From 46b9ba1e48028e5d9924d23f915c2517c856f5a5 Mon Sep 17 00:00:00 2001
From: Luca Tumedei <luca.tumedei@automattic.com>
Date: Wed, 12 Aug 2026 16:33:54 +0200
Subject: [PATCH 1/2] Build/Test Tools: Increase shared user fixtures following
 switch to bcrypt hashing.

Merges [60253] to the 6.8 branch.

User creation is more expensive on 6.8 since the switch to bcrypt hashing, and users created in wpSetUpBeforeClass fixtures hash at PHP's full default cost. Moving per-test user creation into shared fixtures cuts how many of those hashes the suite performs.

Props peterwilsoncc, johnbillion.
See #63026.
---
 tests/phpunit/tests/admin/includesPlugin.php  |  21 +++-
 .../phpunit/tests/admin/includesTemplate.php  |  14 ++-
 .../ajax/wpAjaxSendAttachmentToEditor.php     |  38 +++---
 .../tests/ajax/wpCustomizeNavMenus.php        |  37 +++++-
 tests/phpunit/tests/auth.php                  |  11 +-
 .../comment/wpHandleCommentSubmission.php     |  39 +++---
 tests/phpunit/tests/customize/control.php     |  18 ++-
 .../tests/customize/custom-css-setting.php    |  32 +++--
 tests/phpunit/tests/customize/manager.php     |  24 ++--
 .../tests/customize/nav-menu-item-setting.php |  18 ++-
 .../tests/customize/nav-menu-setting.php      |  18 ++-
 tests/phpunit/tests/customize/nav-menus.php   |  20 ++-
 tests/phpunit/tests/customize/panel.php       |  25 +++-
 .../customize/selective-refresh-ajax.php      |  26 +++-
 tests/phpunit/tests/customize/setting.php     |  32 +++--
 tests/phpunit/tests/customize/widgets.php     |  19 ++-
 tests/phpunit/tests/general/template.php      |  38 ++++--
 tests/phpunit/tests/l10n.php                  |  17 ++-
 tests/phpunit/tests/l10n/getUserLocale.php    |  53 +++++---
 tests/phpunit/tests/meta.php                  | 115 +++++++++---------
 tests/phpunit/tests/oembed/controller.php     |  24 +---
 tests/phpunit/tests/oembed/wpOembed.php       |  26 +++-
 tests/phpunit/tests/post/getPages.php         |  71 ++++++-----
 .../tests/post/getPostsByAuthorSql.php        |  36 +++++-
 tests/phpunit/tests/query/conditionals.php    |  40 +++---
 tests/phpunit/tests/taxonomy.php              |  16 ++-
 tests/phpunit/tests/url.php                   |  17 ++-
 tests/phpunit/tests/user.php                  |  14 +--
 28 files changed, 575 insertions(+), 284 deletions(-)

diff --git a/tests/phpunit/tests/admin/includesPlugin.php b/tests/phpunit/tests/admin/includesPlugin.php
index e95697810d43f..4d47fb7db0a81 100644
--- a/tests/phpunit/tests/admin/includesPlugin.php
+++ b/tests/phpunit/tests/admin/includesPlugin.php
@@ -4,7 +4,16 @@
  * @group admin
  */
 class Tests_Admin_IncludesPlugin extends WP_UnitTestCase {
+
+	/**
+	 * Admin user ID.
+	 *
+	 * @var int $admin_id
+	 */
+	public static $admin_id;
+
 	public static function wpSetUpBeforeClass( $factory ) {
+		self::$admin_id = $factory->user->create( array( 'role' => 'administrator' ) );
 		self::_back_up_mu_plugins();
 	}
 
@@ -37,7 +46,7 @@ public function test_get_plugin_data() {
 
 	public function test_menu_page_url() {
 		$current_user = get_current_user_id();
-		wp_set_current_user( self::factory()->user->create( array( 'role' => 'administrator' ) ) );
+		wp_set_current_user( self::$admin_id );
 		update_option( 'siteurl', 'http://example.com' );
 
 		// Add some pages.
@@ -81,7 +90,7 @@ public function test_submenu_position( $position, $expected_position ) {
 		global $submenu;
 		global $menu;
 		$current_user = get_current_user_id();
-		$admin_user   = self::factory()->user->create( array( 'role' => 'administrator' ) );
+		$admin_user   = self::$admin_id;
 		wp_set_current_user( $admin_user );
 		set_current_screen( 'dashboard' );
 
@@ -134,7 +143,7 @@ public function test_submenu_helpers_position( $position, $expected_position ) {
 		$menu    = array();
 
 		$current_user = get_current_user_id();
-		$admin_user   = self::factory()->user->create( array( 'role' => 'administrator' ) );
+		$admin_user   = self::$admin_id;
 		wp_set_current_user( $admin_user );
 		set_current_screen( 'dashboard' );
 
@@ -283,7 +292,7 @@ public function test_position_when_parent_slug_child_slug_are_the_same() {
 		$submenu      = array();
 		$menu         = array();
 		$current_user = get_current_user_id();
-		$admin_user   = self::factory()->user->create( array( 'role' => 'administrator' ) );
+		$admin_user   = self::$admin_id;
 		wp_set_current_user( $admin_user );
 		set_current_screen( 'dashboard' );
 
@@ -316,7 +325,7 @@ public function test_passing_string_as_position_fires_doing_it_wrong_submenu() {
 		$submenu      = array();
 		$menu         = array();
 		$current_user = get_current_user_id();
-		$admin_user   = self::factory()->user->create( array( 'role' => 'administrator' ) );
+		$admin_user   = self::$admin_id;
 		wp_set_current_user( $admin_user );
 		set_current_screen( 'dashboard' );
 
@@ -344,7 +353,7 @@ public function test_passing_float_as_position_does_not_override_int() {
 		$submenu      = array();
 		$menu         = array();
 		$current_user = get_current_user_id();
-		$admin_user   = self::factory()->user->create( array( 'role' => 'administrator' ) );
+		$admin_user   = self::$admin_id;
 		wp_set_current_user( $admin_user );
 		set_current_screen( 'dashboard' );
 
diff --git a/tests/phpunit/tests/admin/includesTemplate.php b/tests/phpunit/tests/admin/includesTemplate.php
index 66e3befd5f07b..909aff217a583 100644
--- a/tests/phpunit/tests/admin/includesTemplate.php
+++ b/tests/phpunit/tests/admin/includesTemplate.php
@@ -3,6 +3,16 @@
  * @group admin
  */
 class Tests_Admin_IncludesTemplate extends WP_UnitTestCase {
+	/**
+	 * Editor user ID.
+	 *
+	 * @var int $editor_id
+	 */
+	public static $editor_id;
+
+	public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
+		self::$editor_id = $factory->user->create( array( 'role' => 'editor' ) );
+	}
 
 	/**
 	 * @ticket 51137
@@ -64,7 +74,7 @@ public function test_get_inline_data_contains_term_if_show_ui_is_false_but_show_
 		wp_set_object_terms( $post->ID, $term['term_id'], 'wptests_tax_1' );
 
 		// Test that get_inline_data() has `post_category` div containing the assigned term.
-		wp_set_current_user( self::factory()->user->create( array( 'role' => 'editor' ) ) );
+		wp_set_current_user( self::$editor_id );
 		get_inline_data( $post );
 		$this->expectOutputRegex( '/<div class="post_category" id="wptests_tax_1_' . $post->ID . '">' . $term['term_id'] . '<\/div>/' );
 	}
@@ -90,7 +100,7 @@ public function test_get_inline_data_contains_term_if_show_ui_is_false_but_show_
 		wp_set_object_terms( $post->ID, $term['term_id'], 'wptests_tax_1' );
 
 		// Test that get_inline_data() has `tags_input` div containing the assigned term.
-		wp_set_current_user( self::factory()->user->create( array( 'role' => 'editor' ) ) );
+		wp_set_current_user( self::$editor_id );
 		get_inline_data( $post );
 		$this->expectOutputRegex( '/<div class="tags_input" id="wptests_tax_1_' . $post->ID . '">Test<\/div>/' );
 	}
diff --git a/tests/phpunit/tests/ajax/wpAjaxSendAttachmentToEditor.php b/tests/phpunit/tests/ajax/wpAjaxSendAttachmentToEditor.php
index 29066ff2877f9..351485afd11a4 100644
--- a/tests/phpunit/tests/ajax/wpAjaxSendAttachmentToEditor.php
+++ b/tests/phpunit/tests/ajax/wpAjaxSendAttachmentToEditor.php
@@ -13,6 +13,28 @@
  */
 class Tests_Ajax_wpAjaxSendAttachmentToEditor extends WP_Ajax_UnitTestCase {
 
+	/**
+	 * Shared user ID for the tests.
+	 *
+	 * @var int
+	 */
+	public static $user_id = 0;
+
+	/**
+	 * Set up shared fixtures.
+	 *
+	 * @param WP_UnitTest_Factory $factory
+	 */
+	public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
+		self::$user_id = $factory->user->create(
+			array(
+				'role'       => 'administrator',
+				'user_login' => 'user_36578_administrator',
+				'user_email' => 'user_36578_administrator@example.com',
+			)
+		);
+	}
+
 	/**
 	 * @ticket 36578
 	 *
@@ -105,13 +127,7 @@ public function test_wp_ajax_send_attachment_to_editor_should_return_a_link() {
 	public function test_wp_ajax_set_attachment_thumbnail_success() {
 		// Become an administrator.
 		$post    = $_POST;
-		$user_id = self::factory()->user->create(
-			array(
-				'role'       => 'administrator',
-				'user_login' => 'user_36578_administrator',
-				'user_email' => 'user_36578_administrator@example.com',
-			)
-		);
+		$user_id = self::$user_id;
 		wp_set_current_user( $user_id );
 		$_POST = array_merge( $_POST, $post );
 
@@ -151,13 +167,7 @@ public function test_wp_ajax_set_attachment_thumbnail_success() {
 	public function test_wp_ajax_set_attachment_thumbnail_missing_nonce() {
 		// Become an administrator.
 		$post    = $_POST;
-		$user_id = self::factory()->user->create(
-			array(
-				'role'       => 'administrator',
-				'user_login' => 'user_36578_administrator',
-				'user_email' => 'user_36578_administrator@example.com',
-			)
-		);
+		$user_id = self::$user_id;
 		wp_set_current_user( $user_id );
 		$_POST = array_merge( $_POST, $post );
 
diff --git a/tests/phpunit/tests/ajax/wpCustomizeNavMenus.php b/tests/phpunit/tests/ajax/wpCustomizeNavMenus.php
index 1dfe5f684d01e..08353f6e65524 100644
--- a/tests/phpunit/tests/ajax/wpCustomizeNavMenus.php
+++ b/tests/phpunit/tests/ajax/wpCustomizeNavMenus.php
@@ -38,6 +38,26 @@ class Tests_Ajax_wpCustomizeNavMenus extends WP_Ajax_UnitTestCase {
 	 */
 	public static $terms;
 
+
+	/**
+	 * Admin user ID.
+	 *
+	 * @var int
+	 */
+	public static $admin_user_id = 0;
+
+	/**
+	 * User IDs keyed by role.
+	 *
+	 * @var int[]
+	 */
+	public static $user_ids = array();
+
+	/**
+	 * Set up shared fixtures.
+	 *
+	 * @param WP_UnitTest_Factory $factory The factory.
+	 */
 	public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
 		// Make some post objects.
 		self::$posts = $factory->post->create_many( 5 );
@@ -45,6 +65,13 @@ public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
 
 		// Some terms too.
 		self::$terms = $factory->term->create_many( 5 );
+
+		// Create an admin user.
+		self::$admin_user_id = $factory->user->create( array( 'role' => 'administrator' ) );
+
+		foreach ( array( 'administrator', 'editor', 'author', 'contributor', 'subscriber' ) as $role ) {
+			self::$user_ids[ $role ] = $factory->user->create( array( 'role' => $role ) );
+		}
 	}
 
 	/**
@@ -53,7 +80,7 @@ public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
 	public function set_up() {
 		parent::set_up();
 		require_once ABSPATH . WPINC . '/class-wp-customize-manager.php';
-		wp_set_current_user( self::factory()->user->create( array( 'role' => 'administrator' ) ) );
+		wp_set_current_user( self::$admin_user_id );
 		global $wp_customize;
 		$this->wp_customize = new WP_Customize_Manager();
 		$wp_customize       = $this->wp_customize;
@@ -91,7 +118,7 @@ public function test_ajax_load_available_items_cap_check( $role, $expected_resul
 			$this->expectExceptionMessage( '-1' );
 		}
 
-		wp_set_current_user( self::factory()->user->create( array( 'role' => $role ) ) );
+		wp_set_current_user( self::$user_ids[ $role ] );
 
 		$_POST = array(
 			'action'                => 'load-available-menu-items-customizer',
@@ -485,7 +512,7 @@ public function test_ajax_search_available_items_caps_check( $role, $expected_re
 			$this->expectExceptionMessage( '-1' );
 		}
 
-		wp_set_current_user( self::factory()->user->create( array( 'role' => $role ) ) );
+		wp_set_current_user( self::$user_ids[ $role ] );
 
 		$_POST = array(
 			'action'                => 'search-available-menu-items-customizer',
@@ -705,7 +732,7 @@ public function test_ajax_insert_auto_draft_failures() {
 		$this->assertSame( 'bad_nonce', $response['data'] );
 
 		// Bad nonce.
-		wp_set_current_user( self::factory()->user->create( array( 'role' => 'subscriber' ) ) );
+		wp_set_current_user( self::$user_ids['subscriber'] );
 		$_POST                = wp_slash(
 			array(
 				'customize-menus-nonce' => wp_create_nonce( 'customize-menus' ),
@@ -718,7 +745,7 @@ public function test_ajax_insert_auto_draft_failures() {
 		$this->assertSame( 'customize_not_allowed', $response['data'] );
 
 		// Missing params.
-		wp_set_current_user( self::factory()->user->create( array( 'role' => 'administrator' ) ) );
+		wp_set_current_user( self::$user_ids['administrator'] );
 		$_POST                = wp_slash(
 			array(
 				'customize-menus-nonce' => wp_create_nonce( 'customize-menus' ),
diff --git a/tests/phpunit/tests/auth.php b/tests/phpunit/tests/auth.php
index 3bdcb98b65ddd..405a8526d05df 100644
--- a/tests/phpunit/tests/auth.php
+++ b/tests/phpunit/tests/auth.php
@@ -1579,12 +1579,7 @@ public function test_wp_signon_does_not_throw_fatal_errors_with_array_parameters
 	 * @covers ::wp_validate_application_password
 	 */
 	public function test_application_password_authentication() {
-		$user_id = self::factory()->user->create(
-			array(
-				'user_login' => 'http_auth_login',
-				'user_pass'  => 'http_auth_pass', // Shouldn't be allowed for API login.
-			)
-		);
+		$user_id = self::$_user->ID;
 
 		// Create a new app-only password.
 		list( $user_app_password, $item ) = WP_Application_Passwords::create_new_application_password( $user_id, array( 'name' => 'phpunit' ) );
@@ -1594,8 +1589,8 @@ public function test_application_password_authentication() {
 		add_filter( 'wp_is_application_passwords_available', '__return_true' );
 
 		// Fake an HTTP Auth request with the regular account password first.
-		$_SERVER['PHP_AUTH_USER'] = 'http_auth_login';
-		$_SERVER['PHP_AUTH_PW']   = 'http_auth_pass';
+		$_SERVER['PHP_AUTH_USER'] = self::USER_LOGIN;
+		$_SERVER['PHP_AUTH_PW']   = self::USER_PASS;
 
 		$this->assertNull(
 			wp_validate_application_password( null ),
diff --git a/tests/phpunit/tests/comment/wpHandleCommentSubmission.php b/tests/phpunit/tests/comment/wpHandleCommentSubmission.php
index 49d54e3da52cd..3f2ba84194a0d 100644
--- a/tests/phpunit/tests/comment/wpHandleCommentSubmission.php
+++ b/tests/phpunit/tests/comment/wpHandleCommentSubmission.php
@@ -9,6 +9,7 @@ class Tests_Comment_wpHandleCommentSubmission extends WP_UnitTestCase {
 
 	protected static $post;
 	protected static $author_id;
+	protected static $author_id2;
 	protected static $editor_id;
 
 	protected $preprocess_comment_data = array();
@@ -22,6 +23,13 @@ public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
 			)
 		);
 
+		self::$author_id2 = $factory->user->create(
+			array(
+				'role'     => 'author',
+				'user_url' => 'http://user.example.org',
+			)
+		);
+
 		self::$editor_id = $factory->user->create(
 			array(
 				'role' => 'editor',
@@ -223,11 +231,7 @@ public function test_submitting_comment_to_password_protected_post_succeeds() {
 
 	public function test_submitting_valid_comment_as_logged_in_user_succeeds() {
 
-		$user = self::factory()->user->create_and_get(
-			array(
-				'user_url' => 'http://user.example.org',
-			)
-		);
+		$user = get_user_by( 'id', self::$author_id2 );
 
 		wp_set_current_user( $user->ID );
 
@@ -314,11 +318,7 @@ public function test_submitting_comment_as_logged_in_user_to_inaccessible_privat
 
 		$error = 'comment_id_not_found';
 
-		$user = self::factory()->user->create_and_get(
-			array(
-				'role' => 'author',
-			)
-		);
+		$user = get_user_by( 'id', self::$author_id2 );
 
 		wp_set_current_user( $user->ID );
 
@@ -343,11 +343,7 @@ public function test_submitting_comment_to_private_post_with_closed_comments_ret
 
 		$error = 'comment_id_not_found';
 
-		$user = self::factory()->user->create_and_get(
-			array(
-				'role' => 'author',
-			)
-		);
+		$user = get_user_by( 'id', self::$author_id2 );
 
 		wp_set_current_user( $user->ID );
 
@@ -834,12 +830,8 @@ public function test_comments_flood() {
 	/**
 	 * @ticket 36901
 	 */
-	public function test_comments_flood_user_is_admin() {
-		$user = self::factory()->user->create_and_get(
-			array(
-				'role' => 'administrator',
-			)
-		);
+	public function test_comments_flood_user_can_moderate_comments() {
+		$user = get_user_by( 'id', self::$editor_id );
 		wp_set_current_user( $user->ID );
 
 		$data          = array(
@@ -853,8 +845,9 @@ public function test_comments_flood_user_is_admin() {
 		$data['comment'] = 'Wow! I am quick!';
 		$second_comment  = wp_handle_comment_submission( $data );
 
-		$this->assertNotWPError( $second_comment );
-		$this->assertSame( (string) self::$post->ID, $second_comment->comment_post_ID );
+		$this->assertTrue( current_user_can( 'moderate_comments' ), 'Test user should have the moderate_comments capability' );
+		$this->assertNotWPError( $second_comment, 'Second comment should not trigger comment flooding error.' );
+		$this->assertSame( (string) self::$post->ID, $second_comment->comment_post_ID, 'Second comment should be made against initial post.' );
 	}
 
 	/**
diff --git a/tests/phpunit/tests/customize/control.php b/tests/phpunit/tests/customize/control.php
index d472eacad920a..ea3311e15c192 100644
--- a/tests/phpunit/tests/customize/control.php
+++ b/tests/phpunit/tests/customize/control.php
@@ -17,12 +17,28 @@ class Test_WP_Customize_Control extends WP_UnitTestCase {
 	 */
 	public $wp_customize;
 
+	/**
+	 * Shared user ID for the tests.
+
+	 * @var int
+	 */
+	public static $user_id = 0;
+
+	/**
+	 * Set up shared fixtures.
+	 *
+	 * @param WP_UnitTest_Factory $factory Factory.
+	 */
+	public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
+		self::$user_id = $factory->user->create( array( 'role' => 'administrator' ) );
+	}
+
 	/**
 	 * Set up.
 	 */
 	public function set_up() {
 		parent::set_up();
-		wp_set_current_user( self::factory()->user->create( array( 'role' => 'administrator' ) ) );
+		wp_set_current_user( self::$user_id );
 		require_once ABSPATH . WPINC . '/class-wp-customize-manager.php';
 		$GLOBALS['wp_customize'] = new WP_Customize_Manager();
 		$this->wp_customize      = $GLOBALS['wp_customize'];
diff --git a/tests/phpunit/tests/customize/custom-css-setting.php b/tests/phpunit/tests/customize/custom-css-setting.php
index 015b6308af306..65cc3f717fe59 100644
--- a/tests/phpunit/tests/customize/custom-css-setting.php
+++ b/tests/phpunit/tests/customize/custom-css-setting.php
@@ -23,24 +23,40 @@ class Test_WP_Customize_Custom_CSS_Setting extends WP_UnitTestCase {
 	public $setting;
 
 	/**
-	 * Set up the test case.
+	 * The user ID to use for the tests.
 	 *
-	 * @see WP_UnitTestCase_Base::set_up()
+	 * @var int
 	 */
-	public function set_up() {
-		parent::set_up();
-		require_once ABSPATH . WPINC . '/class-wp-customize-manager.php';
+	public static $user_id = 0;
 
-		$user_id = self::factory()->user->create(
+	/**
+	 * Set up the test case.
+	 *
+	 * @see WP_UnitTestCase::set_up()
+	 */
+	public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
+		// Create a user to use for the tests.
+		self::$user_id = $factory->user->create(
 			array(
 				'role' => 'administrator',
 			)
 		);
+
 		if ( is_multisite() ) {
-			grant_super_admin( $user_id );
+			grant_super_admin( self::$user_id );
 		}
+	}
+
+	/**
+	 * Set up the test case.
+	 *
+	 * @see WP_UnitTestCase_Base::set_up()
+	 */
+	public function set_up() {
+		parent::set_up();
+		require_once ABSPATH . WPINC . '/class-wp-customize-manager.php';
 
-		wp_set_current_user( $user_id );
+		wp_set_current_user( self::$user_id );
 
 		global $wp_customize;
 		$this->wp_customize = new WP_Customize_Manager();
diff --git a/tests/phpunit/tests/customize/manager.php b/tests/phpunit/tests/customize/manager.php
index 0f8ddb2d9bbf3..21bdd85eebac3 100644
--- a/tests/phpunit/tests/customize/manager.php
+++ b/tests/phpunit/tests/customize/manager.php
@@ -26,6 +26,13 @@ class Tests_WP_Customize_Manager extends WP_UnitTestCase {
 	 */
 	protected static $admin_user_id;
 
+	/**
+	 * Second admin user ID.
+	 *
+	 * @var int
+	 */
+	protected static $other_admin_user_id;
+
 	/**
 	 * Subscriber user ID.
 	 *
@@ -46,8 +53,9 @@ class Tests_WP_Customize_Manager extends WP_UnitTestCase {
 	 * @param WP_UnitTest_Factory $factory Factory.
 	 */
 	public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
-		self::$subscriber_user_id = $factory->user->create( array( 'role' => 'subscriber' ) );
-		self::$admin_user_id      = $factory->user->create( array( 'role' => 'administrator' ) );
+		self::$subscriber_user_id  = $factory->user->create( array( 'role' => 'subscriber' ) );
+		self::$admin_user_id       = $factory->user->create( array( 'role' => 'administrator' ) );
+		self::$other_admin_user_id = $factory->user->create( array( 'role' => 'administrator' ) );
 	}
 
 	/**
@@ -153,7 +161,7 @@ public function test_constructor() {
 	 */
 	public function test_constructor_deferred_changeset_uuid() {
 		wp_set_current_user( self::$admin_user_id );
-		$other_admin_user_id = self::factory()->user->create( array( 'role' => 'admin' ) );
+		$other_admin_user_id = self::$other_admin_user_id;
 
 		$data = array(
 			'blogname' => array(
@@ -1254,7 +1262,7 @@ public function test_save_changeset_post_without_theme_activation() {
 	 */
 	public function test_save_changeset_post_without_kses_corrupting_json() {
 		global $wp_customize;
-		$lesser_admin_user_id = self::factory()->user->create( array( 'role' => 'administrator' ) );
+		$lesser_admin_user_id = self::$other_admin_user_id;
 
 		$uuid         = wp_generate_uuid4();
 		$wp_customize = new WP_Customize_Manager(
@@ -1499,7 +1507,7 @@ public function test_save_changeset_post_with_varying_users() {
 
 		add_theme_support( 'custom-background' );
 		wp_set_current_user( self::$admin_user_id );
-		$other_admin_user_id = self::factory()->user->create( array( 'role' => 'administrator' ) );
+		$other_admin_user_id = self::$other_admin_user_id;
 
 		$uuid         = wp_generate_uuid4();
 		$wp_customize = $this->create_test_manager( $uuid );
@@ -1714,7 +1722,7 @@ public function test_save_changeset_post_with_unchanged_values() {
 
 		add_theme_support( 'custom-background' );
 		wp_set_current_user( self::$admin_user_id );
-		$other_admin_user_id = self::factory()->user->create( array( 'role' => 'administrator' ) );
+		$other_admin_user_id = self::$other_admin_user_id;
 
 		$uuid         = wp_generate_uuid4();
 		$wp_customize = $this->create_test_manager( $uuid );
@@ -1877,7 +1885,7 @@ public function test_save_changeset_post_with_autosave() {
 		$r = $wp_customize->save_changeset_post(
 			array(
 				'autosave' => true,
-				'user_id'  => self::factory()->user->create( array( 'role' => 'administrator' ) ),
+				'user_id'  => self::$other_admin_user_id,
 			)
 		);
 		$this->assertSame( 'illegal_autosave_with_non_current_user', $r->get_error_code() );
@@ -3009,7 +3017,7 @@ public function test_preview_url() {
 	 * @see WP_Customize_Manager::set_return_url()
 	 */
 	public function test_return_url() {
-		wp_set_current_user( self::factory()->user->create( array( 'role' => 'author' ) ) );
+		wp_set_current_user( self::$subscriber_user_id );
 		$this->assertSame( home_url( '/' ), $this->manager->get_return_url() );
 
 		wp_set_current_user( self::$admin_user_id );
diff --git a/tests/phpunit/tests/customize/nav-menu-item-setting.php b/tests/phpunit/tests/customize/nav-menu-item-setting.php
index 3f8efffd7069a..85cf0f10f7b5b 100644
--- a/tests/phpunit/tests/customize/nav-menu-item-setting.php
+++ b/tests/phpunit/tests/customize/nav-menu-item-setting.php
@@ -13,6 +13,22 @@ class Test_WP_Customize_Nav_Menu_Item_Setting extends WP_UnitTestCase {
 	 */
 	public $wp_customize;
 
+	/**
+	 * ID of the administrator user.
+	 *
+	 * @var int
+	 */
+	public static $administrator_id;
+
+	/**
+	 * Set up the shared fixture.
+	 *
+	 * @param WP_UnitTest_Factory $factory Factory instance.
+	 */
+	public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
+		self::$administrator_id = $factory->user->create( array( 'role' => 'administrator' ) );
+	}
+
 	/**
 	 * Set up a test case.
 	 *
@@ -21,7 +37,7 @@ class Test_WP_Customize_Nav_Menu_Item_Setting extends WP_UnitTestCase {
 	public function set_up() {
 		parent::set_up();
 		require_once ABSPATH . WPINC . '/class-wp-customize-manager.php';
-		wp_set_current_user( self::factory()->user->create( array( 'role' => 'administrator' ) ) );
+		wp_set_current_user( self::$administrator_id );
 
 		global $wp_customize;
 		$this->wp_customize = new WP_Customize_Manager();
diff --git a/tests/phpunit/tests/customize/nav-menu-setting.php b/tests/phpunit/tests/customize/nav-menu-setting.php
index 6d50c96ee0c62..1348c86395a92 100644
--- a/tests/phpunit/tests/customize/nav-menu-setting.php
+++ b/tests/phpunit/tests/customize/nav-menu-setting.php
@@ -14,6 +14,22 @@ class Test_WP_Customize_Nav_Menu_Setting extends WP_UnitTestCase {
 	 */
 	public $wp_customize;
 
+	/**
+	 * ID of the administrator user.
+	 *
+	 * @var int
+	 */
+	public static $administrator_id;
+
+	/**
+	 * Set up the shared fixture.
+	 *
+	 * @param WP_UnitTest_Factory $factory Factory instance.
+	 */
+	public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
+		self::$administrator_id = $factory->user->create( array( 'role' => 'administrator' ) );
+	}
+
 	/**
 	 * Set up a test case.
 	 *
@@ -22,7 +38,7 @@ class Test_WP_Customize_Nav_Menu_Setting extends WP_UnitTestCase {
 	public function set_up() {
 		parent::set_up();
 		require_once ABSPATH . WPINC . '/class-wp-customize-manager.php';
-		wp_set_current_user( self::factory()->user->create( array( 'role' => 'administrator' ) ) );
+		wp_set_current_user( self::$administrator_id );
 
 		global $wp_customize;
 		$this->wp_customize = new WP_Customize_Manager();
diff --git a/tests/phpunit/tests/customize/nav-menus.php b/tests/phpunit/tests/customize/nav-menus.php
index 58f5c75db5d8a..e2dc96e37e50e 100644
--- a/tests/phpunit/tests/customize/nav-menus.php
+++ b/tests/phpunit/tests/customize/nav-menus.php
@@ -14,6 +14,22 @@ class Test_WP_Customize_Nav_Menus extends WP_UnitTestCase {
 	 */
 	public $wp_customize;
 
+	/**
+	 * ID of the administrator user.
+	 *
+	 * @var int
+	 */
+	public static $administrator_id;
+
+	/**
+	 * Set up the shared fixture.
+	 *
+	 * @param WP_UnitTest_Factory $factory Factory instance.
+	 */
+	public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
+		self::$administrator_id = $factory->user->create( array( 'role' => 'administrator' ) );
+	}
+
 	/**
 	 * Set up a test case.
 	 *
@@ -22,7 +38,7 @@ class Test_WP_Customize_Nav_Menus extends WP_UnitTestCase {
 	public function set_up() {
 		parent::set_up();
 		require_once ABSPATH . WPINC . '/class-wp-customize-manager.php';
-		wp_set_current_user( self::factory()->user->create( array( 'role' => 'administrator' ) ) );
+		wp_set_current_user( self::$administrator_id );
 		global $wp_customize;
 		$this->wp_customize = new WP_Customize_Manager();
 		$wp_customize       = $this->wp_customize;
@@ -856,7 +872,7 @@ public function test_sanitize_nav_menus_created_posts() {
 		$menus                 = new WP_Customize_Nav_Menus( $this->wp_customize );
 		$contributor_user_id   = self::factory()->user->create( array( 'role' => 'contributor' ) );
 		$author_user_id        = self::factory()->user->create( array( 'role' => 'author' ) );
-		$administrator_user_id = self::factory()->user->create( array( 'role' => 'administrator' ) );
+		$administrator_user_id = self::$administrator_id;
 
 		$contributor_post_id   = self::factory()->post->create(
 			array(
diff --git a/tests/phpunit/tests/customize/panel.php b/tests/phpunit/tests/customize/panel.php
index 40f198675a03a..bd191e65d7cd3 100644
--- a/tests/phpunit/tests/customize/panel.php
+++ b/tests/phpunit/tests/customize/panel.php
@@ -7,6 +7,22 @@
  */
 class Tests_WP_Customize_Panel extends WP_UnitTestCase {
 
+	/**
+	 * ID of the administrator user.
+	 *
+	 * @var int
+	 */
+	public static $administrator_id;
+
+	/**
+	 * Set up the shared fixture.
+	 *
+	 * @param WP_UnitTest_Factory $factory Factory instance.
+	 */
+	public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
+		self::$administrator_id = $factory->user->create( array( 'role' => 'administrator' ) );
+	}
+
 	/**
 	 * @var WP_Customize_Manager
 	 */
@@ -131,8 +147,7 @@ public function test_json() {
 	 * @see WP_Customize_Panel::check_capabilities()
 	 */
 	public function test_check_capabilities() {
-		$user_id = self::factory()->user->create( array( 'role' => 'administrator' ) );
-		wp_set_current_user( $user_id );
+		wp_set_current_user( self::$administrator_id );
 
 		$panel = new WP_Customize_Panel( $this->manager, 'foo' );
 		$this->assertTrue( $panel->check_capabilities() );
@@ -157,7 +172,7 @@ public function test_get_content() {
 	 * @see WP_Customize_Panel::maybe_render()
 	 */
 	public function test_maybe_render() {
-		wp_set_current_user( self::factory()->user->create( array( 'role' => 'administrator' ) ) );
+		wp_set_current_user( self::$administrator_id );
 		$panel                        = new WP_Customize_Panel( $this->manager, 'bar' );
 		$customize_render_panel_count = did_action( 'customize_render_panel' );
 		add_action( 'customize_render_panel', array( $this, 'action_customize_render_panel_test' ) );
@@ -182,7 +197,7 @@ public function action_customize_render_panel_test( $panel ) {
 	 * @see WP_Customize_Panel::print_template()
 	 */
 	public function test_print_templates_standard() {
-		wp_set_current_user( self::factory()->user->create( array( 'role' => 'administrator' ) ) );
+		wp_set_current_user( self::$administrator_id );
 
 		$panel = new WP_Customize_Panel( $this->manager, 'baz' );
 		ob_start();
@@ -200,7 +215,7 @@ public function test_print_templates_standard() {
 	 * @see WP_Customize_Panel::print_template()
 	 */
 	public function test_print_templates_custom() {
-		wp_set_current_user( self::factory()->user->create( array( 'role' => 'administrator' ) ) );
+		wp_set_current_user( self::$administrator_id );
 
 		$panel = new Custom_Panel_Test( $this->manager, 'baz' );
 		ob_start();
diff --git a/tests/phpunit/tests/customize/selective-refresh-ajax.php b/tests/phpunit/tests/customize/selective-refresh-ajax.php
index 39d3d45a707f9..8d9305962b7f7 100644
--- a/tests/phpunit/tests/customize/selective-refresh-ajax.php
+++ b/tests/phpunit/tests/customize/selective-refresh-ajax.php
@@ -28,6 +28,22 @@ class Test_WP_Customize_Selective_Refresh_Ajax extends WP_UnitTestCase {
 	 */
 	public $selective_refresh;
 
+	/**
+	 * Shared user ID for the tests.
+	 *
+	 * @var int
+	 */
+	public static $user_id = 0;
+
+	/**
+	 * Set up shared fixtures.
+	 *
+	 * @param WP_UnitTest_Factory $factory Factory.
+	 */
+	public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
+		self::$user_id = $factory->user->create( array( 'role' => 'administrator' ) );
+	}
+
 	/**
 	 * Set up the test fixture.
 	 */
@@ -79,7 +95,7 @@ public function test_handle_render_partials_request_for_unauthenticated_user() {
 		$this->assertSame( 'expected_customize_preview', $output['data'] );
 
 		// Check expected_customize_preview.
-		wp_set_current_user( self::factory()->user->create( array( 'role' => 'administrator' ) ) );
+		wp_set_current_user( self::$user_id );
 		$_REQUEST['nonce'] = wp_create_nonce( 'preview-customize_' . $this->wp_customize->theme()->get_stylesheet() );
 		ob_start();
 		try {
@@ -121,7 +137,7 @@ public function test_handle_render_partials_request_for_unauthenticated_user() {
 	 * Set the current user to be an admin, add the preview nonce, and set the query var.
 	 */
 	private function setup_valid_render_partials_request_environment() {
-		wp_set_current_user( self::factory()->user->create( array( 'role' => 'administrator' ) ) );
+		wp_set_current_user( self::$user_id );
 		$_REQUEST['nonce'] = wp_create_nonce( 'preview-customize_' . $this->wp_customize->theme()->get_stylesheet() );
 		$_POST[ WP_Customize_Selective_Refresh::RENDER_QUERY_VAR ] = '1';
 		$this->do_customize_boot_actions();
@@ -171,7 +187,7 @@ public function test_handle_render_partials_request_for_unrecognized_partial() {
 	 */
 	public function test_handle_render_partials_request_for_non_rendering_partial() {
 		$this->setup_valid_render_partials_request_environment();
-		wp_set_current_user( self::factory()->user->create( array( 'role' => 'administrator' ) ) );
+		wp_set_current_user( self::$user_id );
 		$this->wp_customize->add_setting( 'home' );
 		$this->wp_customize->selective_refresh->add_partial( 'foo', array( 'settings' => array( 'home' ) ) );
 		$context_data = array();
@@ -208,7 +224,7 @@ public function test_handle_render_partials_request_for_non_rendering_partial()
 	 */
 	public function test_handle_rendering_disallowed_partial() {
 		$this->setup_valid_render_partials_request_environment();
-		wp_set_current_user( self::factory()->user->create( array( 'role' => 'administrator' ) ) );
+		wp_set_current_user( self::$user_id );
 		$this->wp_customize->add_setting(
 			'secret_message',
 			array(
@@ -244,7 +260,7 @@ public function test_handle_rendering_disallowed_partial() {
 	 */
 	public function test_handle_rendering_partial_with_missing_settings() {
 		$this->setup_valid_render_partials_request_environment();
-		wp_set_current_user( self::factory()->user->create( array( 'role' => 'administrator' ) ) );
+		wp_set_current_user( self::$user_id );
 		$this->wp_customize->selective_refresh->add_partial( 'bar', array( 'settings' => 'bar' ) );
 
 		$context_data      = array();
diff --git a/tests/phpunit/tests/customize/setting.php b/tests/phpunit/tests/customize/setting.php
index 62861a27264ba..8150a2f03dd82 100644
--- a/tests/phpunit/tests/customize/setting.php
+++ b/tests/phpunit/tests/customize/setting.php
@@ -17,6 +17,22 @@ class Tests_WP_Customize_Setting extends WP_UnitTestCase {
 	 */
 	public $undefined;
 
+	/**
+	 * Shared admin user ID for the tests.
+	 *
+	 * @var int
+	 */
+	public static $admin_id = 0;
+
+	/**
+	 * Set up shared fixtures.
+	 *
+	 * @param WP_UnitTest_Factory $factory Factory.
+	 */
+	public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
+		self::$admin_id = $factory->user->create( array( 'role' => 'administrator' ) );
+	}
+
 	public function set_up() {
 		parent::set_up();
 		require_once ABSPATH . WPINC . '/class-wp-customize-manager.php';
@@ -137,7 +153,7 @@ public function test_constructor_with_args() {
 	 * @see WP_Customize_Setting::value()
 	 */
 	public function test_preview_standard_types_non_multidimensional() {
-		wp_set_current_user( self::factory()->user->create( array( 'role' => 'administrator' ) ) );
+		wp_set_current_user( self::$admin_id );
 		$_POST['customized'] = wp_slash( wp_json_encode( $this->post_data_overrides ) );
 
 		// Try non-multidimensional settings.
@@ -216,7 +232,7 @@ public function test_preview_standard_types_non_multidimensional() {
 	 * @see WP_Customize_Setting::value()
 	 */
 	public function test_preview_standard_types_multidimensional() {
-		wp_set_current_user( self::factory()->user->create( array( 'role' => 'administrator' ) ) );
+		wp_set_current_user( self::$admin_id );
 		$_POST['customized'] = wp_slash( wp_json_encode( $this->post_data_overrides ) );
 
 		foreach ( $this->standard_type_configs as $type => $type_options ) {
@@ -362,7 +378,7 @@ public function custom_type_preview( $setting ) {
 	 * @see WP_Customize_Setting::preview()
 	 */
 	public function test_preview_custom_type() {
-		wp_set_current_user( self::factory()->user->create( array( 'role' => 'administrator' ) ) );
+		wp_set_current_user( self::$admin_id );
 		$type                = 'custom_type';
 		$post_data_overrides = array(
 			"unset_{$type}_with_post_value" => "unset_{$type}_without_post_value\\o/",
@@ -513,7 +529,7 @@ public function test_update_custom_type() {
 		$this->assertTrue( 0 === did_action( 'customize_save_foo' ) );
 
 		// Satisfy all requirements for save to happen.
-		wp_set_current_user( self::factory()->user->create( array( 'role' => 'administrator' ) ) );
+		wp_set_current_user( self::$admin_id );
 		$this->assertNotFalse( $setting->save() );
 		$this->assertTrue( 1 === did_action( 'customize_update_custom' ) );
 		$this->assertTrue( 1 === did_action( 'customize_save_foo' ) );
@@ -551,7 +567,7 @@ public function handle_customize_save_custom_foo_action( $setting ) {
 	 * @ticket 31428
 	 */
 	public function test_is_current_blog_previewed() {
-		wp_set_current_user( self::factory()->user->create( array( 'role' => 'administrator' ) ) );
+		wp_set_current_user( self::$admin_id );
 		$type       = 'option';
 		$name       = 'blogname';
 		$post_value = __FUNCTION__;
@@ -573,7 +589,7 @@ public function test_is_current_blog_previewed() {
 	 * @group ms-required
 	 */
 	public function test_previewing_with_switch_to_blog() {
-		wp_set_current_user( self::factory()->user->create( array( 'role' => 'administrator' ) ) );
+		wp_set_current_user( self::$admin_id );
 		$type       = 'option';
 		$name       = 'blogdescription';
 		$post_value = __FUNCTION__;
@@ -596,7 +612,7 @@ public function test_previewing_with_switch_to_blog() {
 	 */
 	public function test_option_autoloading() {
 		global $wpdb;
-		wp_set_current_user( self::factory()->user->create( array( 'role' => 'administrator' ) ) );
+		wp_set_current_user( self::$admin_id );
 
 		$name    = 'autoloaded1';
 		$setting = new WP_Customize_Setting(
@@ -743,7 +759,7 @@ public function filter_validate_for_test_validate( $validity, $value ) {
 	 * @ticket 37294
 	 */
 	public function test_multidimensional_value_when_previewed() {
-		wp_set_current_user( self::factory()->user->create( array( 'role' => 'administrator' ) ) );
+		wp_set_current_user( self::$admin_id );
 		WP_Customize_Setting::reset_aggregated_multidimensionals();
 
 		$initial_value = 456;
diff --git a/tests/phpunit/tests/customize/widgets.php b/tests/phpunit/tests/customize/widgets.php
index 77b141944099a..bf298e1fffeb3 100644
--- a/tests/phpunit/tests/customize/widgets.php
+++ b/tests/phpunit/tests/customize/widgets.php
@@ -20,6 +20,22 @@ class Tests_WP_Customize_Widgets extends WP_UnitTestCase {
 	 */
 	protected $backup_registered_sidebars;
 
+	/**
+	 * ID of the administrator user.
+	 *
+	 * @var int
+	 */
+	public static $administrator_id;
+
+	/**
+	 * Set up the shared fixture.
+	 *
+	 * @param WP_UnitTest_Factory $factory Factory instance.
+	 */
+	public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
+		self::$administrator_id = $factory->user->create( array( 'role' => 'administrator' ) );
+	}
+
 	public function set_up() {
 		parent::set_up();
 		require_once ABSPATH . WPINC . '/class-wp-customize-manager.php';
@@ -27,8 +43,7 @@ public function set_up() {
 		add_theme_support( 'customize-selective-refresh-widgets' );
 		add_action( 'widgets_init', array( $this, 'remove_widgets_block_editor' ) );
 
-		$user_id = self::factory()->user->create( array( 'role' => 'administrator' ) );
-		wp_set_current_user( $user_id );
+		wp_set_current_user( self::$administrator_id );
 
 		update_option(
 			'widget_search',
diff --git a/tests/phpunit/tests/general/template.php b/tests/phpunit/tests/general/template.php
index 5aaf93be4e0bd..d3b35a2c46c2b 100644
--- a/tests/phpunit/tests/general/template.php
+++ b/tests/phpunit/tests/general/template.php
@@ -32,7 +32,29 @@ class Tests_General_Template extends WP_UnitTestCase {
 	 */
 	public static $home_page_id;
 
+	/**
+	 * ID of the administrator user.
+	 *
+	 * @var int
+	 */
+	public static $administrator_id;
+
+	/**
+	 * ID of the author user.
+	 *
+	 * @var int
+	 */
+	public static $author_id;
+
+	/**
+	 * Set up the shared fixtures.
+	 *
+	 * @param WP_UnitTest_Factory $factory Factory instance.
+	 */
 	public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
+		self::$administrator_id = $factory->user->create( array( 'role' => 'administrator' ) );
+		self::$author_id        = $factory->user->create( array( 'role' => 'author' ) );
+
 		/*
 		 * Declare theme support for custom logo.
 		 *
@@ -212,7 +234,7 @@ public function test_wp_site_icon_with_filter() {
 	 */
 	public function test_customize_preview_wp_site_icon_empty() {
 		global $wp_customize;
-		wp_set_current_user( self::factory()->user->create( array( 'role' => 'administrator' ) ) );
+		wp_set_current_user( self::$administrator_id );
 
 		require_once ABSPATH . WPINC . '/class-wp-customize-manager.php';
 		$wp_customize = new WP_Customize_Manager();
@@ -230,7 +252,7 @@ public function test_customize_preview_wp_site_icon_empty() {
 	 */
 	public function test_customize_preview_wp_site_icon_dirty() {
 		global $wp_customize;
-		wp_set_current_user( self::factory()->user->create( array( 'role' => 'administrator' ) ) );
+		wp_set_current_user( self::$administrator_id );
 
 		require_once ABSPATH . WPINC . '/class-wp-customize-manager.php';
 		$wp_customize = new WP_Customize_Manager();
@@ -763,16 +785,8 @@ public function test_get_template_part_passes_arguments_to_template() {
 	 * @covers ::get_the_archive_title
 	 */
 	public function test_get_the_archive_title_is_correct_for_author_queries() {
-		$user_with_posts    = self::factory()->user->create_and_get(
-			array(
-				'role' => 'author',
-			)
-		);
-		$user_with_no_posts = self::factory()->user->create_and_get(
-			array(
-				'role' => 'author',
-			)
-		);
+		$user_with_posts    = get_user_by( 'id', self::$administrator_id );
+		$user_with_no_posts = get_user_by( 'id', self::$author_id );
 
 		self::factory()->post->create(
 			array(
diff --git a/tests/phpunit/tests/l10n.php b/tests/phpunit/tests/l10n.php
index 7926a804da5fc..2f7992c34069f 100644
--- a/tests/phpunit/tests/l10n.php
+++ b/tests/phpunit/tests/l10n.php
@@ -15,6 +15,17 @@ class Tests_L10n extends WP_UnitTestCase {
 	 */
 	private $long_text = 'Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.';
 
+	/**
+	 * Editor user ID.
+	 *
+	 * @var int $editor_id
+	 */
+	public static $editor_id;
+
+	public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
+		self::$editor_id = $factory->user->create( array( 'role' => 'editor' ) );
+	}
+
 	/**
 	 * @ticket 35961
 	 *
@@ -464,7 +475,7 @@ public function test_length_of_draft_should_be_counted_by_words() {
 		 * and return a string instead of null, which would otherwise cause a PHP 8.1
 		 * "passing null to non-nullable" deprecation notice.
 		 */
-		wp_set_current_user( self::factory()->user->create( array( 'role' => 'editor' ) ) );
+		wp_set_current_user( self::$editor_id );
 
 		$args = array(
 			'post_content' => $this->long_text,
@@ -503,7 +514,7 @@ public function test_length_of_draft_should_be_counted_by_chars() {
 		 * and return a string instead of null, which would otherwise cause a PHP 8.1
 		 * "passing null to non-nullable" deprecation notice.
 		 */
-		wp_set_current_user( self::factory()->user->create( array( 'role' => 'editor' ) ) );
+		wp_set_current_user( self::$editor_id );
 
 		$args = array(
 			'post_content' => $this->long_text,
@@ -542,7 +553,7 @@ public function test_length_of_draft_should_be_counted_by_chars_in_japanese() {
 		 * and return a string instead of null, which would otherwise cause a PHP 8.1
 		 * "passing null to non-nullable" deprecation notice.
 		 */
-		wp_set_current_user( self::factory()->user->create( array( 'role' => 'editor' ) ) );
+		wp_set_current_user( self::$editor_id );
 
 		$args = array(
 			'post_content' => str_repeat( 'あ', 200 ),
diff --git a/tests/phpunit/tests/l10n/getUserLocale.php b/tests/phpunit/tests/l10n/getUserLocale.php
index 76492b3b707f6..e4eaf7a2601bc 100644
--- a/tests/phpunit/tests/l10n/getUserLocale.php
+++ b/tests/phpunit/tests/l10n/getUserLocale.php
@@ -9,34 +9,61 @@
 class Tests_L10n_GetUserLocale extends WP_UnitTestCase {
 	protected $user_id;
 
-	public function set_up() {
-		parent::set_up();
+	/**
+	 * ID of the administrator user with de_DE local.
+	 *
+	 * @var int
+	 */
+	public static $administrator_de_de;
+
+	/**
+	 * ID of the user with es_ES local.
+	 *
+	 * @var int
+	 */
+	public static $user_es_es;
 
-		$this->user_id = self::factory()->user->create(
+	/**
+	 * Set up the shared fixtures.
+	 *
+	 * @param WP_UnitTest_Factory $factory Factory instance.
+	 */
+	public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
+		self::$administrator_de_de = $factory->user->create(
 			array(
 				'role'   => 'administrator',
 				'locale' => 'de_DE',
 			)
 		);
 
-		wp_set_current_user( $this->user_id );
+		self::$user_es_es = self::factory()->user->create(
+			array(
+				'locale' => 'es_ES',
+			)
+		);
+	}
+
+	public function set_up() {
+		parent::set_up();
+
+		wp_set_current_user( self::$administrator_de_de );
 	}
 
 	public function test_user_locale_property() {
 		set_current_screen( 'dashboard' );
 		$this->assertSame( 'de_DE', get_user_locale() );
-		$this->assertSame( get_user_by( 'id', $this->user_id )->locale, get_user_locale() );
+		$this->assertSame( get_user_by( 'id', self::$administrator_de_de )->locale, get_user_locale() );
 	}
 
 	public function test_update_user_locale() {
 		set_current_screen( 'dashboard' );
-		update_user_meta( $this->user_id, 'locale', 'fr_FR' );
+		update_user_meta( self::$administrator_de_de, 'locale', 'fr_FR' );
 		$this->assertSame( 'fr_FR', get_user_locale() );
 	}
 
 	public function test_returns_site_locale_if_empty() {
 		set_current_screen( 'dashboard' );
-		update_user_meta( $this->user_id, 'locale', '' );
+		update_user_meta( self::$administrator_de_de, 'locale', '' );
 		$this->assertSame( get_locale(), get_user_locale() );
 	}
 
@@ -78,11 +105,7 @@ public function test_user_locale_is_same_across_network() {
 	}
 
 	public function test_user_id_argument_with_id() {
-		$user_id = self::factory()->user->create(
-			array(
-				'locale' => 'es_ES',
-			)
-		);
+		$user_id = self::$user_es_es;
 
 		$user_locale1 = get_user_locale( $user_id );
 
@@ -95,11 +118,7 @@ public function test_user_id_argument_with_id() {
 	}
 
 	public function test_user_id_argument_with_wp_user_object() {
-		$user_id = self::factory()->user->create(
-			array(
-				'locale' => 'es_ES',
-			)
-		);
+		$user_id = self::$user_es_es;
 
 		$user = get_user_by( 'id', $user_id );
 
diff --git a/tests/phpunit/tests/meta.php b/tests/phpunit/tests/meta.php
index 857414190a2c3..6f84587cf2aaa 100644
--- a/tests/phpunit/tests/meta.php
+++ b/tests/phpunit/tests/meta.php
@@ -9,16 +9,15 @@ class Tests_Meta extends WP_UnitTestCase {
 	/**
 	 * @var \WP_User
 	 */
-	private $author;
+	private static $author;
 
-	private $meta_id;
-	private $delete_meta_id;
+	private static $meta_id;
+	private static $delete_meta_id;
 
-	public function set_up() {
-		parent::set_up();
-		$this->author         = new WP_User( self::factory()->user->create( array( 'role' => 'author' ) ) );
-		$this->meta_id        = add_metadata( 'user', $this->author->ID, 'meta_key', 'meta_value' );
-		$this->delete_meta_id = add_metadata( 'user', $this->author->ID, 'delete_meta_key', 'delete_meta_value' );
+	public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
+		self::$author         = new WP_User( $factory->user->create( array( 'role' => 'author' ) ) );
+		self::$meta_id        = add_metadata( 'user', self::$author->ID, 'meta_key', 'meta_value' );
+		self::$delete_meta_id = add_metadata( 'user', self::$author->ID, 'delete_meta_key', 'delete_meta_value' );
 	}
 
 	public function meta_sanitize_cb( $meta_value, $meta_key, $meta_type ) {
@@ -37,51 +36,51 @@ public function test_sanitize_meta() {
 	public function test_delete_metadata_by_mid() {
 		// Let's try and delete a non-existing ID, non existing meta.
 		$this->assertFalse( delete_metadata_by_mid( 'user', 0 ) );
-		$this->assertFalse( delete_metadata_by_mid( 'non_existing_meta', $this->delete_meta_id ) );
+		$this->assertFalse( delete_metadata_by_mid( 'non_existing_meta', self::$delete_meta_id ) );
 
 		// Now let's delete the real meta data.
-		$this->assertTrue( delete_metadata_by_mid( 'user', $this->delete_meta_id ) );
+		$this->assertTrue( delete_metadata_by_mid( 'user', self::$delete_meta_id ) );
 
 		// And make sure it's been deleted.
-		$this->assertFalse( get_metadata_by_mid( 'user', $this->delete_meta_id ) );
+		$this->assertFalse( get_metadata_by_mid( 'user', self::$delete_meta_id ) );
 
 		// Make sure the caches are cleared.
-		$this->assertFalse( (bool) get_user_meta( $this->author->ID, 'delete_meta_key' ) );
+		$this->assertFalse( (bool) get_user_meta( self::$author->ID, 'delete_meta_key' ) );
 	}
 
 	public function test_update_metadata_by_mid() {
 		// Setup.
-		$meta = get_metadata_by_mid( 'user', $this->meta_id );
+		$meta = get_metadata_by_mid( 'user', self::$meta_id );
 
 		// Update the meta value.
-		$this->assertTrue( update_metadata_by_mid( 'user', $this->meta_id, 'meta_new_value' ) );
-		$meta = get_metadata_by_mid( 'user', $this->meta_id );
+		$this->assertTrue( update_metadata_by_mid( 'user', self::$meta_id, 'meta_new_value' ) );
+		$meta = get_metadata_by_mid( 'user', self::$meta_id );
 		$this->assertSame( 'meta_new_value', $meta->meta_value );
 
 		// Update the meta value.
-		$this->assertTrue( update_metadata_by_mid( 'user', $this->meta_id, 'meta_new_value', 'meta_new_key' ) );
-		$meta = get_metadata_by_mid( 'user', $this->meta_id );
+		$this->assertTrue( update_metadata_by_mid( 'user', self::$meta_id, 'meta_new_value', 'meta_new_key' ) );
+		$meta = get_metadata_by_mid( 'user', self::$meta_id );
 		$this->assertSame( 'meta_new_key', $meta->meta_key );
 
 		// Update the key and value.
-		$this->assertTrue( update_metadata_by_mid( 'user', $this->meta_id, 'meta_value', 'meta_key' ) );
-		$meta = get_metadata_by_mid( 'user', $this->meta_id );
+		$this->assertTrue( update_metadata_by_mid( 'user', self::$meta_id, 'meta_value', 'meta_key' ) );
+		$meta = get_metadata_by_mid( 'user', self::$meta_id );
 		$this->assertSame( 'meta_key', $meta->meta_key );
 		$this->assertSame( 'meta_value', $meta->meta_value );
 
 		// Update the value that has to be serialized.
-		$this->assertTrue( update_metadata_by_mid( 'user', $this->meta_id, array( 'first', 'second' ) ) );
-		$meta = get_metadata_by_mid( 'user', $this->meta_id );
+		$this->assertTrue( update_metadata_by_mid( 'user', self::$meta_id, array( 'first', 'second' ) ) );
+		$meta = get_metadata_by_mid( 'user', self::$meta_id );
 		$this->assertSame( array( 'first', 'second' ), $meta->meta_value );
 
 		// Let's try some invalid meta data.
 		$this->assertFalse( update_metadata_by_mid( 'user', 0, 'meta_value' ) );
-		$this->assertFalse( update_metadata_by_mid( 'user', $this->meta_id, 'meta_value', array( 'invalid', 'key' ) ) );
+		$this->assertFalse( update_metadata_by_mid( 'user', self::$meta_id, 'meta_value', array( 'invalid', 'key' ) ) );
 
 		// Let's see if caches get cleared after updates.
-		$meta  = get_metadata_by_mid( 'user', $this->meta_id );
+		$meta  = get_metadata_by_mid( 'user', self::$meta_id );
 		$first = get_user_meta( $meta->user_id, $meta->meta_key );
-		$this->assertTrue( update_metadata_by_mid( 'user', $this->meta_id, 'other_meta_value' ) );
+		$this->assertTrue( update_metadata_by_mid( 'user', self::$meta_id, 'other_meta_value' ) );
 		$second = get_user_meta( $meta->user_id, $meta->meta_key );
 		$this->assertFalse( $first === $second );
 	}
@@ -113,8 +112,8 @@ public function test_update_metadata_hooks_for_multiple_updated_rows() {
 	}
 
 	public function test_metadata_exists() {
-		$this->assertFalse( metadata_exists( 'user', $this->author->ID, 'foobarbaz' ) );
-		$this->assertTrue( metadata_exists( 'user', $this->author->ID, 'meta_key' ) );
+		$this->assertFalse( metadata_exists( 'user', self::$author->ID, 'foobarbaz' ) );
+		$this->assertTrue( metadata_exists( 'user', self::$author->ID, 'meta_key' ) );
 		$this->assertFalse( metadata_exists( 'user', 1234567890, 'foobarbaz' ) );
 		$this->assertFalse( metadata_exists( 'user', 1234567890, 'meta_key' ) );
 	}
@@ -125,7 +124,7 @@ public function test_metadata_exists() {
 	public function test_metadata_exists_with_filter() {
 		// Let's see if it returns the correct value when adding a filter.
 		add_filter( 'get_user_metadata', '__return_zero' );
-		$this->assertFalse( metadata_exists( 'user', $this->author->ID, 'meta_key' ) ); // Existing meta key.
+		$this->assertFalse( metadata_exists( 'user', self::$author->ID, 'meta_key' ) ); // Existing meta key.
 		$this->assertFalse( metadata_exists( 'user', 1234567890, 'meta_key' ) );
 		remove_filter( 'get_user_metadata', '__return_zero' );
 	}
@@ -148,7 +147,7 @@ public function test_user_metadata_not_exists() {
 		$this->assertCount( 1, $u );
 
 		// User found is not locally defined author (it's the admin).
-		$this->assertNotEquals( $this->author->user_login, $u[0]->user_login );
+		$this->assertNotEquals( self::$author->user_login, $u[0]->user_login );
 
 		// Test EXISTS and NOT EXISTS together, no users should be found.
 		$this->assertCount(
@@ -183,7 +182,7 @@ public function test_user_metadata_not_exists() {
 			)
 		);
 
-		delete_metadata( 'user', $this->author->ID, 'meta_key' );
+		delete_metadata( 'user', self::$author->ID, 'meta_key' );
 
 		$this->assertCount(
 			2,
@@ -206,28 +205,28 @@ public function test_metadata_slashes() {
 		$expected  = 'Testsingleslash';
 		$value2    = 'Test\\\\doubleslash';
 		$expected2 = 'Test\\doubleslash';
-		$this->assertFalse( metadata_exists( 'user', $this->author->ID, $key ) );
-		$this->assertFalse( delete_metadata( 'user', $this->author->ID, $key ) );
-		$this->assertSame( '', get_metadata( 'user', $this->author->ID, $key, true ) );
-		$this->assertIsInt( add_metadata( 'user', $this->author->ID, $key, $value ) );
-		$this->assertSame( $expected, get_metadata( 'user', $this->author->ID, $key, true ) );
-		$this->assertTrue( delete_metadata( 'user', $this->author->ID, $key ) );
-		$this->assertSame( '', get_metadata( 'user', $this->author->ID, $key, true ) );
-		$this->assertIsInt( update_metadata( 'user', $this->author->ID, $key, $value ) );
-		$this->assertSame( $expected, get_metadata( 'user', $this->author->ID, $key, true ) );
-		$this->assertTrue( update_metadata( 'user', $this->author->ID, $key, 'blah' ) );
-		$this->assertSame( 'blah', get_metadata( 'user', $this->author->ID, $key, true ) );
-		$this->assertTrue( delete_metadata( 'user', $this->author->ID, $key ) );
-		$this->assertSame( '', get_metadata( 'user', $this->author->ID, $key, true ) );
-		$this->assertFalse( metadata_exists( 'user', $this->author->ID, $key ) );
+		$this->assertFalse( metadata_exists( 'user', self::$author->ID, $key ) );
+		$this->assertFalse( delete_metadata( 'user', self::$author->ID, $key ) );
+		$this->assertSame( '', get_metadata( 'user', self::$author->ID, $key, true ) );
+		$this->assertIsInt( add_metadata( 'user', self::$author->ID, $key, $value ) );
+		$this->assertSame( $expected, get_metadata( 'user', self::$author->ID, $key, true ) );
+		$this->assertTrue( delete_metadata( 'user', self::$author->ID, $key ) );
+		$this->assertSame( '', get_metadata( 'user', self::$author->ID, $key, true ) );
+		$this->assertIsInt( update_metadata( 'user', self::$author->ID, $key, $value ) );
+		$this->assertSame( $expected, get_metadata( 'user', self::$author->ID, $key, true ) );
+		$this->assertTrue( update_metadata( 'user', self::$author->ID, $key, 'blah' ) );
+		$this->assertSame( 'blah', get_metadata( 'user', self::$author->ID, $key, true ) );
+		$this->assertTrue( delete_metadata( 'user', self::$author->ID, $key ) );
+		$this->assertSame( '', get_metadata( 'user', self::$author->ID, $key, true ) );
+		$this->assertFalse( metadata_exists( 'user', self::$author->ID, $key ) );
 
 		// Test overslashing.
-		$this->assertIsInt( add_metadata( 'user', $this->author->ID, $key, $value2 ) );
-		$this->assertSame( $expected2, get_metadata( 'user', $this->author->ID, $key, true ) );
-		$this->assertTrue( delete_metadata( 'user', $this->author->ID, $key ) );
-		$this->assertSame( '', get_metadata( 'user', $this->author->ID, $key, true ) );
-		$this->assertIsInt( update_metadata( 'user', $this->author->ID, $key, $value2 ) );
-		$this->assertSame( $expected2, get_metadata( 'user', $this->author->ID, $key, true ) );
+		$this->assertIsInt( add_metadata( 'user', self::$author->ID, $key, $value2 ) );
+		$this->assertSame( $expected2, get_metadata( 'user', self::$author->ID, $key, true ) );
+		$this->assertTrue( delete_metadata( 'user', self::$author->ID, $key ) );
+		$this->assertSame( '', get_metadata( 'user', self::$author->ID, $key, true ) );
+		$this->assertIsInt( update_metadata( 'user', self::$author->ID, $key, $value2 ) );
+		$this->assertSame( $expected2, get_metadata( 'user', self::$author->ID, $key, true ) );
 	}
 
 	/**
@@ -344,7 +343,7 @@ public function test_non_numeric_meta_id() {
 	 * @ticket 37746
 	 */
 	public function test_negative_meta_id() {
-		$negative_mid = $this->meta_id * -1;
+		$negative_mid = self::$meta_id * -1;
 
 		$this->assertLessThan( 0, $negative_mid );
 		$this->assertFalse( get_metadata_by_mid( 'user', $negative_mid ) );
@@ -356,7 +355,7 @@ public function test_negative_meta_id() {
 	 * @ticket 37746
 	 */
 	public function test_floating_meta_id() {
-		$floating_mid = $this->meta_id + 0.1337;
+		$floating_mid = self::$meta_id + 0.1337;
 
 		$this->assertTrue( floor( $floating_mid ) !== $floating_mid );
 		$this->assertFalse( get_metadata_by_mid( 'user', $floating_mid ) );
@@ -368,7 +367,7 @@ public function test_floating_meta_id() {
 	 * @ticket 37746
 	 */
 	public function test_string_point_zero_meta_id() {
-		$meta_id = add_metadata( 'user', $this->author->ID, 'meta_key', 'meta_value_2' );
+		$meta_id = add_metadata( 'user', self::$author->ID, 'meta_key', 'meta_value_2' );
 
 		$string_mid = "{$meta_id}.0";
 
@@ -385,8 +384,8 @@ public function test_string_point_zero_meta_id() {
 	public function test_get_metadata_with_empty_key_array_value() {
 		$data  = array( 1, 2 );
 		$value = serialize( $data );
-		add_metadata( 'user', $this->author->ID, 'foo', $data );
-		$found = get_metadata( 'user', $this->author->ID );
+		add_metadata( 'user', self::$author->ID, 'foo', $data );
+		$found = get_metadata( 'user', self::$author->ID );
 
 		$this->assertSame( array( $value ), $found['foo'] );
 	}
@@ -398,8 +397,8 @@ public function test_get_metadata_with_empty_key_object_value() {
 		$data      = new stdClass();
 		$data->foo = 'bar';
 		$value     = serialize( $data );
-		add_metadata( 'user', $this->author->ID, 'foo', $data );
-		$found = get_metadata( 'user', $this->author->ID );
+		add_metadata( 'user', self::$author->ID, 'foo', $data );
+		$found = get_metadata( 'user', self::$author->ID );
 
 		$this->assertSame( array( $value ), $found['foo'] );
 	}
@@ -413,8 +412,8 @@ public function test_get_metadata_with_empty_key_nested_array_value() {
 			array( 3, 4 ),
 		);
 		$value = serialize( $data );
-		add_metadata( 'user', $this->author->ID, 'foo', $data );
-		$found = get_metadata( 'user', $this->author->ID );
+		add_metadata( 'user', self::$author->ID, 'foo', $data );
+		$found = get_metadata( 'user', self::$author->ID );
 
 		$this->assertSame( array( $value ), $found['foo'] );
 	}
diff --git a/tests/phpunit/tests/oembed/controller.php b/tests/phpunit/tests/oembed/controller.php
index 9011b789bb2e7..aa0275c4c87ee 100644
--- a/tests/phpunit/tests/oembed/controller.php
+++ b/tests/phpunit/tests/oembed/controller.php
@@ -304,11 +304,7 @@ public function test_request_invalid_format() {
 	}
 
 	public function test_request_json() {
-		$user = self::factory()->user->create_and_get(
-			array(
-				'display_name' => 'John Doe',
-			)
-		);
+		$user = get_user_by( 'id', self::$subscriber );
 		$post = self::factory()->post->create_and_get(
 			array(
 				'post_author' => $user->ID,
@@ -391,11 +387,7 @@ public function test_request_static_front_page() {
 	}
 
 	public function test_request_xml() {
-		$user = self::factory()->user->create_and_get(
-			array(
-				'display_name' => 'John Doe',
-			)
-		);
+		$user = get_user_by( 'id', self::$subscriber );
 		$post = self::factory()->post->create_and_get(
 			array(
 				'post_author' => $user->ID,
@@ -461,11 +453,7 @@ public function test_request_ms_child_in_root_blog() {
 	}
 
 	public function test_rest_pre_serve_request() {
-		$user = self::factory()->user->create_and_get(
-			array(
-				'display_name' => 'John Doe',
-			)
-		);
+		$user = get_user_by( 'id', self::$subscriber );
 		$post = self::factory()->post->create_and_get(
 			array(
 				'post_author' => $user->ID,
@@ -677,11 +665,7 @@ public function test_proxy_with_invalid_discover_param() {
 	public function test_proxy_with_internal_url() {
 		wp_set_current_user( self::$editor );
 
-		$user = self::factory()->user->create_and_get(
-			array(
-				'display_name' => 'John Doe',
-			)
-		);
+		$user = get_user_by( 'id', self::$subscriber );
 		$post = self::factory()->post->create_and_get(
 			array(
 				'post_author' => $user->ID,
diff --git a/tests/phpunit/tests/oembed/wpOembed.php b/tests/phpunit/tests/oembed/wpOembed.php
index 051a7efe3d847..76d733dbce2e0 100644
--- a/tests/phpunit/tests/oembed/wpOembed.php
+++ b/tests/phpunit/tests/oembed/wpOembed.php
@@ -11,6 +11,22 @@ class Tests_WP_oEmbed extends WP_UnitTestCase {
 
 	public $pre_oembed_result_filtered = false;
 
+	/**
+	 * ID of the user.
+	 *
+	 * @var int
+	 */
+	public static $user_id;
+
+	/**
+	 * Set up the shared fixture.
+	 *
+	 * @param WP_UnitTest_Factory $factory Factory instance.
+	 */
+	public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
+		self::$user_id = $factory->user->create();
+	}
+
 	public function set_up() {
 		parent::set_up();
 
@@ -96,7 +112,7 @@ public function test_wp_filter_pre_oembed_result_multisite_root_root() {
 	 * @group ms-required
 	 */
 	public function test_wp_filter_pre_oembed_result_multisite_sub_samesub() {
-		$user_id = self::factory()->user->create();
+		$user_id = self::$user_id;
 
 		$blog_id = self::factory()->blog->create(
 			array(
@@ -125,7 +141,7 @@ public function test_wp_filter_pre_oembed_result_multisite_sub_samesub() {
 	 * @group ms-required
 	 */
 	public function test_wp_filter_pre_oembed_result_multisite_sub_othersub() {
-		$user_id = self::factory()->user->create();
+		$user_id = self::$user_id;
 
 		$blog_id = self::factory()->blog->create(
 			array(
@@ -164,7 +180,7 @@ public function test_wp_filter_pre_oembed_result_multisite_sub_othersub() {
 	public function test_wp_filter_pre_oembed_result_multisite_sub_main() {
 		$post_id   = self::factory()->post->create();
 		$permalink = get_permalink( $post_id );
-		$user_id   = self::factory()->user->create();
+		$user_id   = self::$user_id;
 		$blog_id   = self::factory()->blog->create(
 			array(
 				'user_id' => $user_id,
@@ -189,7 +205,7 @@ public function test_wp_filter_pre_oembed_result_multisite_sub_main() {
 	 * @group ms-required
 	 */
 	public function test_wp_filter_pre_oembed_result_multisite_preserves_switched_state() {
-		$user_id = self::factory()->user->create();
+		$user_id = self::$user_id;
 
 		$blog_id = self::factory()->blog->create( array( 'user_id' => $user_id ) );
 		switch_to_blog( $blog_id );
@@ -220,7 +236,7 @@ public function test_wp_filter_pre_oembed_result_multisite_preserves_switched_st
 	public function test_wp_filter_pre_oembed_result_multisite_restores_state_if_no_post_is_found() {
 		$current_blog_id = get_current_blog_id();
 
-		$user_id = self::factory()->user->create();
+		$user_id = self::$user_id;
 		$blog_id = self::factory()->blog->create(
 			array(
 				'user_id' => $user_id,
diff --git a/tests/phpunit/tests/post/getPages.php b/tests/phpunit/tests/post/getPages.php
index 76735bae86296..dad85ddc69367 100644
--- a/tests/phpunit/tests/post/getPages.php
+++ b/tests/phpunit/tests/post/getPages.php
@@ -6,6 +6,42 @@
  * @covers ::get_pages
  */
 class Tests_Post_GetPages extends WP_UnitTestCase {
+
+	/**
+	 * ID of the first author.
+	 *
+	 * @var int
+	 */
+	public static $author_id_1;
+
+	/**
+	 * ID of the second author.
+	 *
+	 * @var int
+	 */
+	public static $author_id_2;
+
+	/**
+	 * Set up the shared fixture.
+	 *
+	 * @param WP_UnitTest_Factory $factory Factory instance.
+	 */
+	public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
+		self::$author_id_1 = $factory->user->create(
+			array(
+				'user_login' => 'author1',
+				'role'       => 'author',
+			)
+		);
+
+		self::$author_id_2 = $factory->user->create(
+			array(
+				'user_login' => 'author2',
+				'role'       => 'author',
+			)
+		);
+	}
+
 	/**
 	 * @ticket 23167
 	 */
@@ -963,12 +999,7 @@ public function test_get_pages_offset() {
 	 * @ticket 12821
 	 */
 	public function test_get_pages_author() {
-		$author_1 = self::factory()->user->create(
-			array(
-				'user_login' => 'author1',
-				'role'       => 'author',
-			)
-		);
+		$author_1 = self::$author_id_1;
 		$posts    = self::factory()->post->create_many(
 			2,
 			array(
@@ -989,12 +1020,7 @@ public function test_get_pages_author() {
 	 * @ticket 12821
 	 */
 	public function test_get_pages_multiple_authors() {
-		$author_1 = self::factory()->user->create(
-			array(
-				'user_login' => 'author1',
-				'role'       => 'author',
-			)
-		);
+		$author_1 = self::$author_id_1;
 		$post_1   = self::factory()->post->create(
 			array(
 				'post_title'  => 'Page 1',
@@ -1004,12 +1030,7 @@ public function test_get_pages_multiple_authors() {
 			)
 		);
 
-		$author_2 = self::factory()->user->create(
-			array(
-				'user_login' => 'author2',
-				'role'       => 'author',
-			)
-		);
+		$author_2 = self::$author_id_2;
 		$post_2   = self::factory()->post->create(
 			array(
 				'post_title'  => 'Page 2',
@@ -1031,12 +1052,7 @@ public function test_get_pages_multiple_authors() {
 	 * @ticket 12821
 	 */
 	public function test_get_pages_multiple_authors_by_user_login() {
-		$author_1 = self::factory()->user->create(
-			array(
-				'user_login' => 'author1',
-				'role'       => 'author',
-			)
-		);
+		$author_1 = self::$author_id_1;
 		$post_1   = self::factory()->post->create(
 			array(
 				'post_title'  => 'Page 1',
@@ -1046,12 +1062,7 @@ public function test_get_pages_multiple_authors_by_user_login() {
 			)
 		);
 
-		$author_2 = self::factory()->user->create(
-			array(
-				'user_login' => 'author2',
-				'role'       => 'author',
-			)
-		);
+		$author_2 = self::$author_id_2;
 		$post_2   = self::factory()->post->create(
 			array(
 				'post_title'  => 'Page 2',
diff --git a/tests/phpunit/tests/post/getPostsByAuthorSql.php b/tests/phpunit/tests/post/getPostsByAuthorSql.php
index fc6f1e85267d9..e2657a3fdf11c 100644
--- a/tests/phpunit/tests/post/getPostsByAuthorSql.php
+++ b/tests/phpunit/tests/post/getPostsByAuthorSql.php
@@ -5,6 +5,30 @@
  */
 class Tests_Post_GetPostsByAuthorSql extends WP_UnitTestCase {
 
+	/**
+	 * ID of the first user.
+	 *
+	 * @var int
+	 */
+	public static $user_id_1;
+
+	/**
+	 * ID of the second user.
+	 *
+	 * @var int
+	 */
+	public static $user_id_2;
+
+	/**
+	 * Set up the shared fixture.
+	 *
+	 * @param WP_UnitTest_Factory $factory Factory instance.
+	 */
+	public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
+		self::$user_id_1 = $factory->user->create();
+		self::$user_id_2 = $factory->user->create();
+	}
+
 	public function test_post_type_post() {
 		$maybe_string = get_posts_by_author_sql( 'post' );
 		$this->assertStringContainsString( "post_type = 'post'", $maybe_string );
@@ -59,7 +83,7 @@ public function test_post_author_should_create_post_author_clause() {
 
 	public function test_public_only_true_should_not_allow_any_private_posts_for_loggedin_user() {
 		$current_user = get_current_user_id();
-		$u            = self::factory()->user->create();
+		$u            = self::$user_id_1;
 		wp_set_current_user( $u );
 
 		$maybe_string = get_posts_by_author_sql( 'post', true, $u, true );
@@ -70,7 +94,7 @@ public function test_public_only_true_should_not_allow_any_private_posts_for_log
 
 	public function test_public_only_should_default_to_false() {
 		$current_user = get_current_user_id();
-		$u            = self::factory()->user->create();
+		$u            = self::$user_id_1;
 		wp_set_current_user( $u );
 
 		$this->assertSame( get_posts_by_author_sql( 'post', true, $u, false ), get_posts_by_author_sql( 'post', true, $u ) );
@@ -80,7 +104,7 @@ public function test_public_only_should_default_to_false() {
 
 	public function test_public_only_false_should_allow_current_user_access_to_own_private_posts_when_current_user_matches_post_author() {
 		$current_user = get_current_user_id();
-		$u            = self::factory()->user->create();
+		$u            = self::$user_id_1;
 		wp_set_current_user( $u );
 
 		$maybe_string = get_posts_by_author_sql( 'post', true, $u, false );
@@ -91,8 +115,8 @@ public function test_public_only_false_should_allow_current_user_access_to_own_p
 
 	public function test_public_only_false_should_not_allow_access_to_private_posts_if_current_user_is_not_post_author() {
 		$current_user = get_current_user_id();
-		$u1           = self::factory()->user->create();
-		$u2           = self::factory()->user->create();
+		$u1           = self::$user_id_1;
+		$u2           = self::$user_id_2;
 		wp_set_current_user( $u1 );
 
 		$maybe_string = get_posts_by_author_sql( 'post', true, $u2, false );
@@ -103,7 +127,7 @@ public function test_public_only_false_should_not_allow_access_to_private_posts_
 
 	public function test_public_only_false_should_allow_current_user_access_to_own_private_posts_when_post_author_is_not_provided() {
 		$current_user = get_current_user_id();
-		$u            = self::factory()->user->create();
+		$u            = self::$user_id_1;
 		wp_set_current_user( $u );
 
 		$maybe_string = get_posts_by_author_sql( 'post', true, $u, false );
diff --git a/tests/phpunit/tests/query/conditionals.php b/tests/phpunit/tests/query/conditionals.php
index 05278ffd7a4cd..4b473178897ae 100644
--- a/tests/phpunit/tests/query/conditionals.php
+++ b/tests/phpunit/tests/query/conditionals.php
@@ -14,6 +14,22 @@ class Tests_Query_Conditionals extends WP_UnitTestCase {
 	protected $page_ids;
 	protected $post_ids;
 
+	/**
+	 * ID of the user-a.
+	 *
+	 * @var int
+	 */
+	public static $user_a_id;
+
+	/**
+	 * Set up the shared fixture.
+	 *
+	 * @param WP_UnitTest_Factory $factory Factory instance.
+	 */
+	public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
+		self::$user_a_id = $factory->user->create( array( 'user_login' => 'user-a' ) );
+	}
+
 	public function set_up() {
 		parent::set_up();
 
@@ -588,7 +604,6 @@ public function test_tag() {
 	// 'author/([^/]+)/feed/(feed|rdf|rss|rss2|atom)/?$' => 'index.php?author_name=$matches[1]&feed=$matches[2]',
 	// 'author/([^/]+)/(feed|rdf|rss|rss2|atom)/?$' => 'index.php?author_name=$matches[1]&feed=$matches[2]',
 	public function test_author_feed() {
-		self::factory()->user->create( array( 'user_login' => 'user-a' ) );
 		// Check the long form.
 		$types = array( 'feed', 'rdf', 'rss', 'rss2', 'atom' );
 		foreach ( $types as $type ) {
@@ -607,7 +622,7 @@ public function test_author_feed() {
 	// 'author/([^/]+)/page/?([0-9]{1,})/?$' => 'index.php?author_name=$matches[1]&paged=$matches[2]',
 	public function test_author_paged() {
 		update_option( 'posts_per_page', 2 );
-		$user_id = self::factory()->user->create( array( 'user_login' => 'user-a' ) );
+		$user_id = self::$user_a_id;
 		self::factory()->post->create_many( 3, array( 'post_author' => $user_id ) );
 		$this->go_to( '/author/user-a/page/2/' );
 		$this->assertQueryTrue( 'is_archive', 'is_author', 'is_paged' );
@@ -615,14 +630,13 @@ public function test_author_paged() {
 
 	// 'author/([^/]+)/?$' => 'index.php?author_name=$matches[1]',
 	public function test_author() {
-		$user_id = self::factory()->user->create( array( 'user_login' => 'user-a' ) );
+		$user_id = self::$user_a_id;
 		self::factory()->post->create( array( 'post_author' => $user_id ) );
 		$this->go_to( '/author/user-a/' );
 		$this->assertQueryTrue( 'is_archive', 'is_author' );
 	}
 
 	public function test_author_with_no_posts() {
-		$user_id = self::factory()->user->create( array( 'user_login' => 'user-a' ) );
 		$this->go_to( '/author/user-a/' );
 		$this->assertQueryTrue( 'is_archive', 'is_author' );
 	}
@@ -1122,7 +1136,7 @@ public function test_is_attachment_with_slug_that_begins_with_a_number_that_clas
 	 * @ticket 24674
 	 */
 	public function test_is_author_with_nicename_that_begins_with_a_number_that_clashes_with_another_author_id() {
-		$u1 = self::factory()->user->create();
+		$u1 = self::$user_a_id;
 
 		$u2_name = $u1 . '_user';
 		$u2      = self::factory()->user->create(
@@ -1279,7 +1293,7 @@ public function test_is_page_template_not_singular() {
 		global $wpdb;
 
 		// We need a non-post that shares an ID with a post assigned a template.
-		$user_id = self::factory()->user->create();
+		$user_id = self::$user_a_id;
 		if ( ! get_post( $user_id ) ) {
 			$post_id = self::factory()->post->create( array( 'post_type' => 'post' ) );
 			$wpdb->update( $wpdb->posts, array( 'ID' => $user_id ), array( 'ID' => $post_id ), array( '%d' ) );
@@ -1352,12 +1366,7 @@ public function test_is_attachment_should_not_match_numeric_id_to_post_name_begi
 	 * @ticket 35902
 	 */
 	public function test_is_author_should_not_match_numeric_id_to_nickname_beginning_with_id() {
-		$u1 = self::factory()->user->create(
-			array(
-				'nickname'      => 'Foo',
-				'user_nicename' => 'foo',
-			)
-		);
+		$u1 = self::$user_a_id;
 		$u2 = self::factory()->user->create(
 			array(
 				'nickname'      => "$u1 Foo",
@@ -1375,12 +1384,7 @@ public function test_is_author_should_not_match_numeric_id_to_nickname_beginning
 	 * @ticket 35902
 	 */
 	public function test_is_author_should_not_match_numeric_id_to_user_nicename_beginning_with_id() {
-		$u1 = self::factory()->user->create(
-			array(
-				'nickname'      => 'Foo',
-				'user_nicename' => 'foo',
-			)
-		);
+		$u1 = self::$user_a_id;
 		$u2 = self::factory()->user->create(
 			array(
 				'nickname'      => 'Foo',
diff --git a/tests/phpunit/tests/taxonomy.php b/tests/phpunit/tests/taxonomy.php
index 2a4ee3b560d08..5aefb00651ca8 100644
--- a/tests/phpunit/tests/taxonomy.php
+++ b/tests/phpunit/tests/taxonomy.php
@@ -4,6 +4,18 @@
  * @group taxonomy
  */
 class Tests_Taxonomy extends WP_UnitTestCase {
+
+	/**
+	 * Editor user ID.
+	 *
+	 * @var int $editor_id
+	 */
+	public static $editor_id;
+
+	public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
+		self::$editor_id = $factory->user->create( array( 'role' => 'editor' ) );
+	}
+
 	public function test_get_post_taxonomies() {
 		$this->assertSame( array( 'category', 'post_tag', 'post_format' ), get_object_taxonomies( 'post' ) );
 	}
@@ -1002,7 +1014,7 @@ public function test_edit_post_hierarchical_taxonomy() {
 			)
 		);
 
-		wp_set_current_user( self::factory()->user->create( array( 'role' => 'editor' ) ) );
+		wp_set_current_user( self::$editor_id );
 		$updated_post_id = edit_post(
 			array(
 				'post_ID'   => $post->ID,
@@ -1028,7 +1040,7 @@ public function test_edit_post_hierarchical_taxonomy() {
 	 */
 	public function test_default_term_for_custom_taxonomy() {
 
-		wp_set_current_user( self::factory()->user->create( array( 'role' => 'editor' ) ) );
+		wp_set_current_user( self::$editor_id );
 
 		$tax = 'custom-tax';
 
diff --git a/tests/phpunit/tests/url.php b/tests/phpunit/tests/url.php
index 4768e25b7770a..37ceb69cba192 100644
--- a/tests/phpunit/tests/url.php
+++ b/tests/phpunit/tests/url.php
@@ -7,6 +7,17 @@
  */
 class Tests_URL extends WP_UnitTestCase {
 
+	/**
+	 * Author user ID.
+	 *
+	 * @var int $author_id
+	 */
+	public static $author_id;
+
+	public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
+		self::$author_id = $factory->user->create( array( 'role' => 'author' ) );
+	}
+
 	public function set_up() {
 		parent::set_up();
 		$GLOBALS['pagenow'] = '';
@@ -386,7 +397,7 @@ public function test_get_adjacent_post() {
 	 * @covers ::get_adjacent_post
 	 */
 	public function test_get_adjacent_post_should_return_private_posts_belonging_to_the_current_user() {
-		$u       = self::factory()->user->create( array( 'role' => 'author' ) );
+		$u       = self::$author_id;
 		$old_uid = get_current_user_id();
 		wp_set_current_user( $u );
 
@@ -425,7 +436,7 @@ public function test_get_adjacent_post_should_return_private_posts_belonging_to_
 	 * @covers ::get_adjacent_post
 	 */
 	public function test_get_adjacent_post_should_return_private_posts_belonging_to_other_users_if_the_current_user_can_read_private_posts() {
-		$u1      = self::factory()->user->create( array( 'role' => 'author' ) );
+		$u1      = self::$author_id;
 		$u2      = self::factory()->user->create( array( 'role' => 'administrator' ) );
 		$old_uid = get_current_user_id();
 		wp_set_current_user( $u2 );
@@ -465,7 +476,7 @@ public function test_get_adjacent_post_should_return_private_posts_belonging_to_
 	 * @covers ::get_adjacent_post
 	 */
 	public function test_get_adjacent_post_should_not_return_private_posts_belonging_to_other_users_if_the_current_user_cannot_read_private_posts() {
-		$u1      = self::factory()->user->create( array( 'role' => 'author' ) );
+		$u1      = self::$author_id;
 		$u2      = self::factory()->user->create( array( 'role' => 'author' ) );
 		$old_uid = get_current_user_id();
 		wp_set_current_user( $u2 );
diff --git a/tests/phpunit/tests/user.php b/tests/phpunit/tests/user.php
index 9e1faa2dca3f0..fd3bcc2991abe 100644
--- a/tests/phpunit/tests/user.php
+++ b/tests/phpunit/tests/user.php
@@ -1083,7 +1083,7 @@ public function test_wp_insert_user_with_empty_data() {
 	 * @ticket 35750
 	 */
 	public function test_wp_update_user_should_delete_userslugs_cache() {
-		$u    = self::factory()->user->create();
+		$u    = self::$sub_id;
 		$user = get_userdata( $u );
 
 		wp_update_user(
@@ -1939,11 +1939,7 @@ public function test_edit_user_role_update() {
 		$_GET     = array();
 		$_REQUEST = array();
 
-		$administrator = self::factory()->user->create(
-			array(
-				'role' => 'administrator',
-			)
-		);
+		$administrator = self::$admin_id;
 
 		wp_set_current_user( $administrator );
 
@@ -1957,11 +1953,7 @@ public function test_edit_user_role_update() {
 		$this->assertSame( array( 'administrator' ), get_userdata( $administrator )->roles );
 
 		// Promote an editor to an administrator.
-		$editor = self::factory()->user->create(
-			array(
-				'role' => 'editor',
-			)
-		);
+		$editor = self::$editor_id;
 
 		$_POST['role']     = 'administrator';
 		$_POST['email']    = 'administrator@administrator.test';

From df28a8cfd77e88cbe524bf4c73a174cb4cb691cf Mon Sep 17 00:00:00 2001
From: Luca Tumedei <luca.tumedei@automattic.com>
Date: Wed, 12 Aug 2026 16:34:02 +0200
Subject: [PATCH 2/2] Build/Test Tools: Reduce the bcrypt cost during testing
 in order to speed up tests.

Merges [60298] to the 6.8 branch.

6.8 hashes test user passwords at PHP's default bcrypt cost, which PHP 8.4 raised from 10 to 12. PHPUnit jobs on PHP 8.4 run to a median of 1118 seconds against 820 for PHP 7.2, 7.4 and 8.0, and hit the workflow timeout often enough to trigger an automatic rerun.

The lowest allowable cost in PHP is 4, so 5 is used, which leaves test_wp_check_password_supports_hash_with_reduced_bcrypt_cost() room to reduce the cost by one.

Props johnbillion.
See #63026.
---
 tests/phpunit/includes/abstract-testcase.php | 15 +++++++++++++++
 tests/phpunit/tests/auth.php                 |  5 +----
 2 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/tests/phpunit/includes/abstract-testcase.php b/tests/phpunit/includes/abstract-testcase.php
index f665bdafb17c2..11356cc31c9a0 100644
--- a/tests/phpunit/includes/abstract-testcase.php
+++ b/tests/phpunit/includes/abstract-testcase.php
@@ -136,6 +136,21 @@ public function set_up() {
 		$this->start_transaction();
 		$this->expectDeprecated();
 		add_filter( 'wp_die_handler', array( $this, 'get_wp_die_handler' ) );
+		add_filter( 'wp_hash_password_options', array( $this, 'wp_hash_password_options' ), 1, 2 );
+	}
+
+	/**
+	 * Sets the bcrypt cost option for password hashing during tests.
+	 *
+	 * @param array      $options   The options for password hashing.
+	 * @param string|int $algorithm The algorithm to use for hashing. This is a string in PHP 7.4+ and an integer in PHP 7.3 and earlier.
+	 */
+	public function wp_hash_password_options( array $options, $algorithm ): array {
+		if ( PASSWORD_BCRYPT === $algorithm ) {
+			$options['cost'] = 5;
+		}
+
+		return $options;
 	}
 
 	/**
diff --git a/tests/phpunit/tests/auth.php b/tests/phpunit/tests/auth.php
index 405a8526d05df..a490842ebd1f1 100644
--- a/tests/phpunit/tests/auth.php
+++ b/tests/phpunit/tests/auth.php
@@ -2089,9 +2089,6 @@ private static function set_application_password( string $hash, int $user_id ) {
 	}
 
 	private static function get_default_bcrypt_cost(): int {
-		$hash = password_hash( 'password', PASSWORD_BCRYPT );
-		$info = password_get_info( $hash );
-
-		return $info['options']['cost'];
+		return 5;
 	}
 }