diff --git a/repo/tests/phpunit/includes/Hooks/EditFilterHookRunnerTest.php b/repo/tests/phpunit/includes/Hooks/EditFilterHookRunnerTest.php
index 80b35548a43..84e90c85320 100644
--- a/repo/tests/phpunit/includes/Hooks/EditFilterHookRunnerTest.php
+++ b/repo/tests/phpunit/includes/Hooks/EditFilterHookRunnerTest.php
@@ -76,7 +76,7 @@ public function testRun_noHooksRegisteredGoodStatus() {
 		$this->assertStatusGood( $status );
 	}
 
-	public function runData() {
+	public static function runData() {
 		return [
 			'good existing item' => [
 				Status::newGood(),
diff --git a/repo/tests/phpunit/includes/Hooks/HtmlPageLinkRendererEndHookHandlerTest.php b/repo/tests/phpunit/includes/Hooks/HtmlPageLinkRendererEndHookHandlerTest.php
index d7d061c7791..e821d192754 100644
--- a/repo/tests/phpunit/includes/Hooks/HtmlPageLinkRendererEndHookHandlerTest.php
+++ b/repo/tests/phpunit/includes/Hooks/HtmlPageLinkRendererEndHookHandlerTest.php
@@ -70,9 +70,9 @@ public function testDoHtmlPageLinkRendererBegin_invalidContext( LinkRenderer $li
 		$this->assertEquals( [], $customAttribs );
 	}
 
-	public function overrideSpecialNewEntityLinkProvider(): iterable {
+	public static function overrideSpecialNewEntityLinkProvider(): iterable {
 		$entityContentFactory = WikibaseRepo::getEntityContentFactory();
-		$namespaceLookup = $this->getEntityNamespaceLookup();
+		$namespaceLookup = self::getEntityNamespaceLookup();
 
 		foreach ( $entityContentFactory->getEntityTypes() as $entityType ) {
 			$entityHandler = $entityContentFactory->getContentHandlerForType( $entityType );
@@ -113,8 +113,8 @@ public function testDoHtmlPageLinkRendererBegin_overrideSpecialNewEntityLink(
 		$this->assertStringContainsString( $specialPageTitle->getFullText(), $html );
 	}
 
-	public function noOverrideSpecialNewEntityLinkProvider(): iterable {
-		$lookup = $this->getEntityNamespaceLookup();
+	public static function noOverrideSpecialNewEntityLinkProvider(): iterable {
+		$lookup = self::getEntityNamespaceLookup();
 		$itemNs = $lookup->getEntityNamespace( 'item' );
 		$propertyNs = $lookup->getEntityNamespace( 'property' );
 		return [
diff --git a/repo/tests/phpunit/includes/Hooks/HtmlPageLinkRendererEndHookHandlerTestBase.php b/repo/tests/phpunit/includes/Hooks/HtmlPageLinkRendererEndHookHandlerTestBase.php
index 32d05703514..722b005c541 100644
--- a/repo/tests/phpunit/includes/Hooks/HtmlPageLinkRendererEndHookHandlerTestBase.php
+++ b/repo/tests/phpunit/includes/Hooks/HtmlPageLinkRendererEndHookHandlerTestBase.php
@@ -68,11 +68,11 @@ protected function newTitle( string $id, bool $exists = true, int $namespace = N
 		return $title;
 	}
 
-	protected function newContext( string $title = 'Special:Recentchanges' ): RequestContext {
+	protected static function newContext( string $title = 'Special:Recentchanges' ): RequestContext {
 		return RequestContext::newExtraneousContext( Title::newFromTextThrow( $title ) );
 	}
 
-	protected function getLinkRenderer(): LinkRenderer {
+	protected static function getLinkRenderer(): LinkRenderer {
 		$linkRenderer = MediaWikiServices::getInstance()
 			->getLinkRendererFactory()->create( [ 'renderForComment' => true ] );
 		return $linkRenderer;
@@ -219,7 +219,7 @@ private function getTermLookup() {
 		return $termLookup;
 	}
 
-	final protected function getEntityNamespaceLookup() {
+	final protected static function getEntityNamespaceLookup() {
 		$entityNamespaces = [
 			'item' => 0,
 			'property' => 122,
@@ -240,19 +240,19 @@ private function getInterwikiLookup() {
 		return $lookup;
 	}
 
-	public function validLinkRendererAndContextProvider() {
-		$commentLinkRenderer = $this->getLinkRenderer();
+	public static function validLinkRendererAndContextProvider() {
+		$commentLinkRenderer = self::getLinkRenderer();
 		$nonCommentLinkRenderer = MediaWikiServices::getInstance()->getLinkRenderer();
 
-		$specialPageContext = $this->newContext();
+		$specialPageContext = self::newContext();
 
-		$historyContext = $this->newContext( 'Foo' );
+		$historyContext = self::newContext( 'Foo' );
 		$historyContext->getRequest()->setVal( 'action', 'history' );
 
-		$diffContext = $this->newContext( 'Foo' );
+		$diffContext = self::newContext( 'Foo' );
 		$diffContext->getRequest()->setVal( 'diff', 123 );
 
-		$viewContext = $this->newContext( 'Foo' );
+		$viewContext = self::newContext( 'Foo' );
 
 		return [
 			'normal link, special page' => [ $nonCommentLinkRenderer, $specialPageContext ],
@@ -263,15 +263,15 @@ public function validLinkRendererAndContextProvider() {
 		];
 	}
 
-	public function invalidLinkRendererAndContextProvider() {
+	public static function invalidLinkRendererAndContextProvider() {
 		$linkRenderer = MediaWikiServices::getInstance()->getLinkRenderer();
 
-		$viewContext = $this->newContext( 'Foo' );
+		$viewContext = self::newContext( 'Foo' );
 
-		$diffContext = $this->newContext( 'Foo' );
+		$diffContext = self::newContext( 'Foo' );
 		$diffContext->getRequest()->setVal( 'diff', 123 );
 
-		$specialBadTitleContext = $this->newContext( 'Special:Badtitle' );
+		$specialBadTitleContext = self::newContext( 'Special:Badtitle' );
 
 		return [
 			'normal link, normal view' => [ $linkRenderer, $viewContext ],
diff --git a/repo/tests/phpunit/includes/Hooks/ShowSearchHitHandlerTest.php b/repo/tests/phpunit/includes/Hooks/ShowSearchHitHandlerTest.php
index 1d661080535..a1a6650b942 100644
--- a/repo/tests/phpunit/includes/Hooks/ShowSearchHitHandlerTest.php
+++ b/repo/tests/phpunit/includes/Hooks/ShowSearchHitHandlerTest.php
@@ -210,7 +210,7 @@ private function getEntityContentFactory() {
 		return $entityContentFactory;
 	}
 
-	public function getPlainSearches() {
+	public static function getPlainSearches() {
 		return [
 			"simple" => [
 				'Q1',
diff --git a/repo/tests/phpunit/includes/ParserOutput/EntityParserOutputGeneratorTestBase.php b/repo/tests/phpunit/includes/ParserOutput/EntityParserOutputGeneratorTestBase.php
index 60a3cb1cdc6..e22c6b793e1 100644
--- a/repo/tests/phpunit/includes/ParserOutput/EntityParserOutputGeneratorTestBase.php
+++ b/repo/tests/phpunit/includes/ParserOutput/EntityParserOutputGeneratorTestBase.php
@@ -67,7 +67,7 @@ protected function newLanguageFallbackChain() {
 		return $fallbackChain;
 	}
 
-	protected function newItem() {
+	protected static function newItem() {
 		$item = new Item( new ItemId( 'Q7799929' ) );
 
 		$item->setLabel( 'en', 'kitten item' );
diff --git a/repo/tests/phpunit/includes/ParserOutput/ExternalLinksDataUpdaterTest.php b/repo/tests/phpunit/includes/ParserOutput/ExternalLinksDataUpdaterTest.php
index 743c0328902..dd75c7e9ecb 100644
--- a/repo/tests/phpunit/includes/ParserOutput/ExternalLinksDataUpdaterTest.php
+++ b/repo/tests/phpunit/includes/ParserOutput/ExternalLinksDataUpdaterTest.php
@@ -38,7 +38,7 @@ private function newInstance() {
 	 * @param string $string
 	 * @param int $propertyId
 	 */
-	private function addStatement( StatementList $statements, $string, $propertyId = 1 ) {
+	private static function addStatement( StatementList $statements, $string, $propertyId = 1 ) {
 		$statements->addNewStatement(
 			new PropertyValueSnak( $propertyId, new StringValue( $string ) )
 		);
@@ -67,15 +67,15 @@ public function testUpdateParserOutput( StatementList $statements, array $expect
 		$this->assertSame( $expected, $actual );
 	}
 
-	public function externalLinksProvider() {
+	public static function externalLinksProvider() {
 		$set1 = new StatementList();
-		$this->addStatement( $set1, 'http://1.de' );
-		$this->addStatement( $set1, '' );
-		$this->addStatement( $set1, 'no url property', 2 );
+		self::addStatement( $set1, 'http://1.de' );
+		self::addStatement( $set1, '' );
+		self::addStatement( $set1, 'no url property', 2 );
 
 		$set2 = new StatementList();
-		$this->addStatement( $set2, 'http://2a.de' );
-		$this->addStatement( $set2, 'http://2b.de' );
+		self::addStatement( $set2, 'http://2a.de' );
+		self::addStatement( $set2, 'http://2b.de' );
 
 		return [
 			[ new StatementList(), [] ],
diff --git a/repo/tests/phpunit/includes/ParserOutput/FullEntityParserOutputGeneratorTest.php b/repo/tests/phpunit/includes/ParserOutput/FullEntityParserOutputGeneratorTest.php
index fe47741f109..941102ba02f 100644
--- a/repo/tests/phpunit/includes/ParserOutput/FullEntityParserOutputGeneratorTest.php
+++ b/repo/tests/phpunit/includes/ParserOutput/FullEntityParserOutputGeneratorTest.php
@@ -39,10 +39,10 @@ protected function setUp(): void {
 		$this->entityViewFactory = $this->mockEntityViewFactory( false );
 	}
 
-	public function provideTestGetParserOutput() {
+	public static function provideTestGetParserOutput() {
 		return [
 			[
-				$this->newItem(),
+				self::newItem(),
 				'kitten item',
 				[ 'http://an.url.com', 'https://another.url.org' ],
 				[ 'File:This_is_a_file.pdf', 'File:Selfie.jpg' ],
diff --git a/repo/tests/phpunit/includes/ParserOutput/GeoDataDataUpdaterTest.php b/repo/tests/phpunit/includes/ParserOutput/GeoDataDataUpdaterTest.php
index e23c6a2c371..e1389fb9787 100644
--- a/repo/tests/phpunit/includes/ParserOutput/GeoDataDataUpdaterTest.php
+++ b/repo/tests/phpunit/includes/ParserOutput/GeoDataDataUpdaterTest.php
@@ -34,7 +34,7 @@
  */
 class GeoDataDataUpdaterTest extends MediaWikiIntegrationTestCase {
 
-	private function willSkipTests() {
+	private static function willSkipTests() {
 		return !ExtensionRegistry::getInstance()->isLoaded( 'GeoData' );
 	}
 
@@ -63,13 +63,13 @@ public function testProcessStatement( array $expected, array $statements, $messa
 		$this->assertEquals( $expected, $updater->coordinates, $message );
 	}
 
-	public function processStatementProvider() {
-		if ( $this->willSkipTests() ) {
+	public static function processStatementProvider() {
+		if ( self::willSkipTests() ) {
 			return [ [ [], [], 'dummy test will be skipped' ] ];
 		}
 
-		$statements = $this->getStatements();
-		$coords = $this->getCoords();
+		$statements = self::getStatements();
+		$coords = self::getCoords();
 
 		return [
 			[
@@ -267,90 +267,90 @@ private function newGeoDataDataUpdater( array $preferredProperties ) {
 		);
 	}
 
-	private function getStatements() {
+	private static function getStatements() {
 		$statements = [];
 
-		$statements['P42-string'] = $this->newStatement(
+		$statements['P42-string'] = self::newStatement(
 			new NumericPropertyId( 'P42' ),
 			new StringValue( 'kittens!' )
 		);
 
-		$statements['P625-geo'] = $this->newStatement(
+		$statements['P625-geo'] = self::newStatement(
 			new NumericPropertyId( 'P625' ),
-			$this->newGlobeCoordinateValue( 19.7, 306.8, 'Q111' )
+			self::newGlobeCoordinateValue( 19.7, 306.8, 'Q111' )
 		);
 
-		$statements['P10-geo-A'] = $this->newStatement(
+		$statements['P10-geo-A'] = self::newStatement(
 			new NumericPropertyId( 'P10' ),
-			$this->newGlobeCoordinateValue( 40.748433, -73.985655 )
+			self::newGlobeCoordinateValue( 40.748433, -73.985655 )
 		);
 
-		$statements['P10-geo-B'] = $this->newStatement(
+		$statements['P10-geo-B'] = self::newStatement(
 			new NumericPropertyId( 'P10' ),
-			$this->newGlobeCoordinateValue( 44.264464, 52.643666 )
+			self::newGlobeCoordinateValue( 44.264464, 52.643666 )
 		);
 
-		$statements['P10-geo-preferred-A'] = $this->newStatementWithRank(
+		$statements['P10-geo-preferred-A'] = self::newStatementWithRank(
 			new NumericPropertyId( 'P10' ),
-			$this->newGlobeCoordinateValue( 50.02440, 41.50202 ),
+			self::newGlobeCoordinateValue( 50.02440, 41.50202 ),
 			Statement::RANK_PREFERRED
 		);
 
-		$statements['P10-geo-preferred-B'] = $this->newStatementWithRank(
+		$statements['P10-geo-preferred-B'] = self::newStatementWithRank(
 			new NumericPropertyId( 'P10' ),
-			$this->newGlobeCoordinateValue( 70.0144, 30.0015 ),
+			self::newGlobeCoordinateValue( 70.0144, 30.0015 ),
 			Statement::RANK_PREFERRED
 		);
 
-		$statements['P9000-geo-A'] = $this->newStatement(
+		$statements['P9000-geo-A'] = self::newStatement(
 			new NumericPropertyId( 'P9000' ),
-			$this->newGlobeCoordinateValue( 33.643664, 20.464222 )
+			self::newGlobeCoordinateValue( 33.643664, 20.464222 )
 		);
 
-		$statements['P9000-geo-B'] = $this->newStatementWithQualifier(
+		$statements['P9000-geo-B'] = self::newStatementWithQualifier(
 			new NumericPropertyId( 'P9000' ),
-			$this->newGlobeCoordinateValue( 11.1234, 12.5678 ),
+			self::newGlobeCoordinateValue( 11.1234, 12.5678 ),
 			new SnakList( [
 				new PropertyValueSnak(
 					new NumericPropertyId( 'P625' ),
-					$this->newGlobeCoordinateValue( 30.0987, 20.1234 )
+					self::newGlobeCoordinateValue( 30.0987, 20.1234 )
 				),
 			] )
 		);
 
-		$statements['P9000-geo-preferred'] = $this->newStatementWithRank(
+		$statements['P9000-geo-preferred'] = self::newStatementWithRank(
 			new NumericPropertyId( 'P9000' ),
-			$this->newGlobeCoordinateValue( 77.7777, 33.3333 ),
+			self::newGlobeCoordinateValue( 77.7777, 33.3333 ),
 			Statement::RANK_PREFERRED
 		);
 
-		$statements['P17-geo-deprecated'] = $this->newStatementWithRank(
+		$statements['P17-geo-deprecated'] = self::newStatementWithRank(
 			new NumericPropertyId( 'P17' ),
-			$this->newGlobeCoordinateValue( 10.0234, 11.52352 ),
+			self::newGlobeCoordinateValue( 10.0234, 11.52352 ),
 			Statement::RANK_DEPRECATED
 		);
 
-		$statements['P20-some-value'] = $this->newStatement( new NumericPropertyId( 'P20' ) );
+		$statements['P20-some-value'] = self::newStatement( new NumericPropertyId( 'P20' ) );
 
-		$statements['P10-mismatch'] = $this->newStatement(
+		$statements['P10-mismatch'] = self::newStatement(
 			new NumericPropertyId( 'P10' ),
 			new StringValue( 'omg! wrong value type' )
 		);
 
-		$statements['P404-unknown-property'] = $this->newStatement(
+		$statements['P404-unknown-property'] = self::newStatement(
 			new NumericPropertyId( 'P404' ),
-			$this->newGlobeCoordinateValue( 40.733643, -72.352153 )
+			self::newGlobeCoordinateValue( 40.733643, -72.352153 )
 		);
 
-		$statements['P9002-unknown-globe'] = $this->newStatement(
+		$statements['P9002-unknown-globe'] = self::newStatement(
 			new NumericPropertyId( 'P9002' ),
-			$this->newGlobeCoordinateValue( 9.017, 14.0987, 'Q147' )
+			self::newGlobeCoordinateValue( 9.017, 14.0987, 'Q147' )
 		);
 
 		return $statements;
 	}
 
-	private function getCoords() {
+	private static function getCoords() {
 		return [
 			'P625-geo' => new Coord( 19.7, 306.8, 'mars' ),
 			'P10-geo-A' => new Coord( 40.748433, -73.985655 ),
@@ -363,7 +363,7 @@ private function getCoords() {
 		];
 	}
 
-	private function newStatement( NumericPropertyId $propertyId, DataValue $dataValue = null ) {
+	private static function newStatement( NumericPropertyId $propertyId, DataValue $dataValue = null ) {
 		$guidGenerator = new GuidGenerator();
 
 		if ( $dataValue === null ) {
@@ -377,29 +377,29 @@ private function newStatement( NumericPropertyId $propertyId, DataValue $dataVal
 		return new Statement( $snak, null, null, $guid );
 	}
 
-	private function newStatementWithRank(
+	private static function newStatementWithRank(
 		NumericPropertyId $propertyId,
 		DataValue $dataValue,
 		$rank
 	 ) {
-		$rankedStatement = $this->newStatement( $propertyId, $dataValue );
+		$rankedStatement = self::newStatement( $propertyId, $dataValue );
 		$rankedStatement->setRank( $rank );
 
 		return $rankedStatement;
 	}
 
-	private function newStatementWithQualifier(
+	private static function newStatementWithQualifier(
 		NumericPropertyId $propertyId,
 		DataValue $dataValue,
 		SnakList $qualifiers
 	) {
-		$statement = $this->newStatement( $propertyId, $dataValue );
+		$statement = self::newStatement( $propertyId, $dataValue );
 		$statement->setQualifiers( $qualifiers );
 
 		return $statement;
 	}
 
-	private function newGlobeCoordinateValue( $lat, $lon, $globeId = 'Q2' ) {
+	private static function newGlobeCoordinateValue( $lat, $lon, $globeId = 'Q2' ) {
 		$latLongValue = new LatLongValue( $lat, $lon );
 
 		// default globe is 'Q2' (earth)
diff --git a/repo/tests/phpunit/includes/ParserOutput/ImageLinksDataUpdaterTest.php b/repo/tests/phpunit/includes/ParserOutput/ImageLinksDataUpdaterTest.php
index 5035187838e..8c4cff1b2e7 100644
--- a/repo/tests/phpunit/includes/ParserOutput/ImageLinksDataUpdaterTest.php
+++ b/repo/tests/phpunit/includes/ParserOutput/ImageLinksDataUpdaterTest.php
@@ -55,7 +55,7 @@ private function newInstance() {
 	 * @param string $string
 	 * @param int $propertyId
 	 */
-	private function addStatement( StatementList $statements, $string, $propertyId = 1 ) {
+	private static function addStatement( StatementList $statements, $string, $propertyId = 1 ) {
 		$statements->addNewStatement(
 			new PropertyValueSnak( $propertyId, new StringValue( $string ) )
 		);
@@ -81,19 +81,19 @@ public function testUpdateParserOutput(
 		$this->assertSame( $expectedFileSearchOptions, $parserOutput->getFileSearchOptions() );
 	}
 
-	public function imageLinksProvider() {
+	public static function imageLinksProvider() {
 		$set1 = new StatementList();
-		$this->addStatement( $set1, '1.jpg' );
-		$this->addStatement( $set1, '' );
-		$this->addStatement( $set1, 'no image property', 2 );
+		self::addStatement( $set1, '1.jpg' );
+		self::addStatement( $set1, '' );
+		self::addStatement( $set1, 'no image property', 2 );
 
 		$set2 = new StatementList();
-		$this->addStatement( $set2, '2a.jpg' );
-		$this->addStatement( $set2, '2b.jpg' );
+		self::addStatement( $set2, '2a.jpg' );
+		self::addStatement( $set2, '2b.jpg' );
 
 		$set3 = new StatementList();
-		$this->addStatement( $set3, '2a.jpg' );
-		$this->addStatement( $set3, 'Exists.png' );
+		self::addStatement( $set3, '2a.jpg' );
+		self::addStatement( $set3, 'Exists.png' );
 
 		return [
 			[ new StatementList(), [], [] ],
diff --git a/repo/tests/phpunit/includes/ParserOutput/PageImagesDataUpdaterTest.php b/repo/tests/phpunit/includes/ParserOutput/PageImagesDataUpdaterTest.php
index 809585a988f..b4f000e398a 100644
--- a/repo/tests/phpunit/includes/ParserOutput/PageImagesDataUpdaterTest.php
+++ b/repo/tests/phpunit/includes/ParserOutput/PageImagesDataUpdaterTest.php
@@ -37,7 +37,7 @@ private function newInstance( array $propertyIds ) {
 	 * @param string $string
 	 * @param int $rank
 	 */
-	private function addStatement(
+	private static function addStatement(
 		StatementList $statements,
 		$propertyId,
 		$string,
@@ -95,30 +95,30 @@ public function testUpdateParserOutput(
 		$instance->updateParserOutput( $parserOutput );
 	}
 
-	public function bestImageProvider() {
+	public static function bestImageProvider() {
 		$statements = new StatementList();
 
-		$this->addStatement( $statements, 1, '1.jpg' );
+		self::addStatement( $statements, 1, '1.jpg' );
 
 		$statements->addNewStatement( new PropertyNoValueSnak( 2 ) );
 		$statements->addNewStatement( new PropertySomeValueSnak( 2 ) );
 		$statements->addNewStatement( new PropertyValueSnak( 2, new BooleanValue( true ) ) );
-		$this->addStatement( $statements, 2, '' );
-		$this->addStatement( $statements, 2, '2.jpg', Statement::RANK_DEPRECATED );
+		self::addStatement( $statements, 2, '' );
+		self::addStatement( $statements, 2, '2.jpg', Statement::RANK_DEPRECATED );
 
 		$statements->addNewStatement( new PropertySomeValueSnak( 3 ) );
-		$this->addStatement( $statements, 3, '3a.jpg' );
-		$this->addStatement( $statements, 3, '3b.jpg' );
-
-		$this->addStatement( $statements, 4, 'Four 1.jpg', Statement::RANK_DEPRECATED );
-		$this->addStatement( $statements, 4, 'Four 2.jpg' );
-		$this->addStatement( $statements, 4, 'Four 3.jpg' );
-
-		$this->addStatement( $statements, 5, '5a.jpg' );
-		$this->addStatement( $statements, 4, '5b.jpg', Statement::RANK_DEPRECATED );
-		$this->addStatement( $statements, 5, '5c.jpg', Statement::RANK_PREFERRED );
-		$this->addStatement( $statements, 5, '5d.jpg' );
-		$this->addStatement( $statements, 5, '5e.jpg', Statement::RANK_PREFERRED );
+		self::addStatement( $statements, 3, '3a.jpg' );
+		self::addStatement( $statements, 3, '3b.jpg' );
+
+		self::addStatement( $statements, 4, 'Four 1.jpg', Statement::RANK_DEPRECATED );
+		self::addStatement( $statements, 4, 'Four 2.jpg' );
+		self::addStatement( $statements, 4, 'Four 3.jpg' );
+
+		self::addStatement( $statements, 5, '5a.jpg' );
+		self::addStatement( $statements, 4, '5b.jpg', Statement::RANK_DEPRECATED );
+		self::addStatement( $statements, 5, '5c.jpg', Statement::RANK_PREFERRED );
+		self::addStatement( $statements, 5, '5d.jpg' );
+		self::addStatement( $statements, 5, '5e.jpg', Statement::RANK_PREFERRED );
 
 		return [
 			// Find nothing for various reasons.
diff --git a/repo/tests/phpunit/includes/Parsers/MwDateFormatParserFactoryTest.php b/repo/tests/phpunit/includes/Parsers/MwDateFormatParserFactoryTest.php
index f72b17fd568..0c48bb9b66c 100644
--- a/repo/tests/phpunit/includes/Parsers/MwDateFormatParserFactoryTest.php
+++ b/repo/tests/phpunit/includes/Parsers/MwDateFormatParserFactoryTest.php
@@ -79,7 +79,7 @@ public function testParseWithValidInputs(
 			"'$input' in $languageCode became $parsed instead of $expected" );
 	}
 
-	public function validInputProvider() {
+	public static function validInputProvider() {
 		$dateFormatPreferences = [
 			'mdy' => TimeValue::PRECISION_MINUTE,
 			'dmy' => TimeValue::PRECISION_MINUTE,
@@ -93,12 +93,12 @@ public function validInputProvider() {
 		];
 
 		$languageFactory = MediaWikiServices::getInstance()->getLanguageFactory();
-		foreach ( $this->getLanguageCodes() as $languageCode ) {
+		foreach ( self::getLanguageCodes() as $languageCode ) {
 			$language = $languageFactory->getLanguage( $languageCode );
 
 			foreach ( $dateFormatPreferences as $dateFormatPreference => $maximumPrecision ) {
 				foreach ( $dateFormatTypes as $dateFormatType => $precision ) {
-					$mwTimestamp = $this->generateMwTimestamp();
+					$mwTimestamp = self::generateMwTimestamp();
 
 					$dateFormat = $language->getDateFormatString( $dateFormatType, $dateFormatPreference );
 					$input = $language->sprintfDate( $dateFormat, $mwTimestamp );
@@ -110,7 +110,7 @@ public function validInputProvider() {
 						? TimeValue::CALENDAR_JULIAN
 						: TimeValue::CALENDAR_GREGORIAN;
 					$expected = new TimeValue(
-						$this->getIsoTimestamp( $mwTimestamp, $precision ),
+						self::getIsoTimestamp( $mwTimestamp, $precision ),
 						0, 0, 0,
 						$precision,
 						$calendarModel
@@ -128,7 +128,7 @@ public function validInputProvider() {
 		}
 	}
 
-	private function getLanguageCodes() {
+	private static function getLanguageCodes() {
 		// Focus on a critical subset of languages. Enable the following MediaWiki dependency to
 		// test the full set of all 400+ supported languages. This may take several minutes.
 		// return array_keys( MediaWikiServices::getInstance()->getLanguageNameUtils()->getLanguageNames() );
@@ -160,7 +160,7 @@ private function getLanguageCodes() {
 	/**
 	 * @return string
 	 */
-	private function generateMwTimestamp() {
+	private static function generateMwTimestamp() {
 		static $mwTimestamps;
 
 		if ( $mwTimestamps === null ) {
@@ -190,7 +190,7 @@ private function generateMwTimestamp() {
 	 *
 	 * @return string
 	 */
-	private function getIsoTimestamp( $mwTimestamp, $precision ) {
+	private static function getIsoTimestamp( $mwTimestamp, $precision ) {
 		if ( $precision <= TimeValue::PRECISION_YEAR ) {
 			$mwTimestamp = substr( $mwTimestamp, 0, 4 ) . '0000000000';
 		} elseif ( $precision === TimeValue::PRECISION_MONTH ) {
diff --git a/repo/tests/phpunit/includes/Parsers/TimeFormatterParserRoundtripTest.php b/repo/tests/phpunit/includes/Parsers/TimeFormatterParserRoundtripTest.php
index a005d90015f..78bab18f780 100644
--- a/repo/tests/phpunit/includes/Parsers/TimeFormatterParserRoundtripTest.php
+++ b/repo/tests/phpunit/includes/Parsers/TimeFormatterParserRoundtripTest.php
@@ -62,10 +62,10 @@ public static function isoTimestampProvider() {
 		];
 	}
 
-	public function timeValueProvider() {
+	public static function timeValueProvider() {
 		$gregorian = 'http://www.wikidata.org/entity/Q1985727';
 
-		foreach ( $this->isoTimestampProvider() as $case ) {
+		foreach ( self::isoTimestampProvider() as $case ) {
 			yield [ new TimeValue( $case[0], 0, 0, 0, $case[1], $gregorian ) ];
 		}
 	}
diff --git a/repo/tests/phpunit/includes/Rdf/DateTimeValueCleanerTest.php b/repo/tests/phpunit/includes/Rdf/DateTimeValueCleanerTest.php
index 79323d4e768..7879078244c 100644
--- a/repo/tests/phpunit/includes/Rdf/DateTimeValueCleanerTest.php
+++ b/repo/tests/phpunit/includes/Rdf/DateTimeValueCleanerTest.php
@@ -41,7 +41,7 @@ public static function illegalTimeValueProvider() {
 		];
 	}
 
-	public function getDates() {
+	public static function getDates() {
 		$greg = TimeValue::CALENDAR_GREGORIAN;
 		$jul = TimeValue::CALENDAR_JULIAN;
 		$year1m = TimeValue::PRECISION_YEAR1M;
@@ -93,7 +93,7 @@ public function getDates() {
 		];
 	}
 
-	public function getDatesXSD11() {
+	public static function getDatesXSD11() {
 		$greg = TimeValue::CALENDAR_GREGORIAN;
 		$jul = TimeValue::CALENDAR_JULIAN;
 		$year10 = TimeValue::PRECISION_YEAR10;
diff --git a/repo/tests/phpunit/includes/Rdf/FullStatementRdfBuilderTest.php b/repo/tests/phpunit/includes/Rdf/FullStatementRdfBuilderTest.php
index 3112bd305f0..34c30d7adbf 100644
--- a/repo/tests/phpunit/includes/Rdf/FullStatementRdfBuilderTest.php
+++ b/repo/tests/phpunit/includes/Rdf/FullStatementRdfBuilderTest.php
@@ -122,7 +122,7 @@ private function assertTriples( $dataSetNames, RdfWriter $writer ) {
 		$this->helper->assertNTriplesEqualsDataset( $dataSetNames, $actual );
 	}
 
-	public function provideAddEntity() {
+	public static function provideAddEntity() {
 		$props = array_map(
 			function ( $data ) {
 				/** @var PropertyId $propertyId */
@@ -172,7 +172,7 @@ public function testAddEntity( $entityName, $flavor, $dataSetNames, array $expec
 		$this->assertEquals( $expectedMentions, array_keys( $mentioned ), 'Entities mentioned' );
 	}
 
-	public function provideAddEntityTestCasesWhenPropertiesFromOtherWikibase() {
+	public static function provideAddEntityTestCasesWhenPropertiesFromOtherWikibase() {
 		$props = array_map(
 			function ( $data ) {
 				/** @var PropertyId $propertyId */
diff --git a/repo/tests/phpunit/includes/Rdf/PropertyRdfBuilderTest.php b/repo/tests/phpunit/includes/Rdf/PropertyRdfBuilderTest.php
index b78a6d18c86..98d35a4d3ba 100644
--- a/repo/tests/phpunit/includes/Rdf/PropertyRdfBuilderTest.php
+++ b/repo/tests/phpunit/includes/Rdf/PropertyRdfBuilderTest.php
@@ -73,12 +73,12 @@ public function testInternalRdfBuildersCallsAddEntity_dependingOnFlavorFlags(
 		$builder->addEntity( $property );
 	}
 
-	public function provideAddEntity(): array {
+	public static function provideAddEntity(): array {
 		return [
-			"No flavors selected" => [ 0, $this->getTestProperty() ],
-			"Just truthy statements requested" => [ RdfProducer::PRODUCE_TRUTHY_STATEMENTS, $this->getTestProperty(), true ],
-			"Full statements requested" => [ RdfProducer::PRODUCE_ALL_STATEMENTS, $this->getTestProperty(), false, true ],
-			"All statements requested" => [ RdfProducer::PRODUCE_ALL, $this->getTestProperty(), true, true ],
+			"No flavors selected" => [ 0, self::getTestProperty() ],
+			"Just truthy statements requested" => [ RdfProducer::PRODUCE_TRUTHY_STATEMENTS, self::getTestProperty(), true ],
+			"Full statements requested" => [ RdfProducer::PRODUCE_ALL_STATEMENTS, self::getTestProperty(), false, true ],
+			"All statements requested" => [ RdfProducer::PRODUCE_ALL, self::getTestProperty(), true, true ],
 		];
 	}
 
@@ -92,7 +92,7 @@ private function getBuilder( $flavorFlags ): PropertyRdfBuilder {
 		);
 	}
 
-	private function getTestProperty(): Property {
+	private static function getTestProperty(): Property {
 		return new Property( null,
 			null,
 			'footype' );
diff --git a/repo/tests/phpunit/includes/Rdf/RdfBuilderTest.php b/repo/tests/phpunit/includes/Rdf/RdfBuilderTest.php
index bd38a54e57c..521e642b5c1 100644
--- a/repo/tests/phpunit/includes/Rdf/RdfBuilderTest.php
+++ b/repo/tests/phpunit/includes/Rdf/RdfBuilderTest.php
@@ -461,7 +461,7 @@ public function testAddEntityRedirect(): void {
 		$this->helper->assertNTriplesEquals( $expected, $builder->getRDF() );
 	}
 
-	public function getProduceOptions(): iterable {
+	public static function getProduceOptions(): iterable {
 		return [
 			[
 				'Q4',
@@ -586,7 +586,7 @@ public function testDeduplication_whenPropertiesFromOtherWikibase(): void {
 		$this->helper->assertNTriplesEqualsDataset( 'Q7_Q9_dedup_foreignsource_properties', $data1 . $data2 );
 	}
 
-	public function getProps(): iterable {
+	public static function getProps(): iterable {
 		return [
 			'simple prop' => [
 				'prop1',
diff --git a/repo/tests/phpunit/includes/Rdf/ValueSnakRdfBuilderFactoryTest.php b/repo/tests/phpunit/includes/Rdf/ValueSnakRdfBuilderFactoryTest.php
index 050466dd854..5bf24357197 100644
--- a/repo/tests/phpunit/includes/Rdf/ValueSnakRdfBuilderFactoryTest.php
+++ b/repo/tests/phpunit/includes/Rdf/ValueSnakRdfBuilderFactoryTest.php
@@ -27,7 +27,7 @@
  */
 class ValueSnakRdfBuilderFactoryTest extends \PHPUnit\Framework\TestCase {
 
-	public function getBuilderFlags() {
+	public static function getBuilderFlags() {
 		return [
 			[ 0 ], // simple values
 			[ RdfProducer::PRODUCE_FULL_VALUES ], // complex values