-                       'media' => 'screen',
-                       'expectedReturn' => 'screen',
-                       'message' => 'On screen request, screen media type is preserved'
-               ] );
+       public function testSetRedirectedFrom() {
+               $op = $this->newInstance();
 
-               $this->assertTransformCssMediaCase( [
-                       'media' => 'handheld',
-                       'expectedReturn' => 'handheld',
-                       'message' => 'On screen request, handheld media type is preserved'
-               ] );
+               $op->setRedirectedFrom( Title::newFromText( 'Talk:Some page' ) );
+               $this->assertSame( 'Talk:Some_page', $op->getJSVars()['wgRedirectedFrom'] );
+       }
 
-               $this->assertTransformCssMediaCase( [
-                       'media' => self::SCREEN_MEDIA_QUERY,
-                       'expectedReturn' => self::SCREEN_MEDIA_QUERY,
-                       'message' => 'On screen request, screen media query is preserved.'
-               ] );
+       /**
+        * @covers OutputPage::setPageTitle
+        * @covers OutputPage::getPageTitle
+        */
+       public function testPageTitle() {
+               // We don't test the actual HTML output anywhere, because that's up to the skin.
+               $op = $this->newInstance();
 
-               $this->assertTransformCssMediaCase( [
-                       'media' => self::SCREEN_ONLY_MEDIA_QUERY,
-                       'expectedReturn' => self::SCREEN_ONLY_MEDIA_QUERY,
-                       'message' => 'On screen request, screen media query with only is preserved.'
-               ] );
+               // Test default
+               $this->assertSame( '', $op->getPageTitle() );
+               $this->assertSame( '', $op->getHTMLTitle() );
 
-               $this->assertTransformCssMediaCase( [
-                       'media' => 'print',
-                       'expectedReturn' => 'print',
-                       'message' => 'On screen request, print media type is preserved'
-               ] );
+               // Test set to plain text
+               $op->setPageTitle( 'foobar' );
+
+               $this->assertSame( 'foobar', $op->getPageTitle() );
+               // HTML title should change as well
+               $this->assertSame( $this->getMsgText( $op, 'pagetitle', 'foobar' ), $op->getHTMLTitle() );
+
+               // Test set to text with good and bad HTML.  We don't try to be comprehensive here, that
+               // belongs in Sanitizer tests.
+               $op->setPageTitle( '<script>a</script>&amp;<i>b</i>' );
+
+               $this->assertSame( '&lt;script&gt;a&lt;/script&gt;&amp;<i>b</i>', $op->getPageTitle() );
+               $this->assertSame(
+                       $this->getMsgText( $op, 'pagetitle', '<script>a</script>&b' ),
+                       $op->getHTMLTitle()
+               );
+
+               // Test set to message
+               $text = $this->getMsgText( $op, 'mainpage' );
+
+               $op->setPageTitle( $op->msg( 'mainpage' )->inContentLanguage() );
+               $this->assertSame( $text, $op->getPageTitle() );
+               $this->assertSame( $this->getMsgText( $op, 'pagetitle', $text ), $op->getHTMLTitle() );
        }
 
        /**
-        * Tests handheld behavior
-        * @covers OutputPage::transformCssMedia
+        * @covers OutputPage::setTitle
         */
-       public function testHandheld() {
-               $this->assertTransformCssMediaCase( [
-                       'handheldQuery' => '1',
-                       'media' => 'handheld',
-                       'expectedReturn' => '',
-                       'message' => 'On request with handheld querystring and media is handheld, returns empty string'
+       public function testSetTitle() {
+               $op = $this->newInstance();
+
+               $this->assertSame( 'My test page', $op->getTitle()->getPrefixedText() );
+
+               $op->setTitle( Title::newFromText( 'Another test page' ) );
+
+               $this->assertSame( 'Another test page', $op->getTitle()->getPrefixedText() );
+       }
+
+       /**
+        * @covers OutputPage::setSubtitle
+        * @covers OutputPage::clearSubtitle
+        * @covers OutputPage::addSubtitle
+        * @covers OutputPage::getSubtitle
+        */
+       public function testSubtitle() {
+               $op = $this->newInstance();
+
+               $this->assertSame( '', $op->getSubtitle() );
+
+               $op->addSubtitle( '<b>foo</b>' );
+
+               $this->assertSame( '<b>foo</b>', $op->getSubtitle() );
+
+               $op->addSubtitle( $op->msg( 'mainpage' )->inContentLanguage() );
+
+               $this->assertSame(
+                       "<b>foo</b><br />\n\t\t\t\t" . $this->getMsgText( $op, 'mainpage' ),
+                       $op->getSubtitle()
+               );
+
+               $op->setSubtitle( 'There can be only one' );
+
+               $this->assertSame( 'There can be only one', $op->getSubtitle() );
+
+               $op->clearSubtitle();
+
+               $this->assertSame( '', $op->getSubtitle() );
+       }
+
+       /**
+        * @dataProvider provideBacklinkSubtitle
+        *
+        * @covers OutputPage::buildBacklinkSubtitle
+        */
+       public function testBuildBacklinkSubtitle( Title $title, $query, $contains, $notContains ) {
+               $this->editPage( 'Page 1', '' );
+               $this->editPage( 'Page 2', '#REDIRECT [[Page 1]]' );
+
+               $str = OutputPage::buildBacklinkSubtitle( $title, $query )->text();
+
+               foreach ( $contains as $substr ) {
+                       $this->assertContains( $substr, $str );
+               }
+
+               foreach ( $notContains as $substr ) {
+                       $this->assertNotContains( $substr, $str );
+               }
+       }
+
+       /**
+        * @dataProvider provideBacklinkSubtitle
+        *
+        * @covers OutputPage::addBacklinkSubtitle
+        * @covers OutputPage::getSubtitle
+        */
+       public function testAddBacklinkSubtitle( Title $title, $query, $contains, $notContains ) {
+               $this->editPage( 'Page 1', '' );
+               $this->editPage( 'Page 2', '#REDIRECT [[Page 1]]' );
+
+               $op = $this->newInstance();
+               $op->addBacklinkSubtitle( $title, $query );
+
+               $str = $op->getSubtitle();
+
+               foreach ( $contains as $substr ) {
+                       $this->assertContains( $substr, $str );
+               }
+
+               foreach ( $notContains as $substr ) {
+                       $this->assertNotContains( $substr, $str );
+               }
+       }
+
+       public function provideBacklinkSubtitle() {
+               $page1 = Title::newFromText( 'Page 1' );
+               $page2 = Title::newFromText( 'Page 2' );
+
+               return [
+                       [ $page1, [], [ 'Page 1' ], [ 'redirect', 'Page 2' ] ],
+                       [ $page2, [], [ 'redirect=no' ], [ 'Page 1' ] ],
+                       [ $page1, [ 'action' => 'edit' ], [ 'action=edit' ], [] ],
+                       // @todo Anything else to test?
+               ];
+       }
+
+       /**
+        * @covers OutputPage::addCategoryLinks
+        * @covers OutputPage::getCategories
+        */
+       public function testGetCategories() {
+               $fakeResultWrapper = new FakeResultWrapper( [
+                       (object)[
+                               'pp_value' => 1,
+                               'page_title' => 'Test'
+                       ],
+                       (object)[
+                               'page_title' => 'Test2'
+                       ]
                ] );
+               $op = $this->getMockBuilder( OutputPage::class )
+                       ->setConstructorArgs( [ new RequestContext() ] )
+                       ->setMethods( [ 'addCategoryLinksToLBAndGetResult' ] )
+                       ->getMock();
+               $op->expects( $this->any() )
+                       ->method( 'addCategoryLinksToLBAndGetResult' )
+                       ->will( $this->returnValue( $fakeResultWrapper ) );
 
-               $this->assertTransformCssMediaCase( [
-                       'handheldQuery' => '1',
-                       'media' => 'screen',
-                       'expectedReturn' => null,
-                       'message' => 'On request with handheld querystring and media is screen, returns null'
+               $op->addCategoryLinks( [
+                       'Test' => 'Test',
+                       'Test2' => 'Test2',
                ] );
+               $this->assertEquals( [ 0 => 'Test', '1' => 'Test2' ], $op->getCategories() );
+               $this->assertEquals( [ 0 => 'Test2' ], $op->getCategories( 'normal' ) );
+               $this->assertEquals( [ 0 => 'Test' ], $op->getCategories( 'hidden' ) );
        }
 
-       public static function provideTransformFilePath() {
-               $baseDir = dirname( __DIR__ ) . '/data/media';
+       /**
+        * @covers OutputPage::haveCacheVaryCookies
+        */
+       public function testHaveCacheVaryCookies() {
+               $request = new FauxRequest();
+               $context = new RequestContext();
+               $context->setRequest( $request );
+               $op = new OutputPage( $context );
+
+               // No cookies are set.
+               $this->assertFalse( $op->haveCacheVaryCookies() );
+
+               // 'Token' is present but empty, so it shouldn't count.
+               $request->setCookie( 'Token', '' );
+               $this->assertFalse( $op->haveCacheVaryCookies() );
+
+               // 'Token' present and nonempty.
+               $request->setCookie( 'Token', '123' );
+               $this->assertTrue( $op->haveCacheVaryCookies() );
+       }
+
+       /**
+        * @dataProvider provideVaryHeaders
+        *
+        * @covers OutputPage::addVaryHeader
+        * @covers OutputPage::getVaryHeader
+        * @covers OutputPage::getKeyHeader
+        */
+       public function testVaryHeaders( $calls, $vary, $key ) {
+               // get rid of default Vary fields
+               $op = $this->getMockBuilder( OutputPage::class )
+                       ->setConstructorArgs( [ new RequestContext() ] )
+                       ->setMethods( [ 'getCacheVaryCookies' ] )
+                       ->getMock();
+               $op->expects( $this->any() )
+                       ->method( 'getCacheVaryCookies' )
+                       ->will( $this->returnValue( [] ) );
+               TestingAccessWrapper::newFromObject( $op )->mVaryHeader = [];
+
+               foreach ( $calls as $call ) {
+                       call_user_func_array( [ $op, 'addVaryHeader' ], $call );
+               }
+               $this->assertEquals( $vary, $op->getVaryHeader(), 'Vary:' );
+               $this->assertEquals( $key, $op->getKeyHeader(), 'Key:' );
+       }
+
+       public function provideVaryHeaders() {
+               // note: getKeyHeader() automatically adds Vary: Cookie
                return [
-                       // File that matches basePath, and exists. Hash found and appended.
-                       [
-                               'baseDir' => $baseDir, 'basePath' => '/w',
-                               '/w/test.jpg',
-                               '/w/test.jpg?edcf2'
-                       ],
-                       // File that matches basePath, but not found on disk. Empty query.
-                       [
-                               'baseDir' => $baseDir, 'basePath' => '/w',
-                               '/w/unknown.png',
-                               '/w/unknown.png?'
-                       ],
-                       // File not matching basePath. Ignored.
-                       [
-                               'baseDir' => $baseDir, 'basePath' => '/w',
-                               '/files/test.jpg'
-                       ],
-                       // Empty string. Ignored.
-                       [
-                               'baseDir' => $baseDir, 'basePath' => '/w',
-                               '',
-                               ''
-                       ],
-                       // Similar path, but with domain component. Ignored.
-                       [
-                               'baseDir' => $baseDir, 'basePath' => '/w',
-                               '//example.org/w/test.jpg'
-                       ],
-                       [
-                               'baseDir' => $baseDir, 'basePath' => '/w',
-                               'https://example.org/w/test.jpg'
-                       ],
-                       // Unrelated path with domain component. Ignored.
-                       [
-                               'baseDir' => $baseDir, 'basePath' => '/w',
-                               'https://example.org/files/test.jpg'
+                       [ // single header
+                               [
+                                       [ 'Cookie' ],
+                               ],
+                               'Vary: Cookie',
+                               'Key: Cookie',
                        ],
-                       [
-                               'baseDir' => $baseDir, 'basePath' => '/w',
-                               '//example.org/files/test.jpg'
+                       [ // non-unique headers
+                               [
+                                       [ 'Cookie' ],
+                                       [ 'Accept-Language' ],
+                                       [ 'Cookie' ],
+                               ],
+                               'Vary: Cookie, Accept-Language',
+                               'Key: Cookie,Accept-Language',
                        ],
-                       // Unrelated path with domain, and empty base path (root mw install). Ignored.
-                       [
-                               'baseDir' => $baseDir, 'basePath' => '',
-                               'https://example.org/files/test.jpg'
+                       [ // two headers with single options
+                               [
+                                       [ 'Cookie', [ 'param=phpsessid' ] ],
+                                       [ 'Accept-Language', [ 'substr=en' ] ],
+                               ],
+                               'Vary: Cookie, Accept-Language',
+                               'Key: Cookie;param=phpsessid,Accept-Language;substr=en',
                        ],
-                       [
-                               'baseDir' => $baseDir, 'basePath' => '',
-                               // T155310
-                               '//example.org/files/test.jpg'
+                       [ // one header with multiple options
+                               [
+                                       [ 'Cookie', [ 'param=phpsessid', 'param=userId' ] ],
+                               ],
+                               'Vary: Cookie',
+                               'Key: Cookie;param=phpsessid;param=userId',
                        ],
-                       // Check UploadPath before ResourceBasePath (T155146)
-                       [
-                               'baseDir' => dirname( $baseDir ), 'basePath' => '',
-                               'uploadDir' => $baseDir, 'uploadPath' => '/images',
-                               '/images/test.jpg',
-                               '/images/test.jpg?edcf2'
+                       [ // Duplicate option
+                               [
+                                       [ 'Cookie', [ 'param=phpsessid' ] ],
+                                       [ 'Cookie', [ 'param=phpsessid' ] ],
+                                       [ 'Accept-Language', [ 'substr=en', 'substr=en' ] ],
+                               ],
+                               'Vary: Cookie, Accept-Language',
+                               'Key: Cookie;param=phpsessid,Accept-Language;substr=en',
+                       ],
+                       [ // Same header, different options
+                               [
+                                       [ 'Cookie', [ 'param=phpsessid' ] ],
+                                       [ 'Cookie', [ 'param=userId' ] ],
+                               ],
+                               'Vary: Cookie',
+                               'Key: Cookie;param=phpsessid;param=userId',
                        ],
                ];
        }
 
        /**
-        * @dataProvider provideTransformFilePath
-        * @covers OutputPage::transformFilePath
-        * @covers OutputPage::transformResourcePath
+        * @dataProvider provideLinkHeaders
+        *
+        * @covers OutputPage::addLinkHeader
+        * @covers OutputPage::getLinkHeader
         */
-       public function testTransformResourcePath( $baseDir, $basePath, $uploadDir = null,
-               $uploadPath = null, $path = null, $expected = null
-       ) {
-               if ( $path === null ) {
-                       // Skip optional $uploadDir and $uploadPath
-                       $path = $uploadDir;
-                       $expected = $uploadPath;
-                       $uploadDir = "$baseDir/images";
-                       $uploadPath = "$basePath/images";
-               }
-               $this->setMwGlobals( 'IP', $baseDir );
-               $conf = new HashConfig( [
-                       'ResourceBasePath' => $basePath,
-                       'UploadDirectory' => $uploadDir,
-                       'UploadPath' => $uploadPath,
-               ] );
+       public function testLinkHeaders( $headers, $result ) {
+               $op = $this->newInstance();
 
-               Wikimedia\suppressWarnings();
-               $actual = OutputPage::transformResourcePath( $conf, $path );
-               Wikimedia\restoreWarnings();
+               foreach ( $headers as $header ) {
+                       $op->addLinkHeader( $header );
+               }
 
-               $this->assertEquals( $expected ?: $path, $actual );
+               $this->assertEquals( $result, $op->getLinkHeader() );
        }
 
-       public static function provideMakeResourceLoaderLink() {
-               // phpcs:disable Generic.Files.LineLength
+       public function provideLinkHeaders() {
                return [
-                       // Single only=scripts load
-                       [
-                               [ 'test.foo', ResourceLoaderModule::TYPE_SCRIPTS ],
-                               "<script nonce=\"secret\">(window.RLQ=window.RLQ||[]).push(function(){"
-                                       . 'mw.loader.load("http://127.0.0.1:8080/w/load.php?debug=false\u0026lang=en\u0026modules=test.foo\u0026only=scripts\u0026skin=fallback");'
-                                       . "});</script>"
-                       ],
-                       // Multiple only=styles load
-                       [
-                               [ [ 'test.baz', 'test.foo', 'test.bar' ], ResourceLoaderModule::TYPE_STYLES ],
-
-                               '<link rel="stylesheet" href="http://127.0.0.1:8080/w/load.php?debug=false&amp;lang=en&amp;modules=test.bar%2Cbaz%2Cfoo&amp;only=styles&amp;skin=fallback"/>'
-                       ],
-                       // Private embed (only=scripts)
                        [
-                               [ 'test.quux', ResourceLoaderModule::TYPE_SCRIPTS ],
-                               "<script nonce=\"secret\">(window.RLQ=window.RLQ||[]).push(function(){"
-                                       . "mw.test.baz({token:123});\nmw.loader.state({\"test.quux\":\"ready\"});"
-                                       . "});</script>"
-                       ],
-                       // Load private module (combined)
-                       [
-                               [ 'test.quux', ResourceLoaderModule::TYPE_COMBINED ],
-                               "<script nonce=\"secret\">(window.RLQ=window.RLQ||[]).push(function(){"
-                                       . "mw.loader.implement(\"test.quux@1ev0ijv\",function($,jQuery,require,module){"
-                                       . "mw.test.baz({token:123});},{\"css\":[\".mw-icon{transition:none}"
-                                       . "\"]});});</script>"
-                       ],
-                       // Load no modules
-                       [
-                               [ [], ResourceLoaderModule::TYPE_COMBINED ],
-                               '',
+                               [],
+                               false
                        ],
-                       // noscript group
                        [
-                               [ 'test.noscript', ResourceLoaderModule::TYPE_STYLES ],
-                               '<noscript><link rel="stylesheet" href="http://127.0.0.1:8080/w/load.php?debug=false&amp;lang=en&amp;modules=test.noscript&amp;only=styles&amp;skin=fallback"/></noscript>'
+                               [ '<https://foo/bar.jpg>;rel=preload;as=image' ],
+                               'Link: <https://foo/bar.jpg>;rel=preload;as=image',
                        ],
-                       // Load two modules in separate groups
                        [
-                               [ [ 'test.group.foo', 'test.group.bar' ], ResourceLoaderModule::TYPE_COMBINED ],
-                               "<script nonce=\"secret\">(window.RLQ=window.RLQ||[]).push(function(){"
-                                       . 'mw.loader.load("http://127.0.0.1:8080/w/load.php?debug=false\u0026lang=en\u0026modules=test.group.bar\u0026skin=fallback");'
-                                       . 'mw.loader.load("http://127.0.0.1:8080/w/load.php?debug=false\u0026lang=en\u0026modules=test.group.foo\u0026skin=fallback");'
-                                       . "});</script>"
+                               [ '<https://foo/bar.jpg>;rel=preload;as=image','<https://foo/baz.jpg>;rel=preload;as=image' ],
+                               'Link: <https://foo/bar.jpg>;rel=preload;as=image,<https://foo/baz.jpg>;rel=preload;as=image',
                        ],
                ];
-               // phpcs:enable
        }
 
        /**
         * See ResourceLoaderClientHtmlTest for full coverage.
         *
         * @dataProvider provideMakeResourceLoaderLink
+        *
         * @covers OutputPage::makeResourceLoaderLink
         */
        public function testMakeResourceLoaderLink( $args, $expectedHtml ) {
@@ -428,38 +892,54 @@ class OutputPageTest extends MediaWikiTestCase {
                $this->assertEquals( $expectedHtml, $actualHtml );
        }
 
-       public static function provideBuildExemptModules() {
+       public static function provideMakeResourceLoaderLink() {
                // phpcs:disable Generic.Files.LineLength
                return [
-                       'empty' => [
-                               'exemptStyleModules' => [],
-                               '<meta name="ResourceLoaderDynamicStyles" content=""/>',
+                       // Single only=scripts load
+                       [
+                               [ 'test.foo', ResourceLoaderModule::TYPE_SCRIPTS ],
+                               "<script nonce=\"secret\">(window.RLQ=window.RLQ||[]).push(function(){"
+                                       . 'mw.loader.load("http://127.0.0.1:8080/w/load.php?debug=false\u0026lang=en\u0026modules=test.foo\u0026only=scripts\u0026skin=fallback");'
+                                       . "});</script>"
                        ],
-                       'empty sets' => [
-                               'exemptStyleModules' => [ 'site' => [], 'noscript' => [], 'private' => [], 'user' => [] ],
-                               '<meta name="ResourceLoaderDynamicStyles" content=""/>',
+                       // Multiple only=styles load
+                       [
+                               [ [ 'test.baz', 'test.foo', 'test.bar' ], ResourceLoaderModule::TYPE_STYLES ],
+
+                               '<link rel="stylesheet" href="http://127.0.0.1:8080/w/load.php?debug=false&amp;lang=en&amp;modules=test.bar%2Cbaz%2Cfoo&amp;only=styles&amp;skin=fallback"/>'
                        ],
-                       'default logged-out' => [
-                               'exemptStyleModules' => [ 'site' => [ 'site.styles' ] ],
-                               '<meta name="ResourceLoaderDynamicStyles" content=""/>' . "\n" .
-                               '<link rel="stylesheet" href="/w/load.php?debug=false&amp;lang=en&amp;modules=site.styles&amp;only=styles&amp;skin=fallback"/>',
+                       // Private embed (only=scripts)
+                       [
+                               [ 'test.quux', ResourceLoaderModule::TYPE_SCRIPTS ],
+                               "<script nonce=\"secret\">(window.RLQ=window.RLQ||[]).push(function(){"
+                                       . "mw.test.baz({token:123});\nmw.loader.state({\"test.quux\":\"ready\"});"
+                                       . "});</script>"
                        ],
-                       'default logged-in' => [
-                               'exemptStyleModules' => [ 'site' => [ 'site.styles' ], 'user' => [ 'user.styles' ] ],
-                               '<meta name="ResourceLoaderDynamicStyles" content=""/>' . "\n" .
-                               '<link rel="stylesheet" href="/w/load.php?debug=false&amp;lang=en&amp;modules=site.styles&amp;only=styles&amp;skin=fallback"/>' . "\n" .
-                               '<link rel="stylesheet" href="/w/load.php?debug=false&amp;lang=en&amp;modules=user.styles&amp;only=styles&amp;skin=fallback&amp;version=1e9z0ox"/>',
+                       // Load private module (combined)
+                       [
+                               [ 'test.quux', ResourceLoaderModule::TYPE_COMBINED ],
+                               "<script nonce=\"secret\">(window.RLQ=window.RLQ||[]).push(function(){"
+                                       . "mw.loader.implement(\"test.quux@1ev0ijv\",function($,jQuery,require,module){"
+                                       . "mw.test.baz({token:123});},{\"css\":[\".mw-icon{transition:none}"
+                                       . "\"]});});</script>"
                        ],
-                       'custom modules' => [
-                               'exemptStyleModules' => [
-                                       'site' => [ 'site.styles', 'example.site.a', 'example.site.b' ],
-                                       'user' => [ 'user.styles', 'example.user' ],
-                               ],
-                               '<meta name="ResourceLoaderDynamicStyles" content=""/>' . "\n" .
-                               '<link rel="stylesheet" href="/w/load.php?debug=false&amp;lang=en&amp;modules=example.site.a%2Cb&amp;only=styles&amp;skin=fallback"/>' . "\n" .
-                               '<link rel="stylesheet" href="/w/load.php?debug=false&amp;lang=en&amp;modules=site.styles&amp;only=styles&amp;skin=fallback"/>' . "\n" .
-                               '<link rel="stylesheet" href="/w/load.php?debug=false&amp;lang=en&amp;modules=example.user&amp;only=styles&amp;skin=fallback&amp;version=0a56zyi"/>' . "\n" .
-                               '<link rel="stylesheet" href="/w/load.php?debug=false&amp;lang=en&amp;modules=user.styles&amp;only=styles&amp;skin=fallback&amp;version=1e9z0ox"/>',
+                       // Load no modules
+                       [
+                               [ [], ResourceLoaderModule::TYPE_COMBINED ],
+                               '',
+                       ],
+                       // noscript group
+                       [
+                               [ 'test.noscript', ResourceLoaderModule::TYPE_STYLES ],
+                               '<noscript><link rel="stylesheet" href="http://127.0.0.1:8080/w/load.php?debug=false&amp;lang=en&amp;modules=test.noscript&amp;only=styles&amp;skin=fallback"/></noscript>'
+                       ],
+                       // Load two modules in separate groups
+                       [
+                               [ [ 'test.group.foo', 'test.group.bar' ], ResourceLoaderModule::TYPE_COMBINED ],
+                               "<script nonce=\"secret\">(window.RLQ=window.RLQ||[]).push(function(){"
+                                       . 'mw.loader.load("http://127.0.0.1:8080/w/load.php?debug=false\u0026lang=en\u0026modules=test.group.bar\u0026skin=fallback");'
+                                       . 'mw.loader.load("http://127.0.0.1:8080/w/load.php?debug=false\u0026lang=en\u0026modules=test.group.foo\u0026skin=fallback");'
+                                       . "});</script>"
                        ],
                ];
                // phpcs:enable
@@ -467,6 +947,7 @@ class OutputPageTest extends MediaWikiTestCase {
 
        /**
         * @dataProvider provideBuildExemptModules
+        *
         * @covers OutputPage::buildExemptModules
         */
        public function testBuildExemptModules( array $exemptStyleModules, $expect ) {
@@ -482,14 +963,14 @@ class OutputPageTest extends MediaWikiTestCase {
                $ctx = new RequestContext();
                $ctx->setSkin( SkinFactory::getDefaultInstance()->makeSkin( 'fallback' ) );
                $ctx->setLanguage( 'en' );
-               $outputPage = $this->getMockBuilder( OutputPage::class )
+               $op = $this->getMockBuilder( OutputPage::class )
                        ->setConstructorArgs( [ $ctx ] )
                        ->setMethods( [ 'buildCssLinksArray' ] )
                        ->getMock();
-               $outputPage->expects( $this->any() )
+               $op->expects( $this->any() )
                        ->method( 'buildCssLinksArray' )
                        ->willReturn( [] );
-               $rl = $outputPage->getResourceLoader();
+               $rl = $op->getResourceLoader();
                $rl->setMessageBlobStore( new NullMessageBlobStore() );
 
                // Register custom modules
@@ -499,174 +980,269 @@ class OutputPageTest extends MediaWikiTestCase {
                        'example.user' => new ResourceLoaderTestModule( [ 'group' => 'user' ] ),
                ] );
 
-               $outputPage = TestingAccessWrapper::newFromObject( $outputPage );
-               $outputPage->rlExemptStyleModules = $exemptStyleModules;
+               $op = TestingAccessWrapper::newFromObject( $op );
+               $op->rlExemptStyleModules = $exemptStyleModules;
                $this->assertEquals(
                        $expect,
-                       strval( $outputPage->buildExemptModules() )
+                       strval( $op->buildExemptModules() )
                );
        }
 
+       public static function provideBuildExemptModules() {
+               // phpcs:disable Generic.Files.LineLength
+               return [
+                       'empty' => [
+                               'exemptStyleModules' => [],
+                               '<meta name="ResourceLoaderDynamicStyles" content=""/>',
+                       ],
+                       'empty sets' => [
+                               'exemptStyleModules' => [ 'site' => [], 'noscript' => [], 'private' => [], 'user' => [] ],
+                               '<meta name="ResourceLoaderDynamicStyles" content=""/>',
+                       ],
+                       'default logged-out' => [
+                               'exemptStyleModules' => [ 'site' => [ 'site.styles' ] ],
+                               '<meta name="ResourceLoaderDynamicStyles" content=""/>' . "\n" .
+                               '<link rel="stylesheet" href="/w/load.php?debug=false&amp;lang=en&amp;modules=site.styles&amp;only=styles&amp;skin=fallback"/>',
+                       ],
+                       'default logged-in' => [
+                               'exemptStyleModules' => [ 'site' => [ 'site.styles' ], 'user' => [ 'user.styles' ] ],
+                               '<meta name="ResourceLoaderDynamicStyles" content=""/>' . "\n" .
+                               '<link rel="stylesheet" href="/w/load.php?debug=false&amp;lang=en&amp;modules=site.styles&amp;only=styles&amp;skin=fallback"/>' . "\n" .
+                               '<link rel="stylesheet" href="/w/load.php?debug=false&amp;lang=en&amp;modules=user.styles&amp;only=styles&amp;skin=fallback&amp;version=1e9z0ox"/>',
+                       ],
+                       'custom modules' => [
+                               'exemptStyleModules' => [
+                                       'site' => [ 'site.styles', 'example.site.a', 'example.site.b' ],
+                                       'user' => [ 'user.styles', 'example.user' ],
+                               ],
+                               '<meta name="ResourceLoaderDynamicStyles" content=""/>' . "\n" .
+                               '<link rel="stylesheet" href="/w/load.php?debug=false&amp;lang=en&amp;modules=example.site.a%2Cb&amp;only=styles&amp;skin=fallback"/>' . "\n" .
+                               '<link rel="stylesheet" href="/w/load.php?debug=false&amp;lang=en&amp;modules=site.styles&amp;only=styles&amp;skin=fallback"/>' . "\n" .
+                               '<link rel="stylesheet" href="/w/load.php?debug=false&amp;lang=en&amp;modules=example.user&amp;only=styles&amp;skin=fallback&amp;version=0a56zyi"/>' . "\n" .
+                               '<link rel="stylesheet" href="/w/load.php?debug=false&amp;lang=en&amp;modules=user.styles&amp;only=styles&amp;skin=fallback&amp;version=1e9z0ox"/>',
+                       ],
+               ];
+               // phpcs:enable
+       }
+
        /**
-        * @dataProvider provideVaryHeaders
-        * @covers OutputPage::addVaryHeader
-        * @covers OutputPage::getVaryHeader
-        * @covers OutputPage::getKeyHeader
+        * @dataProvider provideTransformFilePath
+        * @covers OutputPage::transformFilePath
+        * @covers OutputPage::transformResourcePath
         */
-       public function testVaryHeaders( $calls, $vary, $key ) {
-               // get rid of default Vary fields
-               $outputPage = $this->getMockBuilder( OutputPage::class )
-                       ->setConstructorArgs( [ new RequestContext() ] )
-                       ->setMethods( [ 'getCacheVaryCookies' ] )
-                       ->getMock();
-               $outputPage->expects( $this->any() )
-                       ->method( 'getCacheVaryCookies' )
-                       ->will( $this->returnValue( [] ) );
-               TestingAccessWrapper::newFromObject( $outputPage )->mVaryHeader = [];
-
-               foreach ( $calls as $call ) {
-                       call_user_func_array( [ $outputPage, 'addVaryHeader' ], $call );
+       public function testTransformResourcePath( $baseDir, $basePath, $uploadDir = null,
+               $uploadPath = null, $path = null, $expected = null
+       ) {
+               if ( $path === null ) {
+                       // Skip optional $uploadDir and $uploadPath
+                       $path = $uploadDir;
+                       $expected = $uploadPath;
+                       $uploadDir = "$baseDir/images";
+                       $uploadPath = "$basePath/images";
                }
-               $this->assertEquals( $vary, $outputPage->getVaryHeader(), 'Vary:' );
-               $this->assertEquals( $key, $outputPage->getKeyHeader(), 'Key:' );
+               $this->setMwGlobals( 'IP', $baseDir );
+               $conf = new HashConfig( [
+                       'ResourceBasePath' => $basePath,
+                       'UploadDirectory' => $uploadDir,
+                       'UploadPath' => $uploadPath,
+               ] );
+
+               // Some of these paths don't exist and will cause warnings
+               Wikimedia\suppressWarnings();
+               $actual = OutputPage::transformResourcePath( $conf, $path );
+               Wikimedia\restoreWarnings();
+
+               $this->assertEquals( $expected ?: $path, $actual );
        }
 
-       public function provideVaryHeaders() {
-               // note: getKeyHeader() automatically adds Vary: Cookie
+       public static function provideTransformFilePath() {
+               $baseDir = dirname( __DIR__ ) . '/data/media';
                return [
-                       [ // single header
-                               [
-                                       [ 'Cookie' ],
-                               ],
-                               'Vary: Cookie',
-                               'Key: Cookie',
+                       // File that matches basePath, and exists. Hash found and appended.
+                       [
+                               'baseDir' => $baseDir, 'basePath' => '/w',
+                               '/w/test.jpg',
+                               '/w/test.jpg?edcf2'
                        ],
-                       [ // non-unique headers
-                               [
-                                       [ 'Cookie' ],
-                                       [ 'Accept-Language' ],
-                                       [ 'Cookie' ],
-                               ],
-                               'Vary: Cookie, Accept-Language',
-                               'Key: Cookie,Accept-Language',
+                       // File that matches basePath, but not found on disk. Empty query.
+                       [
+                               'baseDir' => $baseDir, 'basePath' => '/w',
+                               '/w/unknown.png',
+                               '/w/unknown.png?'
                        ],
-                       [ // two headers with single options
-                               [
-                                       [ 'Cookie', [ 'param=phpsessid' ] ],
-                                       [ 'Accept-Language', [ 'substr=en' ] ],
-                               ],
-                               'Vary: Cookie, Accept-Language',
-                               'Key: Cookie;param=phpsessid,Accept-Language;substr=en',
+                       // File not matching basePath. Ignored.
+                       [
+                               'baseDir' => $baseDir, 'basePath' => '/w',
+                               '/files/test.jpg'
                        ],
-                       [ // one header with multiple options
-                               [
-                                       [ 'Cookie', [ 'param=phpsessid', 'param=userId' ] ],
-                               ],
-                               'Vary: Cookie',
-                               'Key: Cookie;param=phpsessid;param=userId',
+                       // Empty string. Ignored.
+                       [
+                               'baseDir' => $baseDir, 'basePath' => '/w',
+                               '',
+                               ''
                        ],
-                       [ // Duplicate option
-                               [
-                                       [ 'Cookie', [ 'param=phpsessid' ] ],
-                                       [ 'Cookie', [ 'param=phpsessid' ] ],
-                                       [ 'Accept-Language', [ 'substr=en', 'substr=en' ] ],
-                               ],
-                               'Vary: Cookie, Accept-Language',
-                               'Key: Cookie;param=phpsessid,Accept-Language;substr=en',
+                       // Similar path, but with domain component. Ignored.
+                       [
+                               'baseDir' => $baseDir, 'basePath' => '/w',
+                               '//example.org/w/test.jpg'
                        ],
-                       [ // Same header, different options
-                               [
-                                       [ 'Cookie', [ 'param=phpsessid' ] ],
-                                       [ 'Cookie', [ 'param=userId' ] ],
-                               ],
-                               'Vary: Cookie',
-                               'Key: Cookie;param=phpsessid;param=userId',
+                       [
+                               'baseDir' => $baseDir, 'basePath' => '/w',
+                               'https://example.org/w/test.jpg'
+                       ],
+                       // Unrelated path with domain component. Ignored.
+                       [
+                               'baseDir' => $baseDir, 'basePath' => '/w',
+                               'https://example.org/files/test.jpg'
+                       ],
+                       [
+                               'baseDir' => $baseDir, 'basePath' => '/w',
+                               '//example.org/files/test.jpg'
+                       ],
+                       // Unrelated path with domain, and empty base path (root mw install). Ignored.
+                       [
+                               'baseDir' => $baseDir, 'basePath' => '',
+                               'https://example.org/files/test.jpg'
+                       ],
+                       [
+                               'baseDir' => $baseDir, 'basePath' => '',
+                               // T155310
+                               '//example.org/files/test.jpg'
+                       ],
+                       // Check UploadPath before ResourceBasePath (T155146)
+                       [
+                               'baseDir' => dirname( $baseDir ), 'basePath' => '',
+                               'uploadDir' => $baseDir, 'uploadPath' => '/images',
+                               '/images/test.jpg',
+                               '/images/test.jpg?edcf2'
                        ],
                ];
        }
 
        /**
-        * @covers OutputPage::haveCacheVaryCookies
+        * Tests a particular case of transformCssMedia, using the given input, globals,
+        * expected return, and message
+        *
+        * Asserts that $expectedReturn is returned.
+        *
+        * options['printableQuery'] - value of query string for printable, or omitted for none
+        * options['handheldQuery'] - value of query string for handheld, or omitted for none
+        * options['media'] - passed into the method under the same name
+        * options['expectedReturn'] - expected return value
+        * options['message'] - PHPUnit message for assertion
+        *
+        * @param array $args Key-value array of arguments as shown above
         */
-       public function testHaveCacheVaryCookies() {
-               $request = new FauxRequest();
-               $context = new RequestContext();
-               $context->setRequest( $request );
-               $outputPage = new OutputPage( $context );
+       protected function assertTransformCssMediaCase( $args ) {
+               $queryData = [];
+               if ( isset( $args['printableQuery'] ) ) {
+                       $queryData['printable'] = $args['printableQuery'];
+               }
 
-               // No cookies are set.
-               $this->assertFalse( $outputPage->haveCacheVaryCookies() );
+               if ( isset( $args['handheldQuery'] ) ) {
+                       $queryData['handheld'] = $args['handheldQuery'];
+               }
 
-               // 'Token' is present but empty, so it shouldn't count.
-               $request->setCookie( 'Token', '' );
-               $this->assertFalse( $outputPage->haveCacheVaryCookies() );
+               $fauxRequest = new FauxRequest( $queryData, false );
+               $this->setMwGlobals( [
+                       'wgRequest' => $fauxRequest,
+               ] );
 
-               // 'Token' present and nonempty.
-               $request->setCookie( 'Token', '123' );
-               $this->assertTrue( $outputPage->haveCacheVaryCookies() );
+               $actualReturn = OutputPage::transformCssMedia( $args['media'] );
+               $this->assertSame( $args['expectedReturn'], $actualReturn, $args['message'] );
        }
 
        /**
-        * @covers OutputPage::addCategoryLinks
-        * @covers OutputPage::getCategories
+        * Tests print requests
+        *
+        * @covers OutputPage::transformCssMedia
         */
-       public function testGetCategories() {
-               $fakeResultWrapper = new FakeResultWrapper( [
-                       (object)[
-                               'pp_value' => 1,
-                               'page_title' => 'Test'
-                       ],
-                       (object)[
-                               'page_title' => 'Test2'
-                       ]
+       public function testPrintRequests() {
+               $this->assertTransformCssMediaCase( [
+                       'printableQuery' => '1',
+                       'media' => 'screen',
+                       'expectedReturn' => null,
+                       'message' => 'On printable request, screen returns null'
                ] );
-               $outputPage = $this->getMockBuilder( OutputPage::class )
-                       ->setConstructorArgs( [ new RequestContext() ] )
-                       ->setMethods( [ 'addCategoryLinksToLBAndGetResult' ] )
-                       ->getMock();
-               $outputPage->expects( $this->any() )
-                       ->method( 'addCategoryLinksToLBAndGetResult' )
-                       ->will( $this->returnValue( $fakeResultWrapper ) );
 
-               $outputPage->addCategoryLinks( [
-                       'Test' => 'Test',
-                       'Test2' => 'Test2',
+               $this->assertTransformCssMediaCase( [
+                       'printableQuery' => '1',
+                       'media' => self::SCREEN_MEDIA_QUERY,
+                       'expectedReturn' => null,
+                       'message' => 'On printable request, screen media query returns null'
+               ] );
+
+               $this->assertTransformCssMediaCase( [
+                       'printableQuery' => '1',
+                       'media' => self::SCREEN_ONLY_MEDIA_QUERY,
+                       'expectedReturn' => null,
+                       'message' => 'On printable request, screen media query with only returns null'
+               ] );
+
+               $this->assertTransformCssMediaCase( [
+                       'printableQuery' => '1',
+                       'media' => 'print',
+                       'expectedReturn' => '',
+                       'message' => 'On printable request, media print returns empty string'
                ] );
-               $this->assertEquals( [ 0 => 'Test', '1' => 'Test2' ], $outputPage->getCategories() );
-               $this->assertEquals( [ 0 => 'Test2' ], $outputPage->getCategories( 'normal' ) );
-               $this->assertEquals( [ 0 => 'Test' ], $outputPage->getCategories( 'hidden' ) );
        }
 
        /**
-        * @dataProvider provideLinkHeaders
-        * @covers OutputPage::addLinkHeader
-        * @covers OutputPage::getLinkHeader
+        * Tests screen requests, without either query parameter set
+        *
+        * @covers OutputPage::transformCssMedia
         */
-       public function testLinkHeaders( $headers, $result ) {
-               $outputPage = $this->newInstance();
+       public function testScreenRequests() {
+               $this->assertTransformCssMediaCase( [
+                       'media' => 'screen',
+                       'expectedReturn' => 'screen',
+                       'message' => 'On screen request, screen media type is preserved'
+               ] );
 
-               foreach ( $headers as $header ) {
-                       $outputPage->addLinkHeader( $header );
-               }
+               $this->assertTransformCssMediaCase( [
+                       'media' => 'handheld',
+                       'expectedReturn' => 'handheld',
+                       'message' => 'On screen request, handheld media type is preserved'
+               ] );
+
+               $this->assertTransformCssMediaCase( [
+                       'media' => self::SCREEN_MEDIA_QUERY,
+                       'expectedReturn' => self::SCREEN_MEDIA_QUERY,
+                       'message' => 'On screen request, screen media query is preserved.'
+               ] );
+
+               $this->assertTransformCssMediaCase( [
+                       'media' => self::SCREEN_ONLY_MEDIA_QUERY,
+                       'expectedReturn' => self::SCREEN_ONLY_MEDIA_QUERY,
+                       'message' => 'On screen request, screen media query with only is preserved.'
+               ] );
 
-               $this->assertEquals( $result, $outputPage->getLinkHeader() );
+               $this->assertTransformCssMediaCase( [
+                       'media' => 'print',
+                       'expectedReturn' => 'print',
+                       'message' => 'On screen request, print media type is preserved'
+               ] );
        }
 
-       public function provideLinkHeaders() {
-               return [
-                       [
-                               [],
-                               false
-                       ],
-                       [
-                               [ '<https://foo/bar.jpg>;rel=preload;as=image' ],
-                               'Link: <https://foo/bar.jpg>;rel=preload;as=image',
-                       ],
-                       [
-                               [ '<https://foo/bar.jpg>;rel=preload;as=image','<https://foo/baz.jpg>;rel=preload;as=image' ],
-                               'Link: <https://foo/bar.jpg>;rel=preload;as=image,<https://foo/baz.jpg>;rel=preload;as=image',
-                       ],
-               ];
+       /**
+        * Tests handheld behavior
+        *
+        * @covers OutputPage::transformCssMedia
+        */
+       public function testHandheld() {
+               $this->assertTransformCssMediaCase( [
+                       'handheldQuery' => '1',
+                       'media' => 'handheld',
+                       'expectedReturn' => '',
+                       'message' => 'On request with handheld querystring and media is handheld, returns empty string'
+               ] );
+
+               $this->assertTransformCssMediaCase( [
+                       'handheldQuery' => '1',
+                       'media' => 'screen',
+                       'expectedReturn' => null,
+                       'message' => 'On request with handheld querystring and media is screen, returns null'
+               ] );
        }
 
        /**
@@ -748,22 +1324,31 @@ class OutputPageTest extends MediaWikiTestCase {
        /**
         * @return OutputPage
         */
-       private function newInstance( $config = [] ) {
+       private function newInstance( $config = [], WebRequest $request = null ) {
                $context = new RequestContext();
 
-               $context->setConfig( new HashConfig( $config + [
-                       'AppleTouchIcon' => false,
-                       'DisableLangConversion' => true,
-                       'EnableCanonicalServerLink' => false,
-                       'Favicon' => false,
-                       'Feed' => false,
-                       'LanguageCode' => false,
-                       'ReferrerPolicy' => false,
-                       'RightsPage' => false,
-                       'RightsUrl' => false,
-                       'UniversalEditButton' => false,
+               $context->setConfig( new MultiConfig( [
+                       new HashConfig( $config + [
+                               'AppleTouchIcon' => false,
+                               'DisableLangConversion' => true,
+                               'EnableCanonicalServerLink' => false,
+                               'Favicon' => false,
+                               'Feed' => false,
+                               'LanguageCode' => false,
+                               'ReferrerPolicy' => false,
+                               'RightsPage' => false,
+                               'RightsUrl' => false,
+                               'UniversalEditButton' => false,
+                       ] ),
+                       $context->getConfig()
                ] ) );
 
+               $context->setTitle( Title::newFromText( 'My test page' ) );
+
+               if ( $request ) {
+                       $context->setRequest( $request );
+               }
+
                return new OutputPage( $context );
        }
 }