diff --git a/ApiCategoryTree.php b/ApiCategoryTree.php
index 4a417cfc..3be6dc91 100644
--- a/ApiCategoryTree.php
+++ b/ApiCategoryTree.php
@@ -3,7 +3,7 @@
 class ApiCategoryTree extends ApiBase {
 	public function execute() {
 		$params = $this->extractRequestParams();
-		$options = array();
+		$options = [];
 		if ( isset( $params['options'] ) ) {
 			$options = FormatJson::decode( $params['options'] );
 			if ( !is_object( $options ) ) {
@@ -46,10 +46,10 @@ class ApiCategoryTree extends ApiBase {
 			$params = $this->extractRequestParams();
 			$title = CategoryTree::makeTitle( $params['category'] );
 			return wfGetDB( DB_SLAVE )->selectField( 'page', 'page_touched',
-				array(
+				[
 					'page_namespace' => NS_CATEGORY,
 					'page_title' => $title->getDBkey(),
-				),
+				],
 				__METHOD__
 			);
 		}
@@ -89,10 +89,10 @@ class ApiCategoryTree extends ApiBase {
 
 			$wgMemc->set(
 				$mckey,
-				array(
+				[
 					'timestamp' => wfTimestampNow(),
 					'value' => $html
-				),
+				],
 				86400
 			);
 		}
@@ -100,15 +100,15 @@ class ApiCategoryTree extends ApiBase {
 	}
 
 	public function getAllowedParams() {
-		return array(
-			'category' => array(
+		return [
+			'category' => [
 				ApiBase::PARAM_TYPE => 'string',
 				ApiBase::PARAM_REQUIRED => true,
-			),
-			'options' => array(
+			],
+			'options' => [
 				ApiBase::PARAM_TYPE => 'string',
-			),
-		);
+			],
+		];
 	}
 
 	public function isInternal() {
diff --git a/CategoryPageSubclass.php b/CategoryPageSubclass.php
index a37c6022..f71f2617 100644
--- a/CategoryPageSubclass.php
+++ b/CategoryPageSubclass.php
@@ -53,7 +53,7 @@ class CategoryTreeCategoryViewer extends CategoryViewer {
 	}
 
 	function clearCategoryState() {
-		$this->child_cats = array();
+		$this->child_cats = [];
 		parent::clearCategoryState();
 	}
 
diff --git a/CategoryTree.alias.php b/CategoryTree.alias.php
index e92d626f..043be2aa 100644
--- a/CategoryTree.alias.php
+++ b/CategoryTree.alias.php
@@ -10,494 +10,494 @@
  */
 // @codingStandardsIgnoreFile
 
-$specialPageAliases = array();
+$specialPageAliases = [];
 
 /** English (English) */
-$specialPageAliases['en'] = array(
-	'CategoryTree' => array( 'CategoryTree' ),
-);
+$specialPageAliases['en'] = [
+	'CategoryTree' => [ 'CategoryTree' ],
+];
 
 /** Afrikaans (Afrikaans) */
-$specialPageAliases['af'] = array(
-	'CategoryTree' => array( 'KategorieBoom' ),
-);
+$specialPageAliases['af'] = [
+	'CategoryTree' => [ 'KategorieBoom' ],
+];
 
 /** Aragonese (aragonés) */
-$specialPageAliases['an'] = array(
-	'CategoryTree' => array( 'Árbol_de_categorías' ),
-);
+$specialPageAliases['an'] = [
+	'CategoryTree' => [ 'Árbol_de_categorías' ],
+];
 
 /** Arabic (العربية) */
-$specialPageAliases['ar'] = array(
-	'CategoryTree' => array( 'شجرة_تصنيف' ),
-);
+$specialPageAliases['ar'] = [
+	'CategoryTree' => [ 'شجرة_تصنيف' ],
+];
 
 /** Aramaic (ܐܪܡܝܐ) */
-$specialPageAliases['arc'] = array(
-	'CategoryTree' => array( 'ܐܝܠܢܐ_ܕܣܕܪܐ' ),
-);
+$specialPageAliases['arc'] = [
+	'CategoryTree' => [ 'ܐܝܠܢܐ_ܕܣܕܪܐ' ],
+];
 
 /** Egyptian Arabic (مصرى) */
-$specialPageAliases['arz'] = array(
-	'CategoryTree' => array( 'شجرة_تصنيف' ),
-);
+$specialPageAliases['arz'] = [
+	'CategoryTree' => [ 'شجرة_تصنيف' ],
+];
 
 /** Assamese (অসমীয়া) */
-$specialPageAliases['as'] = array(
-	'CategoryTree' => array( 'শ্ৰেণীবৃক্ষ' ),
-);
+$specialPageAliases['as'] = [
+	'CategoryTree' => [ 'শ্ৰেণীবৃক্ষ' ],
+];
 
 /** Avaric (авар) */
-$specialPageAliases['av'] = array(
-	'CategoryTree' => array( 'Категориязул_гъветІ' ),
-);
+$specialPageAliases['av'] = [
+	'CategoryTree' => [ 'Категориязул_гъветІ' ],
+];
 
 /** Bashkir (башҡортса) */
-$specialPageAliases['ba'] = array(
-	'CategoryTree' => array( 'Категория_ағасы' ),
-);
+$specialPageAliases['ba'] = [
+	'CategoryTree' => [ 'Категория_ағасы' ],
+];
 
 /** Bikol Central (Bikol Central) */
-$specialPageAliases['bcl'] = array(
-	'CategoryTree' => array( 'KahoyNinKategorya' ),
-);
+$specialPageAliases['bcl'] = [
+	'CategoryTree' => [ 'KahoyNinKategorya' ],
+];
 
 /** Belarusian (Taraškievica orthography) (беларуская (тарашкевіца)‎) */
-$specialPageAliases['be-tarask'] = array(
-	'CategoryTree' => array( 'Дрэва_катэгорыяў' ),
-);
+$specialPageAliases['be-tarask'] = [
+	'CategoryTree' => [ 'Дрэва_катэгорыяў' ],
+];
 
 /** Bulgarian (български) */
-$specialPageAliases['bg'] = array(
-	'CategoryTree' => array( 'Дърво_на_категориите' ),
-);
+$specialPageAliases['bg'] = [
+	'CategoryTree' => [ 'Дърво_на_категориите' ],
+];
 
 /** Western Balochi (بلوچی رخشانی) */
-$specialPageAliases['bgn'] = array(
-	'CategoryTree' => array( 'تهری_درچّگ_یا_درخت' ),
-);
+$specialPageAliases['bgn'] = [
+	'CategoryTree' => [ 'تهری_درچّگ_یا_درخت' ],
+];
 
 /** Banjar (Bahasa Banjar) */
-$specialPageAliases['bjn'] = array(
-	'CategoryTree' => array( 'Puhun_tumbung' ),
-);
+$specialPageAliases['bjn'] = [
+	'CategoryTree' => [ 'Puhun_tumbung' ],
+];
 
 /** Breton (brezhoneg) */
-$specialPageAliases['br'] = array(
-	'CategoryTree' => array( 'GwezennadurRummad' ),
-);
+$specialPageAliases['br'] = [
+	'CategoryTree' => [ 'GwezennadurRummad' ],
+];
 
 /** Bosnian (bosanski) */
-$specialPageAliases['bs'] = array(
-	'CategoryTree' => array( 'StabloKategorija' ),
-);
+$specialPageAliases['bs'] = [
+	'CategoryTree' => [ 'StabloKategorija' ],
+];
 
 /** Catalan (català) */
-$specialPageAliases['ca'] = array(
-	'CategoryTree' => array( 'Categories_en_arbre', 'Arbre_de_categories' ),
-);
+$specialPageAliases['ca'] = [
+	'CategoryTree' => [ 'Categories_en_arbre', 'Arbre_de_categories' ],
+];
 
 /** Min Dong Chinese (Mìng-dĕ̤ng-ngṳ̄) */
-$specialPageAliases['cdo'] = array(
-	'CategoryTree' => array( '分類樹' ),
-);
+$specialPageAliases['cdo'] = [
+	'CategoryTree' => [ '分類樹' ],
+];
 
 /** Chechen (нохчийн) */
-$specialPageAliases['ce'] = array(
-	'CategoryTree' => array( 'Категорийн_дит' ),
-);
+$specialPageAliases['ce'] = [
+	'CategoryTree' => [ 'Категорийн_дит' ],
+];
 
 /** Czech (čeština) */
-$specialPageAliases['cs'] = array(
-	'CategoryTree' => array( 'Strom_kategorií' ),
-);
+$specialPageAliases['cs'] = [
+	'CategoryTree' => [ 'Strom_kategorií' ],
+];
 
 /** Danish (dansk) */
-$specialPageAliases['da'] = array(
-	'CategoryTree' => array( 'Kategoritræ' ),
-);
+$specialPageAliases['da'] = [
+	'CategoryTree' => [ 'Kategoritræ' ],
+];
 
 /** German (Deutsch) */
-$specialPageAliases['de'] = array(
-	'CategoryTree' => array( 'Kategorienbaum', 'Kategoriebaum' ),
-);
+$specialPageAliases['de'] = [
+	'CategoryTree' => [ 'Kategorienbaum', 'Kategoriebaum' ],
+];
 
 /** Zazaki (Zazaki) */
-$specialPageAliases['diq'] = array(
-	'CategoryTree' => array( 'DaraKategoriye' ),
-);
+$specialPageAliases['diq'] = [
+	'CategoryTree' => [ 'DaraKategoriye' ],
+];
 
 /** Lower Sorbian (dolnoserbski) */
-$specialPageAliases['dsb'] = array(
-	'CategoryTree' => array( 'Bom_kategorijow' ),
-);
+$specialPageAliases['dsb'] = [
+	'CategoryTree' => [ 'Bom_kategorijow' ],
+];
 
 /** Greek (Ελληνικά) */
-$specialPageAliases['el'] = array(
-	'CategoryTree' => array( 'ΔέντροΚατηγορίας' ),
-);
+$specialPageAliases['el'] = [
+	'CategoryTree' => [ 'ΔέντροΚατηγορίας' ],
+];
 
 /** Esperanto (Esperanto) */
-$specialPageAliases['eo'] = array(
-	'CategoryTree' => array( 'Arbo_de_kategorioj', 'Kategorio-arbo' ),
-);
+$specialPageAliases['eo'] = [
+	'CategoryTree' => [ 'Arbo_de_kategorioj', 'Kategorio-arbo' ],
+];
 
 /** Spanish (español) */
-$specialPageAliases['es'] = array(
-	'CategoryTree' => array( 'ÁrbolDeCategorías', 'Árbol_de_categorías' ),
-);
+$specialPageAliases['es'] = [
+	'CategoryTree' => [ 'ÁrbolDeCategorías', 'Árbol_de_categorías' ],
+];
 
 /** Estonian (eesti) */
-$specialPageAliases['et'] = array(
-	'CategoryTree' => array( 'Kategooriapuu' ),
-);
+$specialPageAliases['et'] = [
+	'CategoryTree' => [ 'Kategooriapuu' ],
+];
 
 /** Basque (euskara) */
-$specialPageAliases['eu'] = array(
-	'CategoryTree' => array( 'KategoriaZuhaitza' ),
-);
+$specialPageAliases['eu'] = [
+	'CategoryTree' => [ 'KategoriaZuhaitza' ],
+];
 
 /** Persian (فارسی) */
-$specialPageAliases['fa'] = array(
-	'CategoryTree' => array( 'درخت_رده' ),
-);
+$specialPageAliases['fa'] = [
+	'CategoryTree' => [ 'درخت_رده' ],
+];
 
 /** Finnish (suomi) */
-$specialPageAliases['fi'] = array(
-	'CategoryTree' => array( 'Luokkapuu' ),
-);
+$specialPageAliases['fi'] = [
+	'CategoryTree' => [ 'Luokkapuu' ],
+];
 
 /** French (français) */
-$specialPageAliases['fr'] = array(
-	'CategoryTree' => array( 'ArbreCatégorie', 'ArbreCategorie', 'Arbre_catégorie' ),
-);
+$specialPageAliases['fr'] = [
+	'CategoryTree' => [ 'ArbreCatégorie', 'ArbreCategorie', 'Arbre_catégorie' ],
+];
 
 /** Arpitan (arpetan) */
-$specialPageAliases['frp'] = array(
-	'CategoryTree' => array( 'Structura_d\'âbro_de_les_catègories', 'StructuraDÂbroDeLesCatègories' ),
-);
+$specialPageAliases['frp'] = [
+	'CategoryTree' => [ 'Structura_d\'âbro_de_les_catègories', 'StructuraDÂbroDeLesCatègories' ],
+];
 
 /** Western Frisian (Frysk) */
-$specialPageAliases['fy'] = array(
-	'CategoryTree' => array( 'Kategorybeam' ),
-);
+$specialPageAliases['fy'] = [
+	'CategoryTree' => [ 'Kategorybeam' ],
+];
 
 /** Galician (galego) */
-$specialPageAliases['gl'] = array(
-	'CategoryTree' => array( 'Árbore_de_categorías' ),
-);
+$specialPageAliases['gl'] = [
+	'CategoryTree' => [ 'Árbore_de_categorías' ],
+];
 
 /** Swiss German (Alemannisch) */
-$specialPageAliases['gsw'] = array(
-	'CategoryTree' => array( 'Kategoriebaum' ),
-);
+$specialPageAliases['gsw'] = [
+	'CategoryTree' => [ 'Kategoriebaum' ],
+];
 
 /** Gujarati (ગુજરાતી) */
-$specialPageAliases['gu'] = array(
-	'CategoryTree' => array( 'શ્રેણીવૃક્ષ' ),
-);
+$specialPageAliases['gu'] = [
+	'CategoryTree' => [ 'શ્રેણીવૃક્ષ' ],
+];
 
 /** Hebrew (עברית) */
-$specialPageAliases['he'] = array(
-	'CategoryTree' => array( 'עץ_קטגוריות' ),
-);
+$specialPageAliases['he'] = [
+	'CategoryTree' => [ 'עץ_קטגוריות' ],
+];
 
 /** Hindi (हिन्दी) */
-$specialPageAliases['hi'] = array(
-	'CategoryTree' => array( 'श्रेणी_वृक्ष', 'श्रेणीवृक्ष' ),
-);
+$specialPageAliases['hi'] = [
+	'CategoryTree' => [ 'श्रेणी_वृक्ष', 'श्रेणीवृक्ष' ],
+];
 
 /** Upper Sorbian (hornjoserbsce) */
-$specialPageAliases['hsb'] = array(
-	'CategoryTree' => array( 'Kategorijowy_štom' ),
-);
+$specialPageAliases['hsb'] = [
+	'CategoryTree' => [ 'Kategorijowy_štom' ],
+];
 
 /** Xiang Chinese (湘语) */
-$specialPageAliases['hsn'] = array(
-	'CategoryTree' => array( '类别树' ),
-);
+$specialPageAliases['hsn'] = [
+	'CategoryTree' => [ '类别树' ],
+];
 
 /** Haitian (Kreyòl ayisyen) */
-$specialPageAliases['ht'] = array(
-	'CategoryTree' => array( 'NivoKategori' ),
-);
+$specialPageAliases['ht'] = [
+	'CategoryTree' => [ 'NivoKategori' ],
+];
 
 /** Hungarian (magyar) */
-$specialPageAliases['hu'] = array(
-	'CategoryTree' => array( 'Kategóriafa' ),
-);
+$specialPageAliases['hu'] = [
+	'CategoryTree' => [ 'Kategóriafa' ],
+];
 
 /** Interlingua (interlingua) */
-$specialPageAliases['ia'] = array(
-	'CategoryTree' => array( 'Arbore_de_categorias' ),
-);
+$specialPageAliases['ia'] = [
+	'CategoryTree' => [ 'Arbore_de_categorias' ],
+];
 
 /** Indonesian (Bahasa Indonesia) */
-$specialPageAliases['id'] = array(
-	'CategoryTree' => array( 'Pohon_kategori', 'PohonKategori' ),
-);
+$specialPageAliases['id'] = [
+	'CategoryTree' => [ 'Pohon_kategori', 'PohonKategori' ],
+];
 
 /** Ido (Ido) */
-$specialPageAliases['io'] = array(
-	'CategoryTree' => array( 'KategorioArboro' ),
-);
+$specialPageAliases['io'] = [
+	'CategoryTree' => [ 'KategorioArboro' ],
+];
 
 /** Italian (italiano) */
-$specialPageAliases['it'] = array(
-	'CategoryTree' => array( 'AlberoCategorie' ),
-);
+$specialPageAliases['it'] = [
+	'CategoryTree' => [ 'AlberoCategorie' ],
+];
 
 /** Japanese (日本語) */
-$specialPageAliases['ja'] = array(
-	'CategoryTree' => array( 'カテゴリツリー' ),
-);
+$specialPageAliases['ja'] = [
+	'CategoryTree' => [ 'カテゴリツリー' ],
+];
 
 /** Georgian (ქართული) */
-$specialPageAliases['ka'] = array(
-	'CategoryTree' => array( 'კატეგორიის_ხე' ),
-);
+$specialPageAliases['ka'] = [
+	'CategoryTree' => [ 'კატეგორიის_ხე' ],
+];
 
 /** Khmer (ភាសាខ្មែរ) */
-$specialPageAliases['km'] = array(
-	'CategoryTree' => array( 'មែកធាងចំណាត់ថ្នាក់ក្រុម' ),
-);
+$specialPageAliases['km'] = [
+	'CategoryTree' => [ 'មែកធាងចំណាត់ថ្នាក់ក្រុម' ],
+];
 
 /** Korean (한국어) */
-$specialPageAliases['ko'] = array(
-	'CategoryTree' => array( '분류트리' ),
-);
+$specialPageAliases['ko'] = [
+	'CategoryTree' => [ '분류트리' ],
+];
 
 /** Colognian (Ripoarisch) */
-$specialPageAliases['ksh'] = array(
-	'CategoryTree' => array( 'Saachjruppeboum' ),
-);
+$specialPageAliases['ksh'] = [
+	'CategoryTree' => [ 'Saachjruppeboum' ],
+];
 
 /** Kurdish (Kurdî) */
-$specialPageAliases['ku'] = array(
-	'CategoryTree' => array( 'Dara_kategoriyan' ),
-);
+$specialPageAliases['ku'] = [
+	'CategoryTree' => [ 'Dara_kategoriyan' ],
+];
 
 /** Cornish (kernowek) */
-$specialPageAliases['kw'] = array(
-	'CategoryTree' => array( 'GwedhenGlassys' ),
-);
+$specialPageAliases['kw'] = [
+	'CategoryTree' => [ 'GwedhenGlassys' ],
+];
 
 /** Latin (Latina) */
-$specialPageAliases['la'] = array(
-	'CategoryTree' => array( 'Categoriarum_arbor' ),
-);
+$specialPageAliases['la'] = [
+	'CategoryTree' => [ 'Categoriarum_arbor' ],
+];
 
 /** Ladino (Ladino) */
-$specialPageAliases['lad'] = array(
-	'CategoryTree' => array( 'Árvole_de_Kateggorías' ),
-);
+$specialPageAliases['lad'] = [
+	'CategoryTree' => [ 'Árvole_de_Kateggorías' ],
+];
 
 /** Luxembourgish (Lëtzebuergesch) */
-$specialPageAliases['lb'] = array(
-	'CategoryTree' => array( 'Struktur_vun_de_Kategorien' ),
-);
+$specialPageAliases['lb'] = [
+	'CategoryTree' => [ 'Struktur_vun_de_Kategorien' ],
+];
 
 /** Northern Luri (لۊری شومالی) */
-$specialPageAliases['lrc'] = array(
-	'CategoryTree' => array( 'دار_دأسە' ),
-);
+$specialPageAliases['lrc'] = [
+	'CategoryTree' => [ 'دار_دأسە' ],
+];
 
 /** Malagasy (Malagasy) */
-$specialPageAliases['mg'] = array(
-	'CategoryTree' => array( 'Hazon-tsokajy', 'Hazontsokajy' ),
-);
+$specialPageAliases['mg'] = [
+	'CategoryTree' => [ 'Hazon-tsokajy', 'Hazontsokajy' ],
+];
 
 /** Minangkabau (Baso Minangkabau) */
-$specialPageAliases['min'] = array(
-	'CategoryTree' => array( 'BatangKategori' ),
-);
+$specialPageAliases['min'] = [
+	'CategoryTree' => [ 'BatangKategori' ],
+];
 
 /** Macedonian (македонски) */
-$specialPageAliases['mk'] = array(
-	'CategoryTree' => array( 'ДрвоНаКатегории' ),
-);
+$specialPageAliases['mk'] = [
+	'CategoryTree' => [ 'ДрвоНаКатегории' ],
+];
 
 /** Malayalam (മലയാളം) */
-$specialPageAliases['ml'] = array(
-	'CategoryTree' => array( 'വർഗ്ഗവൃക്ഷം' ),
-);
+$specialPageAliases['ml'] = [
+	'CategoryTree' => [ 'വർഗ്ഗവൃക്ഷം' ],
+];
 
 /** Marathi (मराठी) */
-$specialPageAliases['mr'] = array(
-	'CategoryTree' => array( 'वर्गवृक्ष' ),
-);
+$specialPageAliases['mr'] = [
+	'CategoryTree' => [ 'वर्गवृक्ष' ],
+];
 
 /** Malay (Bahasa Melayu) */
-$specialPageAliases['ms'] = array(
-	'CategoryTree' => array( 'Salasilah_kategori' ),
-);
+$specialPageAliases['ms'] = [
+	'CategoryTree' => [ 'Salasilah_kategori' ],
+];
 
 /** Maltese (Malti) */
-$specialPageAliases['mt'] = array(
-	'CategoryTree' => array( 'SiġraKategorija' ),
-);
+$specialPageAliases['mt'] = [
+	'CategoryTree' => [ 'SiġraKategorija' ],
+];
 
 /** Erzya (эрзянь) */
-$specialPageAliases['myv'] = array(
-	'CategoryTree' => array( 'КатегорияньЧувто' ),
-);
+$specialPageAliases['myv'] = [
+	'CategoryTree' => [ 'КатегорияньЧувто' ],
+];
 
 /** Norwegian Bokmål (norsk bokmål) */
-$specialPageAliases['nb'] = array(
-	'CategoryTree' => array( 'Kategoritre' ),
-);
+$specialPageAliases['nb'] = [
+	'CategoryTree' => [ 'Kategoritre' ],
+];
 
 /** Low German (Plattdüütsch) */
-$specialPageAliases['nds'] = array(
-	'CategoryTree' => array( 'Kategorieboom' ),
-);
+$specialPageAliases['nds'] = [
+	'CategoryTree' => [ 'Kategorieboom' ],
+];
 
 /** Low Saxon (Netherlands) (Nedersaksies) */
-$specialPageAliases['nds-nl'] = array(
-	'CategoryTree' => array( 'Kategorieboom' ),
-);
+$specialPageAliases['nds-nl'] = [
+	'CategoryTree' => [ 'Kategorieboom' ],
+];
 
 /** Dutch (Nederlands) */
-$specialPageAliases['nl'] = array(
-	'CategoryTree' => array( 'Categorieboom' ),
-);
+$specialPageAliases['nl'] = [
+	'CategoryTree' => [ 'Categorieboom' ],
+];
 
 /** Norwegian Nynorsk (norsk nynorsk) */
-$specialPageAliases['nn'] = array(
-	'CategoryTree' => array( 'Kategoritre' ),
-);
+$specialPageAliases['nn'] = [
+	'CategoryTree' => [ 'Kategoritre' ],
+];
 
 /** Occitan (occitan) */
-$specialPageAliases['oc'] = array(
-	'CategoryTree' => array( 'ArbreCategoria', 'Arbre_categoria' ),
-);
+$specialPageAliases['oc'] = [
+	'CategoryTree' => [ 'ArbreCategoria', 'Arbre_categoria' ],
+];
 
 /** Polish (polski) */
-$specialPageAliases['pl'] = array(
-	'CategoryTree' => array( 'Drzewo_kategorii' ),
-);
+$specialPageAliases['pl'] = [
+	'CategoryTree' => [ 'Drzewo_kategorii' ],
+];
 
 /** Pashto (پښتو) */
-$specialPageAliases['ps'] = array(
-	'CategoryTree' => array( 'د_وېشنيزو_ونه' ),
-);
+$specialPageAliases['ps'] = [
+	'CategoryTree' => [ 'د_وېشنيزو_ونه' ],
+];
 
 /** Portuguese (português) */
-$specialPageAliases['pt'] = array(
-	'CategoryTree' => array( 'Árvore_de_categorias' ),
-);
+$specialPageAliases['pt'] = [
+	'CategoryTree' => [ 'Árvore_de_categorias' ],
+];
 
 /** Brazilian Portuguese (português do Brasil) */
-$specialPageAliases['pt-br'] = array(
-	'CategoryTree' => array( 'Árvore_de_categorias', 'Árvore_de_categoria' ),
-);
+$specialPageAliases['pt-br'] = [
+	'CategoryTree' => [ 'Árvore_de_categorias', 'Árvore_de_categoria' ],
+];
 
 /** Romanian (română) */
-$specialPageAliases['ro'] = array(
-	'CategoryTree' => array( 'Arborele_categoriilor' ),
-);
+$specialPageAliases['ro'] = [
+	'CategoryTree' => [ 'Arborele_categoriilor' ],
+];
 
 /** Russian (русский) */
-$specialPageAliases['ru'] = array(
-	'CategoryTree' => array( 'Дерево_категорий' ),
-);
+$specialPageAliases['ru'] = [
+	'CategoryTree' => [ 'Дерево_категорий' ],
+];
 
 /** Sanskrit (संस्कृतम्) */
-$specialPageAliases['sa'] = array(
-	'CategoryTree' => array( 'वर्गवृक्ष:' ),
-);
+$specialPageAliases['sa'] = [
+	'CategoryTree' => [ 'वर्गवृक्ष:' ],
+];
 
 /** Sicilian (sicilianu) */
-$specialPageAliases['scn'] = array(
-	'CategoryTree' => array( 'AlberoCategorie' ),
-);
+$specialPageAliases['scn'] = [
+	'CategoryTree' => [ 'AlberoCategorie' ],
+];
 
 /** Sinhala (සිංහල) */
-$specialPageAliases['si'] = array(
-	'CategoryTree' => array( 'ප්‍රවර්ගරුක' ),
-);
+$specialPageAliases['si'] = [
+	'CategoryTree' => [ 'ප්‍රවර්ගරුක' ],
+];
 
 /** Slovak (slovenčina) */
-$specialPageAliases['sk'] = array(
-	'CategoryTree' => array( 'StromKategórií' ),
-);
+$specialPageAliases['sk'] = [
+	'CategoryTree' => [ 'StromKategórií' ],
+];
 
 /** Swedish (svenska) */
-$specialPageAliases['sv'] = array(
-	'CategoryTree' => array( 'Kategoriträd' ),
-);
+$specialPageAliases['sv'] = [
+	'CategoryTree' => [ 'Kategoriträd' ],
+];
 
 /** Swahili (Kiswahili) */
-$specialPageAliases['sw'] = array(
-	'CategoryTree' => array( 'SafuyaJamii' ),
-);
+$specialPageAliases['sw'] = [
+	'CategoryTree' => [ 'SafuyaJamii' ],
+];
 
 /** Telugu (తెలుగు) */
-$specialPageAliases['te'] = array(
-	'CategoryTree' => array( 'వర్గవృక్షం' ),
-);
+$specialPageAliases['te'] = [
+	'CategoryTree' => [ 'వర్గవృక్షం' ],
+];
 
 /** Thai (ไทย) */
-$specialPageAliases['th'] = array(
-	'CategoryTree' => array( 'หมวดหมู่แบบผังต้นไม้' ),
-);
+$specialPageAliases['th'] = [
+	'CategoryTree' => [ 'หมวดหมู่แบบผังต้นไม้' ],
+];
 
 /** Tagalog (Tagalog) */
-$specialPageAliases['tl'] = array(
-	'CategoryTree' => array( 'Puno_ng_kaurian' ),
-);
+$specialPageAliases['tl'] = [
+	'CategoryTree' => [ 'Puno_ng_kaurian' ],
+];
 
 /** Talysh (толышә зывон) */
-$specialPageAliases['tly'] = array(
-	'CategoryTree' => array( 'Категоријон_до' ),
-);
+$specialPageAliases['tly'] = [
+	'CategoryTree' => [ 'Категоријон_до' ],
+];
 
 /** Turkish (Türkçe) */
-$specialPageAliases['tr'] = array(
-	'CategoryTree' => array( 'KategoriAğacı', 'KategoriHiyerarşisi', 'UlamAğacı', 'UlamHiyerarşisi' ),
-);
+$specialPageAliases['tr'] = [
+	'CategoryTree' => [ 'KategoriAğacı', 'KategoriHiyerarşisi', 'UlamAğacı', 'UlamHiyerarşisi' ],
+];
 
 /** Ukrainian (українська) */
-$specialPageAliases['uk'] = array(
-	'CategoryTree' => array( 'Дерево_категорій' ),
-);
+$specialPageAliases['uk'] = [
+	'CategoryTree' => [ 'Дерево_категорій' ],
+];
 
 /** Urdu (اردو) */
-$specialPageAliases['ur'] = array(
-	'CategoryTree' => array( 'شجرہ_زمرہ' ),
-);
+$specialPageAliases['ur'] = [
+	'CategoryTree' => [ 'شجرہ_زمرہ' ],
+];
 
 /** Venetian (vèneto) */
-$specialPageAliases['vec'] = array(
-	'CategoryTree' => array( 'ÀlbaroCategorie' ),
-);
+$specialPageAliases['vec'] = [
+	'CategoryTree' => [ 'ÀlbaroCategorie' ],
+];
 
 /** Veps (vepsän kel’) */
-$specialPageAliases['vep'] = array(
-	'CategoryTree' => array( 'KategorijoidenPu' ),
-);
+$specialPageAliases['vep'] = [
+	'CategoryTree' => [ 'KategorijoidenPu' ],
+];
 
 /** Vietnamese (Tiếng Việt) */
-$specialPageAliases['vi'] = array(
-	'CategoryTree' => array( 'Cây_thể_loại' ),
-);
+$specialPageAliases['vi'] = [
+	'CategoryTree' => [ 'Cây_thể_loại' ],
+];
 
 /** Yiddish (ייִדיש) */
-$specialPageAliases['yi'] = array(
-	'CategoryTree' => array( 'קאטעגאריע_בוים' ),
-);
+$specialPageAliases['yi'] = [
+	'CategoryTree' => [ 'קאטעגאריע_בוים' ],
+];
 
 /** Simplified Chinese (中文（简体）‎) */
-$specialPageAliases['zh-hans'] = array(
-	'CategoryTree' => array( '分类树' ),
-);
+$specialPageAliases['zh-hans'] = [
+	'CategoryTree' => [ '分类树' ],
+];
 
 /** Traditional Chinese (中文（繁體）‎) */
-$specialPageAliases['zh-hant'] = array(
-	'CategoryTree' => array( '分類樹' ),
-);
+$specialPageAliases['zh-hant'] = [
+	'CategoryTree' => [ '分類樹' ],
+];
 
 /** Chinese (Taiwan) (中文（台灣）‎) */
-$specialPageAliases['zh-tw'] = array(
-	'CategoryTree' => array( '分類樹' ),
-);
\ No newline at end of file
+$specialPageAliases['zh-tw'] = [
+	'CategoryTree' => [ '分類樹' ],
+];
diff --git a/CategoryTree.hooks.php b/CategoryTree.hooks.php
index aa0c0fef..d5c05cee 100644
--- a/CategoryTree.hooks.php
+++ b/CategoryTree.hooks.php
@@ -90,7 +90,7 @@ class CategoryTreeHooks {
 		$cat = array_shift( $params );
 
 		// build associative arguments from flat parameter list
-		$argv = array();
+		$argv = [];
 		foreach ( $params as $p ) {
 			if ( preg_match( '/^\s*(\S.*?)\s*=\s*(.*?)\s*$/', $p, $m ) ) {
 				$k = $m[1];
@@ -105,7 +105,7 @@ class CategoryTreeHooks {
 
 		// now handle just like a <categorytree> tag
 		$html = self::parserHook( $cat, $argv, $parser );
-		return array( $html, 'noparse' => true, 'isHTML' => true );
+		return [ $html, 'noparse' => true, 'isHTML' => true ];
 	}
 
 	/**
diff --git a/CategoryTree.i18n.magic.php b/CategoryTree.i18n.magic.php
index 423f3fa7..00bc553c 100644
--- a/CategoryTree.i18n.magic.php
+++ b/CategoryTree.i18n.magic.php
@@ -9,249 +9,249 @@
  * @license GNU General Public Licence 2.0 or later
  */
 
-$magicWords = array();
+$magicWords = [];
 
 /** English (English) */
-$magicWords['en'] = array(
-	'categorytree' => array( 0, 'categorytree' ),
-);
+$magicWords['en'] = [
+	'categorytree' => [ 0, 'categorytree' ],
+];
 
 /** Afrikaans (Afrikaans) */
-$magicWords['af'] = array(
-	'categorytree' => array( 0, 'kategorieboom', 'categorytree' ),
-);
+$magicWords['af'] = [
+	'categorytree' => [ 0, 'kategorieboom', 'categorytree' ],
+];
 
 /** Arabic (العربية) */
-$magicWords['ar'] = array(
-	'categorytree' => array( 0, 'شجرة_تصنيف' ),
-);
+$magicWords['ar'] = [
+	'categorytree' => [ 0, 'شجرة_تصنيف' ],
+];
 
 /** Egyptian Arabic (مصرى) */
-$magicWords['arz'] = array(
-	'categorytree' => array( 0, 'شجرة_تصنيف' ),
-);
+$magicWords['arz'] = [
+	'categorytree' => [ 0, 'شجرة_تصنيف' ],
+];
 
 /** Breton (brezhoneg) */
-$magicWords['br'] = array(
-	'categorytree' => array( 0, 'GwezennadurRummad' ),
-);
+$magicWords['br'] = [
+	'categorytree' => [ 0, 'GwezennadurRummad' ],
+];
 
 /** Chechen (нохчийн) */
-$magicWords['ce'] = array(
-	'categorytree' => array( 0, 'категоридит', 'деревокатегорий' ),
-);
+$magicWords['ce'] = [
+	'categorytree' => [ 0, 'категоридит', 'деревокатегорий' ],
+];
 
 /** German (Deutsch) */
-$magicWords['de'] = array(
-	'categorytree' => array( 0, 'kategorienbaum', 'kategoriebaum' ),
-);
+$magicWords['de'] = [
+	'categorytree' => [ 0, 'kategorienbaum', 'kategoriebaum' ],
+];
 
 /** Zazaki (Zazaki) */
-$magicWords['diq'] = array(
-	'categorytree' => array( 0, 'darakategori' ),
-);
+$magicWords['diq'] = [
+	'categorytree' => [ 0, 'darakategori' ],
+];
 
 /** Esperanto (Esperanto) */
-$magicWords['eo'] = array(
-	'categorytree' => array( 0, 'kategoriarbo' ),
-);
+$magicWords['eo'] = [
+	'categorytree' => [ 0, 'kategoriarbo' ],
+];
 
 /** Spanish (español) */
-$magicWords['es'] = array(
-	'categorytree' => array( 0, 'árboldecategorías', 'arboldecategorias' ),
-);
+$magicWords['es'] = [
+	'categorytree' => [ 0, 'árboldecategorías', 'arboldecategorias' ],
+];
 
 /** Estonian (eesti) */
-$magicWords['et'] = array(
-	'categorytree' => array( 0, 'kategooriapuu' ),
-);
+$magicWords['et'] = [
+	'categorytree' => [ 0, 'kategooriapuu' ],
+];
 
 /** Persian (فارسی) */
-$magicWords['fa'] = array(
-	'categorytree' => array( 0, 'درخت‌رده', 'درخت_رده' ),
-);
+$magicWords['fa'] = [
+	'categorytree' => [ 0, 'درخت‌رده', 'درخت_رده' ],
+];
 
 /** French (français) */
-$magicWords['fr'] = array(
-	'categorytree' => array( 0, 'arbrecatégories', 'arbrecats' ),
-);
+$magicWords['fr'] = [
+	'categorytree' => [ 0, 'arbrecatégories', 'arbrecats' ],
+];
 
 /** Western Frisian (Frysk) */
-$magicWords['fy'] = array(
-	'categorytree' => array( 0, 'kategorybeam' ),
-);
+$magicWords['fy'] = [
+	'categorytree' => [ 0, 'kategorybeam' ],
+];
 
 /** Galician (galego) */
-$magicWords['gl'] = array(
-	'categorytree' => array( 0, 'árboredecategorías' ),
-);
+$magicWords['gl'] = [
+	'categorytree' => [ 0, 'árboredecategorías' ],
+];
 
 /** Hebrew (עברית) */
-$magicWords['he'] = array(
-	'categorytree' => array( 0, 'עץ_קטגוריה' ),
-);
+$magicWords['he'] = [
+	'categorytree' => [ 0, 'עץ_קטגוריה' ],
+];
 
 /** Hindi (हिन्दी) */
-$magicWords['hi'] = array(
-	'categorytree' => array( 0, 'श्रेणी_वृक्ष' ),
-);
+$magicWords['hi'] = [
+	'categorytree' => [ 0, 'श्रेणी_वृक्ष' ],
+];
 
 /** Igbo (Igbo) */
-$magicWords['ig'] = array(
-	'categorytree' => array( 0, 'óshíshíébéonọr', 'categorytree' ),
-);
+$magicWords['ig'] = [
+	'categorytree' => [ 0, 'óshíshíébéonọr', 'categorytree' ],
+];
 
 /** Italian (italiano) */
-$magicWords['it'] = array(
-	'categorytree' => array( 0, 'alberocategorie' ),
-);
+$magicWords['it'] = [
+	'categorytree' => [ 0, 'alberocategorie' ],
+];
 
 /** Japanese (日本語) */
-$magicWords['ja'] = array(
-	'categorytree' => array( 0, 'カテゴリツリー' ),
-);
+$magicWords['ja'] = [
+	'categorytree' => [ 0, 'カテゴリツリー' ],
+];
 
 /** Georgian (ქართული) */
-$magicWords['ka'] = array(
-	'categorytree' => array( 0, 'კატეგორიის_ხე' ),
-);
+$magicWords['ka'] = [
+	'categorytree' => [ 0, 'კატეგორიის_ხე' ],
+];
 
 /** Korean (한국어) */
-$magicWords['ko'] = array(
-	'categorytree' => array( 0, '분류트리' ),
-);
+$magicWords['ko'] = [
+	'categorytree' => [ 0, '분류트리' ],
+];
 
 /** Kurdish (Latin script) (Kurdî (latînî)‎) */
-$magicWords['ku-latn'] = array(
-	'categorytree' => array( 0, 'dara_kategoriyan' ),
-);
+$magicWords['ku-latn'] = [
+	'categorytree' => [ 0, 'dara_kategoriyan' ],
+];
 
 /** Cornish (kernowek) */
-$magicWords['kw'] = array(
-	'categorytree' => array( 0, 'gwedhenglass' ),
-);
+$magicWords['kw'] = [
+	'categorytree' => [ 0, 'gwedhenglass' ],
+];
 
 /** Ladino (Ladino) */
-$magicWords['lad'] = array(
-	'categorytree' => array( 0, 'árvoledekateggorías', 'árboldecategorías', 'arboldecategorias', 'categorytree' ),
-);
+$magicWords['lad'] = [
+	'categorytree' => [ 0, 'árvoledekateggorías', 'árboldecategorías', 'arboldecategorias', 'categorytree' ],
+];
 
 /** Malagasy (Malagasy) */
-$magicWords['mg'] = array(
-	'categorytree' => array( 0, 'karazantsokajy', 'categorytree' ),
-);
+$magicWords['mg'] = [
+	'categorytree' => [ 0, 'karazantsokajy', 'categorytree' ],
+];
 
 /** Macedonian (македонски) */
-$magicWords['mk'] = array(
-	'categorytree' => array( 0, 'стеблонакатегории' ),
-);
+$magicWords['mk'] = [
+	'categorytree' => [ 0, 'стеблонакатегории' ],
+];
 
 /** Malayalam (മലയാളം) */
-$magicWords['ml'] = array(
-	'categorytree' => array( 0, 'വർഗ്ഗവൃക്ഷം' ),
-);
+$magicWords['ml'] = [
+	'categorytree' => [ 0, 'വർഗ്ഗവൃക്ഷം' ],
+];
 
 /** Marathi (मराठी) */
-$magicWords['mr'] = array(
-	'categorytree' => array( 0, 'वर्गवृक्ष' ),
-);
+$magicWords['mr'] = [
+	'categorytree' => [ 0, 'वर्गवृक्ष' ],
+];
 
 /** Norwegian Bokmål (norsk bokmål) */
-$magicWords['nb'] = array(
-	'categorytree' => array( 0, 'kategoritre' ),
-);
+$magicWords['nb'] = [
+	'categorytree' => [ 0, 'kategoritre' ],
+];
 
 /** Low Saxon (Netherlands) (Nedersaksies) */
-$magicWords['nds-nl'] = array(
-	'categorytree' => array( 0, 'kategorieboom', 'categorieboom' ),
-);
+$magicWords['nds-nl'] = [
+	'categorytree' => [ 0, 'kategorieboom', 'categorieboom' ],
+];
 
 /** Dutch (Nederlands) */
-$magicWords['nl'] = array(
-	'categorytree' => array( 0, 'categorieboom' ),
-);
+$magicWords['nl'] = [
+	'categorytree' => [ 0, 'categorieboom' ],
+];
 
 /** Norwegian Nynorsk (norsk nynorsk) */
-$magicWords['nn'] = array(
-	'categorytree' => array( 0, 'kategoritre' ),
-);
+$magicWords['nn'] = [
+	'categorytree' => [ 0, 'kategoritre' ],
+];
 
 /** Polish (polski) */
-$magicWords['pl'] = array(
-	'categorytree' => array( 0, 'drzewokategorii' ),
-);
+$magicWords['pl'] = [
+	'categorytree' => [ 0, 'drzewokategorii' ],
+];
 
 /** Romanian (română) */
-$magicWords['ro'] = array(
-	'categorytree' => array( 0, 'arborecategorie' ),
-);
+$magicWords['ro'] = [
+	'categorytree' => [ 0, 'arborecategorie' ],
+];
 
 /** Russian (русский) */
-$magicWords['ru'] = array(
-	'categorytree' => array( 0, 'деревокатегорий' ),
-);
+$magicWords['ru'] = [
+	'categorytree' => [ 0, 'деревокатегорий' ],
+];
 
 /** Serbian (Cyrillic script) (српски (ћирилица)‎) */
-$magicWords['sr-ec'] = array(
-	'categorytree' => array( 0, 'стаблокатегорије', 'стабло_категорије' ),
-);
+$magicWords['sr-ec'] = [
+	'categorytree' => [ 0, 'стаблокатегорије', 'стабло_категорије' ],
+];
 
 /** Serbian (Latin script) (srpski (latinica)‎) */
-$magicWords['sr-el'] = array(
-	'categorytree' => array( 0, 'stablokategorije', 'stablo_kategorije' ),
-);
+$magicWords['sr-el'] = [
+	'categorytree' => [ 0, 'stablokategorije', 'stablo_kategorije' ],
+];
 
 /** Swedish (svenska) */
-$magicWords['sv'] = array(
-	'categorytree' => array( 0, 'kategoriträd', 'categorytree' ),
-);
+$magicWords['sv'] = [
+	'categorytree' => [ 0, 'kategoriträd', 'categorytree' ],
+];
 
 /** Turkish (Türkçe) */
-$magicWords['tr'] = array(
-	'categorytree' => array( 0, 'kategorihiyerarşisi', 'kategoriağacı', 'ulamhiyerarşisi', 'ulamağacı' ),
-);
+$magicWords['tr'] = [
+	'categorytree' => [ 0, 'kategorihiyerarşisi', 'kategoriağacı', 'ulamhiyerarşisi', 'ulamağacı' ],
+];
 
 /** Tatar (Cyrillic script) (татарча) */
-$magicWords['tt-cyrl'] = array(
-	'categorytree' => array( 0, 'төркемнәр_шәҗәрәсе' ),
-);
+$magicWords['tt-cyrl'] = [
+	'categorytree' => [ 0, 'төркемнәр_шәҗәрәсе' ],
+];
 
 /** Tuvinian (тыва дыл) */
-$magicWords['tyv'] = array(
-	'categorytree' => array( 0, 'аңгылал_ыяжы' ),
-);
+$magicWords['tyv'] = [
+	'categorytree' => [ 0, 'аңгылал_ыяжы' ],
+];
 
 /** Ukrainian (українська) */
-$magicWords['uk'] = array(
-	'categorytree' => array( 0, 'деревокатегорій' ),
-);
+$magicWords['uk'] = [
+	'categorytree' => [ 0, 'деревокатегорій' ],
+];
 
 /** Urdu (اردو) */
-$magicWords['ur'] = array(
-	'categorytree' => array( 0, 'شجر_زمرہ' ),
-);
+$magicWords['ur'] = [
+	'categorytree' => [ 0, 'شجر_زمرہ' ],
+];
 
 /** Uzbek (oʻzbekcha/ўзбекча) */
-$magicWords['uz'] = array(
-	'categorytree' => array( 0, 'turkumiyerarxiyasi', 'turkumdaraxti' ),
-);
+$magicWords['uz'] = [
+	'categorytree' => [ 0, 'turkumiyerarxiyasi', 'turkumdaraxti' ],
+];
 
 /** Vietnamese (Tiếng Việt) */
-$magicWords['vi'] = array(
-	'categorytree' => array( 0, 'cây_thể_loại', 'câythểloại' ),
-);
+$magicWords['vi'] = [
+	'categorytree' => [ 0, 'cây_thể_loại', 'câythểloại' ],
+];
 
 /** Yiddish (ייִדיש) */
-$magicWords['yi'] = array(
-	'categorytree' => array( 0, 'קאטעגאריע_בוים' ),
-);
+$magicWords['yi'] = [
+	'categorytree' => [ 0, 'קאטעגאריע_בוים' ],
+];
 
 /** Simplified Chinese (中文（简体）‎) */
-$magicWords['zh-hans'] = array(
-	'categorytree' => array( 0, '分类树' ),
-);
+$magicWords['zh-hans'] = [
+	'categorytree' => [ 0, '分类树' ],
+];
 
 /** Traditional Chinese (中文（繁體）‎) */
-$magicWords['zh-hant'] = array(
-	'categorytree' => array( 0, '分類樹' ),
-);
\ No newline at end of file
+$magicWords['zh-hant'] = [
+	'categorytree' => [ 0, '分類樹' ],
+];
diff --git a/CategoryTree.i18n.php b/CategoryTree.i18n.php
index d33f654b..aa51803b 100644
--- a/CategoryTree.i18n.php
+++ b/CategoryTree.i18n.php
@@ -10,10 +10,10 @@
  *
  * This shim maintains compatibility back to MediaWiki 1.17.
  */
-$messages = array();
+$messages = [];
 if ( !function_exists( 'wfJsonI18nShimed9738563f370e2c' ) ) {
 	function wfJsonI18nShimed9738563f370e2c( $cache, $code, &$cachedData ) {
-		$codeSequence = array_merge( array( $code ), $cachedData['fallbackSequence'] );
+		$codeSequence = array_merge( [ $code ], $cachedData['fallbackSequence'] );
 		foreach ( $codeSequence as $csCode ) {
 			$fileName = dirname( __FILE__ ) . "/i18n/$csCode.json";
 			if ( is_readable( $fileName ) ) {
diff --git a/CategoryTreeFunctions.php b/CategoryTreeFunctions.php
index 2f88dcc3..48c64108 100644
--- a/CategoryTreeFunctions.php
+++ b/CategoryTreeFunctions.php
@@ -11,7 +11,7 @@
  */
 
 class CategoryTree {
-	public $mOptions = array();
+	public $mOptions = [];
 
 	/**
 	 * @param $options array
@@ -81,7 +81,7 @@ class CategoryTree {
 			$nn = preg_split( '![\s#:|]+!', $nn );
 		}
 
-		$namespaces = array();
+		$namespaces = [];
 
 		foreach ( $nn as $n ) {
 			if ( is_int( $n ) ) {
@@ -334,7 +334,7 @@ class CategoryTree {
 		$html .= Html::openElement( 'div', $attr );
 
 		if ( !$allowMissing && !$title->getArticleID() ) {
-			$html .= Html::openElement( 'span', array( 'class' => 'CategoryTreeNotice' ) );
+			$html .= Html::openElement( 'span', [ 'class' => 'CategoryTreeNotice' ] );
 			if ( $parser ) {
 				$html .= $parser->recursiveTagParse( wfMessage( 'categorytree-not-found', $category )->plain() );
 			} else {
@@ -376,19 +376,19 @@ class CategoryTree {
 		$mode = $this->getOption( 'mode' );
 		$namespaces = $this->getOption( 'namespaces' );
 
-		$tables = array( 'page', 'categorylinks' );
-		$fields = array( 'page_id', 'page_namespace', 'page_title',
+		$tables = [ 'page', 'categorylinks' ];
+		$fields = [ 'page_id', 'page_namespace', 'page_title',
 			'page_is_redirect', 'page_len', 'page_latest', 'cl_to',
-			'cl_from' );
-		$where = array();
-		$joins = array();
-		$options = array( 'ORDER BY' => 'cl_type, cl_sortkey', 'LIMIT' => $wgCategoryTreeMaxChildren );
+			'cl_from' ];
+		$where = [];
+		$joins = [];
+		$options = [ 'ORDER BY' => 'cl_type, cl_sortkey', 'LIMIT' => $wgCategoryTreeMaxChildren ];
 
 		if ( $inverse ) {
-			$joins['categorylinks'] = array( 'RIGHT JOIN', array( 'cl_to = page_title', 'page_namespace' => NS_CATEGORY ) );
+			$joins['categorylinks'] = [ 'RIGHT JOIN', [ 'cl_to = page_title', 'page_namespace' => NS_CATEGORY ] ];
 			$where['cl_from'] = $title->getArticleID();
 		} else {
-			$joins['categorylinks'] = array( 'JOIN', 'cl_from = page_id' );
+			$joins['categorylinks'] = [ 'JOIN', 'cl_from = page_id' ];
 			$where['cl_to'] = $title->getDBkey();
 			$options['USE INDEX']['categorylinks'] = 'cl_sortkey';
 
@@ -398,7 +398,7 @@ class CategoryTree {
 				$where['page_namespace'] = $namespaces;
 			} elseif ( $mode != CategoryTreeMode::ALL ) {
 				if ( $mode == CategoryTreeMode::PAGES ) {
-					$where['cl_type'] = array( 'page', 'subcat' );
+					$where['cl_type'] = [ 'page', 'subcat' ];
 				} else {
 					$where['cl_type'] = 'subcat';
 				}
@@ -409,9 +409,9 @@ class CategoryTree {
 		$doCount = !$inverse && $wgCategoryTreeUseCategoryTable;
 
 		if ( $doCount ) {
-			$tables = array_merge( $tables, array( 'category' ) );
-			$fields = array_merge( $fields, array( 'cat_id', 'cat_title', 'cat_subcats', 'cat_pages', 'cat_files' ) );
-			$joins['category'] = array( 'LEFT JOIN', array( 'cat_title = page_title', 'page_namespace' => NS_CATEGORY ) );
+			$tables = array_merge( $tables, [ 'category' ] );
+			$fields = array_merge( $fields, [ 'cat_id', 'cat_title', 'cat_subcats', 'cat_pages', 'cat_files' ] );
+			$joins['category'] = [ 'LEFT JOIN', [ 'cat_title = page_title', 'page_namespace' => NS_CATEGORY ] ];
 		}
 
 		$res = $dbr->select( $tables, $fields, $where, __METHOD__, $options, $joins );
@@ -461,16 +461,16 @@ class CategoryTree {
 
 		$res = $dbr->select(
 			'categorylinks',
-			array(
+			[
 				'page_namespace' => NS_CATEGORY,
 				'page_title' => 'cl_to',
-			),
-			array( 'cl_from' => $title->getArticleID() ),
+			],
+			[ 'cl_from' => $title->getArticleID() ],
 			__METHOD__,
-			array(
+			[
 				'LIMIT' => $wgCategoryTreeMaxChildren,
 				'ORDER BY' => 'cl_to'
-			)
+			]
 		);
 
 		$special = SpecialPage::getTitleFor( 'CategoryTree' );
@@ -489,8 +489,8 @@ class CategoryTree {
 				$s .= wfMessage( 'pipe-separator' )->escaped();
 			}
 
-			$s .= Xml::openElement( 'span', array( 'class' => 'CategoryTreeItem' ) );
-			$s .= Xml::openElement( 'a', array( 'class' => 'CategoryTreeLabel', 'href' => $wikiLink ) )
+			$s .= Xml::openElement( 'span', [ 'class' => 'CategoryTreeItem' ] );
+			$s .= Xml::openElement( 'a', [ 'class' => 'CategoryTreeLabel', 'href' => $wikiLink ] )
 				. $label . Xml::closeElement( 'a' );
 			$s .= Xml::closeElement( 'span' );
 
@@ -578,10 +578,10 @@ class CategoryTree {
 		#      Specifically, the CategoryTreeChildren div must be the first
 		#      sibling with nodeName = DIV of the grandparent of the expland link.
 
-		$s .= Xml::openElement( 'div', array( 'class' => 'CategoryTreeSection' ) );
-		$s .= Xml::openElement( 'div', array( 'class' => 'CategoryTreeItem' ) );
+		$s .= Xml::openElement( 'div', [ 'class' => 'CategoryTreeSection' ] );
+		$s .= Xml::openElement( 'div', [ 'class' => 'CategoryTreeItem' ] );
 
-		$attr = array( 'class' => 'CategoryTreeBullet' );
+		$attr = [ 'class' => 'CategoryTreeBullet' ];
 
 		# Get counts, with conversion to integer so === works
 		# Note: $allCount is the total number of cat members,
@@ -605,7 +605,7 @@ class CategoryTree {
 				$bullet = wfMessage( 'categorytree-empty-bullet' )->plain() . ' ';
 				$attr['class'] = 'CategoryTreeEmptyBullet';
 			} else {
-				$linkattr = array( );
+				$linkattr = [];
 
 				$linkattr[ 'class' ] = "CategoryTreeToggle";
 				$linkattr['style'] = 'display: none;'; // Unhidden by JS
@@ -630,23 +630,23 @@ class CategoryTree {
 		}
 		$s .= Xml::tags( 'span', $attr, $bullet ) . ' ';
 
-		$s .= Xml::openElement( 'a', array( 'class' => $labelClass, 'href' => $wikiLink ) )
+		$s .= Xml::openElement( 'a', [ 'class' => $labelClass, 'href' => $wikiLink ] )
 			. $label . Xml::closeElement( 'a' );
 
 		if ( $count !== false && $this->getOption( 'showcount' ) ) {
 			$pages = $allCount - $subcatCount - $fileCount;
 
 			global $wgContLang, $wgLang;
-			$attr = array(
+			$attr = [
 				'title' => wfMessage( 'categorytree-member-counts' )
 					->numParams( $subcatCount, $pages , $fileCount, $allCount, $count )->text(),
 				'dir' => $wgLang->getDir() # numbers and commas get messed up in a mixed dir env
-			);
+			];
 
 			$s .= $wgContLang->getDirMark() . ' ';
 
 			# Create a list of category members with only non-zero member counts
-			$memberNums = array();
+			$memberNums = [];
 			if ( $subcatCount ) {
 				$memberNums[] = wfMessage( 'categorytree-num-categories' )
 					->numParams( $subcatCount )->text();
@@ -678,16 +678,16 @@ class CategoryTree {
 		$s .= "\n\t\t";
 		$s .= Xml::openElement(
 			'div',
-			array(
+			[
 				'class' => 'CategoryTreeChildren',
 				'style' => $children > 0 ? "display:block" : "display:none"
-			)
+			]
 		);
 
 		if ( $ns == NS_CATEGORY && $children > 0 ) {
 			$children = $this->renderChildren( $title, $children );
 			if ( $children == '' ) {
-				$s .= Xml::openElement( 'i', array( 'class' => 'CategoryTreeNotice' ) );
+				$s .= Xml::openElement( 'i', [ 'class' => 'CategoryTreeNotice' ] );
 				if ( $mode == CategoryTreeMode::CATEGORIES ) {
 					$s .= wfMessage( 'categorytree-no-subcategories' )->text();
 				} elseif ( $mode == CategoryTreeMode::PAGES ) {
diff --git a/CategoryTreePage.php b/CategoryTreePage.php
index a8be4234..c9436b22 100644
--- a/CategoryTreePage.php
+++ b/CategoryTreePage.php
@@ -58,7 +58,7 @@ class CategoryTreePage extends SpecialPage {
 			$this->target = null;
 		}
 
-		$options = array();
+		$options = [];
 
 		# grab all known options from the request. Normalization is done by the CategoryTree class
 		foreach ( $wgCategoryTreeDefaultOptions as $option => $default ) {
@@ -84,7 +84,7 @@ class CategoryTreePage extends SpecialPage {
 			$title = CategoryTree::makeTitle( $this->target );
 
 			if ( $title && $title->getArticleID() ) {
-				$output->addHTML( Xml::openElement( 'div', array( 'class' => 'CategoryTreeParents' ) ) );
+				$output->addHTML( Xml::openElement( 'div', [ 'class' => 'CategoryTreeParents' ] ) );
 				$output->addHTML( $this->msg( 'categorytree-parents' )->parse() );
 				$output->addHTML( $this->msg( 'colon-separator' )->escaped() );
 
@@ -98,11 +98,11 @@ class CategoryTreePage extends SpecialPage {
 
 				$output->addHTML( Xml::closeElement( 'div' ) );
 
-				$output->addHTML( Xml::openElement( 'div', array( 'class' => 'CategoryTreeResult' ) ) );
+				$output->addHTML( Xml::openElement( 'div', [ 'class' => 'CategoryTreeResult' ] ) );
 				$output->addHTML( $this->tree->renderNode( $title, 1 ) );
 				$output->addHTML( Xml::closeElement( 'div' ) );
 			} else {
-				$output->addHTML( Xml::openElement( 'div', array( 'class' => 'CategoryTreeNotice' ) ) );
+				$output->addHTML( Xml::openElement( 'div', [ 'class' => 'CategoryTreeNotice' ] ) );
 				$output->addHTML( $this->msg( 'categorytree-not-found', $this->target )->parse() );
 				$output->addHTML( Xml::closeElement( 'div' ) );
 			}
@@ -178,11 +178,11 @@ class CategoryTreePage extends SpecialPage {
 		}
 		if ( !$title ) {
 			// No prefix suggestion outside of category namespace
-			return array();
+			return [];
 		}
 		// Autocomplete subpage the same as a normal search, but just for categories
 		$prefixSearcher = new TitlePrefixSearch;
-		$result = $prefixSearcher->search( $title->getPrefixedText(), $limit, array( NS_CATEGORY ), $offset );
+		$result = $prefixSearcher->search( $title->getPrefixedText(), $limit, [ NS_CATEGORY ], $offset );
 
 		return array_map( function ( Title $t ) {
 			// Remove namespace in search suggestion