ResourceLoader: Remove unused 'dir' parameter to load.php

When MediaWiki creates load.php URLs, in OutputPage and via RL\Client,
it sets 'lang', not 'dir'. The direction is automatically derived
from the language, which makes the library easier to use for developers,
and also avoids a potentially confusing scenario in which the two
are different (e.g. lang=he and dir=ltr would not make sense, and
would further risk poisoning LTR content in an RTL/Hebrew-related
cache somewhere).

Bug: T225845
Change-Id: I14905c85bb5e3bb47a681dc99668b92844d22f04

4 files changed, 13 insertions, 36 deletions

diff --git a/includes/ResourceLoader/Context.php b/includes/ResourceLoader/Context.php
index 3ee03704a36c..c2c52602c98e 100644
--- a/includes/ResourceLoader/Context.php
+++ b/includes/ResourceLoader/Context.php
@@ -220,14 +220,9 @@ class Context implements MessageLocalizer {
 
 	public function getDirection(): string {
 		if ( $this->direction === null ) {
-			$direction = $this->getRequest()->getRawVal( 'dir' );
-			if ( $direction === 'ltr' || $direction === 'rtl' ) {
-				$this->direction = $direction;
-			} else {
-				// Determine directionality based on user language (T8100)
-				$this->direction = MediaWikiServices::getInstance()->getLanguageFactory()
-					->getLanguage( $this->getLanguage() )->getDir();
-			}
+			// Determine directionality based on user language (T8100)
+			$this->direction = MediaWikiServices::getInstance()->getLanguageFactory()
+				->getLanguage( $this->getLanguage() )->getDir();
 		}
 		return $this->direction;
 	}
diff --git a/tests/phpunit/ResourceLoaderTestCase.php b/tests/phpunit/ResourceLoaderTestCase.php
index e12d0b2cc3f2..2de39a8a42d8 100644
--- a/tests/phpunit/ResourceLoaderTestCase.php
+++ b/tests/phpunit/ResourceLoaderTestCase.php
@@ -25,7 +25,6 @@ abstract class ResourceLoaderTestCase extends MediaWikiIntegrationTestCase {
 	/**
 	 * @param array|string $options Language code or options array
 	 * - string 'lang' Language code
-	 * - string 'dir' Language direction (ltr or rtl)
 	 * - string 'modules' Pipe-separated list of module names
 	 * - string|null 'only' "scripts" (unwrapped script), "styles" (stylesheet), or null
 	 *    (mw.loader.implement).
@@ -34,13 +33,11 @@ abstract class ResourceLoaderTestCase extends MediaWikiIntegrationTestCase {
 	 */
 	protected function getResourceLoaderContext( $options = [], ?ResourceLoader $rl = null ) {
 		if ( is_string( $options ) ) {
-			// Back-compat for extension tests
 			$options = [ 'lang' => $options ];
 		}
 		$options += [
 			'debug' => 'true',
 			'lang' => 'en',
-			'dir' => 'ltr',
 			'skin' => 'fallback',
 			'modules' => 'startup',
 			'only' => 'scripts',
@@ -65,12 +62,7 @@ abstract class ResourceLoaderTestCase extends MediaWikiIntegrationTestCase {
 			'sourcemap' => $options['sourcemap'],
 			'target' => 'phpunit',
 		] );
-		$ctx = $this->getMockBuilder( Context::class )
-			->setConstructorArgs( [ $resourceLoader, $request ] )
-			->onlyMethods( [ 'getDirection' ] )
-			->getMock();
-		$ctx->method( 'getDirection' )->willReturn( $options['dir'] );
-		return $ctx;
+		return new Context( $resourceLoader, $request );
 	}
 
 	public static function getSettings() {
diff --git a/tests/phpunit/includes/ResourceLoader/ContextTest.php b/tests/phpunit/includes/ResourceLoader/ContextTest.php
index c570f7addfa4..cf127b1d538a 100644
--- a/tests/phpunit/includes/ResourceLoader/ContextTest.php
+++ b/tests/phpunit/includes/ResourceLoader/ContextTest.php
@@ -104,18 +104,14 @@ class ContextTest extends TestCase {
 			[ 'lang' => 'he' ],
 			'rtl',
 		];
-		yield 'explicit LTR' => [
-			[ 'lang' => 'he', 'dir' => 'ltr' ],
-			'ltr',
-		];
-		yield 'explicit RTL' => [
-			[ 'lang' => 'en', 'dir' => 'rtl' ],
+		yield 'RTL variant of LTR language' => [
+			[ 'lang' => 'en-rtl' ],
 			'rtl',
 		];
 		// Not supported, but tested to cover the case and detect change
-		yield 'invalid dir' => [
-			[ 'lang' => 'he', 'dir' => 'xyz' ],
-			'rtl',
+		yield 'invalid language' => [
+			[ 'lang' => 'invalid-xyz' ],
+			'ltr',
 		];
 	}
 
diff --git a/tests/phpunit/includes/ResourceLoader/FileModuleTest.php b/tests/phpunit/includes/ResourceLoader/FileModuleTest.php
index a0ea3374a1d9..0bc83008d3ba 100644
--- a/tests/phpunit/includes/ResourceLoader/FileModuleTest.php
+++ b/tests/phpunit/includes/ResourceLoader/FileModuleTest.php
@@ -283,14 +283,8 @@ class FileModuleTest extends ResourceLoaderTestCase {
 		] );
 		$expectedModule->setName( 'testing' );
 
-		$contextLtr = $this->getResourceLoaderContext( [
-			'lang' => 'en',
-			'dir' => 'ltr',
-		] );
-		$contextRtl = $this->getResourceLoaderContext( [
-			'lang' => 'he',
-			'dir' => 'rtl',
-		] );
+		$contextLtr = $this->getResourceLoaderContext( [ 'lang' => 'en' ] );
+		$contextRtl = $this->getResourceLoaderContext( [ 'lang' => 'he' ] );
 
 		// Since we want to compare the effect of @noflip+@embed against the effect of just @embed, and
 		// the @noflip annotations are always preserved, we need to strip them first.
@@ -313,13 +307,13 @@ class FileModuleTest extends ResourceLoaderTestCase {
 		] );
 		$plain->setName( 'test' );
 
-		$context = $this->getResourceLoaderContext( [ 'lang' => 'en', 'dir' => 'ltr' ] );
+		$context = $this->getResourceLoaderContext( [ 'lang' => 'en' ] );
 		$this->assertEquals(
 			[ 'all' => ".example { text-align: left; }\n" ],
 			$plain->getStyles( $context ),
 			'Unchanged styles in LTR mode'
 		);
-		$context = $this->getResourceLoaderContext( [ 'lang' => 'he', 'dir' => 'rtl' ] );
+		$context = $this->getResourceLoaderContext( [ 'lang' => 'he' ] );
 		$this->assertEquals(
 			[ 'all' => ".example { text-align: right; }\n" ],
 			$plain->getStyles( $context ),