Set old_content_model & new_content_model for past changes

We might consider adding an in-process cache because there
will be a duplicate database lookup for content model and
wikitext of the same revision.

Bug: T230295
Change-Id: I9723f21069e03a49fa7131bd8f79c6e7e442104b

includes/VariableGenerator/RCVariableGenerator.php

@@ -212,19 +212,23 @@ class RCVariableGenerator extends VariableGenerator {
 		$this->addUserVars( $userIdentity, $this->rc )
 			->addTitleVars( $title, 'page', $this->rc );
 
-		// @todo Set old_content_model and new_content_model
 		$this->vars->setVar( 'action', 'edit' );
 		$this->vars->setVar( 'summary', $this->rc->getAttribute( 'rc_comment' ) );
 
 		$this->vars->setLazyLoadVar( 'new_wikitext', 'revision-text-by-id',
 			[ 'revid' => $this->rc->getAttribute( 'rc_this_oldid' ), 'contextUser' => $this->contextUser ] );
+		$this->vars->setLazyLoadVar( 'new_content_model', 'content-model-by-id',
+			[ 'revid' => $this->rc->getAttribute( 'rc_this_oldid' ) ] );
 
 		$parentId = $this->rc->getAttribute( 'rc_last_oldid' );
 		if ( $parentId ) {
 			$this->vars->setLazyLoadVar( 'old_wikitext', 'revision-text-by-id',
 				[ 'revid' => $parentId, 'contextUser' => $this->contextUser ] );
+			$this->vars->setLazyLoadVar( 'old_content_model', 'content-model-by-id',
+				[ 'revid' => $parentId ] );
 		} else {
 			$this->vars->setVar( 'old_wikitext', '' );
+			$this->vars->setVar( 'old_content_model', '' );
 		}
 
 		$this->addEditVars(

includes/VariableGenerator/RunVariableGenerator.php

@@ -284,7 +284,7 @@ class RunVariableGenerator extends VariableGenerator {
 
 		// We only have the upload comment and page text when using the UploadVerifyUpload hook
 		if ( $summary !== null && $text !== null ) {
-			// This block is adapted from self::getTextForFiltering()
+			// This block is adapted from self::getEditTextForFiltering()
 			$page = $this->wikiPageFactory->newFromTitle( $this->title );
 			if ( $this->title->exists() ) {
 				$revRec = $page->getRevisionRecord();

includes/Variables/LazyVariableComputer.php

@@ -11,7 +11,9 @@ use MediaWiki\Extension\AbuseFilter\TextExtractor;
 use MediaWiki\Permissions\PermissionManager;
 use MediaWiki\Permissions\RestrictionStore;
 use MediaWiki\Revision\RevisionLookup;
+use MediaWiki\Revision\RevisionRecord;
 use MediaWiki\Revision\RevisionStore;
+use MediaWiki\Revision\SlotRecord;
 use MediaWiki\User\UserEditTracker;
 use MediaWiki\User\UserGroupManager;
 use MediaWiki\User\UserIdentity;
@@ -375,6 +377,10 @@ class LazyVariableComputer {
 				$v2 = $getVarCB( $parameters['val2-var'] )->toInt();
 				$result = $v1 - $v2;
 				break;
+			case 'content-model-by-id':
+				$revRec = $this->revisionLookup->getRevisionById( $parameters['revid'] );
+				$result = $this->getContentModelFromRevision( $revRec );
+				break;
 			case 'revision-text-by-id':
 				$revRec = $this->revisionLookup->getRevisionById( $parameters['revid'] );
 				$result = $this->textExtractor->revisionToString( $revRec, $parameters['contextUser'] );
@@ -473,6 +479,20 @@ class LazyVariableComputer {
 		);
 	}
 
+	/**
+	 * @param ?RevisionRecord $revision
+	 * @return string
+	 */
+	private function getContentModelFromRevision( ?RevisionRecord $revision ): string {
+		// this is consistent with what is done on various places in RunVariableGenerator
+		// and RCVariableGenerator
+		if ( $revision !== null ) {
+			$content = $revision->getContent( SlotRecord::MAIN, RevisionRecord::RAW );
+			return $content->getModel();
+		}
+		return '';
+	}
+
 	/**
 	 * It's like WikiPage::prepareContentForEdit, but not for editing (old wikitext usually)
 	 *

includes/Variables/VariablesManager.php

@@ -169,6 +169,7 @@ class VariablesManager {
 			'user-age',
 			'user-block',
 			'revision-text-by-id',
+			'content-model-by-id',
 		];
 
 		/** @var LazyLoadedVariable[] $missingVars */

tests/phpunit/RCVariableGeneratorTest.php

@@ -65,6 +65,7 @@ class RCVariableGeneratorTest extends MediaWikiIntegrationTestCase {
 		switch ( $type ) {
 			case 'create':
 				$expectedValues['old_wikitext'] = '';
+				$expectedValues['old_content_model'] = '';
 			// Fallthrough
 			case 'edit':
 				$status = $this->editPage( $title, 'Some new text for testing RC vars.', $summary, NS_MAIN, $user );
@@ -245,9 +246,11 @@ class RCVariableGeneratorTest extends MediaWikiIntegrationTestCase {
 			'page_age' => 10,
 			'old_wikitext' => $oldText,
 			'old_size' => strlen( $oldText ),
+			'old_content_model' => 'wikitext',
 			'old_links' => [ $oldLink ],
 			'new_wikitext' => $newText,
 			'new_size' => strlen( $newText ),
+			'new_content_model' => 'wikitext',
 			'all_links' => [ $newLink ],
 			'timestamp' => (string)$timestamp,
 		];