ResourceLoaderULSModule::getModifiedTime updates continuously

Fix is simple: cache the hash of content per language

Added PHPUnit test for the same

Bug: 56856
Change-Id: I590b27af220d6e790c70728062d1a04c098b3d11

tests/phpunit/ResourceLoaderULSTest.php

@@ -0,0 +1,49 @@
+<?php
+/**
+ * PHP Unit tests for ResourceLoaderULSModule class.
+ *
+ * @file
+ * @ingroup Extensions
+ *
+ * @author Santhosh Thottingal
+ */
+
+/**
+ * @covers ResourceLoaderULSModule
+ */
+class ResourceLoaderULSModuleMemcachedTest extends MediaWikiTestCase {
+	/**
+	 * Test whether the modified time of the RL module varies
+	 * correctly with language code.
+	 * @covers ResourceLoaderSchemaModule::getModifiedTime
+	 */
+	function testModifiedTime() {
+		$request = new WebRequest();
+		$module = new ResourceLoaderULSModule();
+
+		$request->setVal( 'lang', 'he' );
+		$context = new ResourceLoaderContext(
+			new ResourceLoader(), $request );
+		$mtimeHebrew = $module->getModifiedTime( $context );
+		// sleep for 1 second
+		sleep( 1 );
+		$request->setVal( 'lang', 'hi' );
+		$context = new ResourceLoaderContext( new ResourceLoader(), $request );
+		$mtimeHindi = $module->getModifiedTime( $context );
+		$this->assertGreaterThan( $mtimeHebrew, $mtimeHindi, "Hindi has recent timestamp than Hebrew" );
+
+		// sleep for 1 second
+		sleep( 1 );
+		$request->setVal( 'lang', 'he' );
+		$context = new ResourceLoaderContext( new ResourceLoader(), $request );
+		$mtimeHebrewNew = $module->getModifiedTime( $context );
+		$this->assertEquals( $mtimeHebrewNew, $mtimeHebrew, "Hebrew timestamp remained same" );
+
+		// sleep for 1 second
+		sleep( 1 );
+		$request->setVal( 'lang', 'hi' );
+		$context = new ResourceLoaderContext( new ResourceLoader(), $request );
+		$mtimeHindiNew = $module->getModifiedTime( $context );
+		$this->assertEquals( $mtimeHindi, $mtimeHindiNew, "Hindi timestamp remained same" );
+	}
+}