Patch 1

includes/MslsAdmin.php

@@ -239,7 +239,7 @@
 	}
 
 	/**
 	 * Registers the fields in the language_section
 	 *
 	 * Returns the number of added fields
 	 *
@@ -338,7 +338,7 @@
 
 		return count( $map );
 	}
 
 	/**
 	 * Shows the select-form-field 'blog_language'
 	 */
@@ -378,27 +378,17 @@
 	 * Shows the select-form-field 'reference_user'
 	 */
 	public function reference_user(): void {
-		$users = array();
+		$max_users = (int) apply_filters( 'msls_max_reference_users_count', self::MAX_REFERENCE_USERS );
 
-		foreach ( (array) apply_filters( 'msls_reference_users', $this->collection->get_users() ) as $user ) {
-			$users[ $user->ID ] = $user->user_nicename;
-		}
-
-		if ( count( $users ) > self::MAX_REFERENCE_USERS ) {
-			$users = array_slice( $users, 0, self::MAX_REFERENCE_USERS, true );
+		$users_collection = $this->collection->get_users( array( 'ID', 'user_nicename' ), $max_users );
 
-			/* translators: %s: maximum number of users */
-			$format = __(
-				'Multisite Language Switcher: Collection for reference user has been truncated because it exceeded the maximum of %d users. Please, use the hook "msls_reference_users" to filter the result before!',
-				'multisite-language-switcher'
-			);
-
-			// phpcs:ignore WordPress.PHP.DevelopmentFunctions.error_log_trigger_error
-			trigger_error( esc_html( sprintf( $format, strval( self::MAX_REFERENCE_USERS ) ) ) );
-		}
+		$reference_users = (array) apply_filters(
+			'msls_reference_users',
+			wp_list_pluck( $users_collection, 'user_nicename', 'ID' )
+		);
 
         // phpcs:ignore WordPress.Security.EscapeOutput
-		echo ( new Select( 'reference_user', $users, strval( $this->options->reference_user ) ) )->render();
+		echo ( new Select( 'reference_user', $reference_users, strval( $this->options->reference_user ) ) )->render();
 	}
 
 	/**

includes/MslsBlogCollection.php

@@ -301,20 +301,35 @@ public function get_filtered( bool $filter = false ): array {
 	/**
 	 * Gets the registered users of the current blog
 	 *
-	 * @param string     $fields
-	 * @param int|string $number
+	 * @param string|string[] $fields
+	 * @param int             $number
 	 *
 	 * @return array<string, int>
 	 */
-	public function get_users( $fields = 'all', $number = '' ) {
+	public function get_users( $fields = 'all', int $number = 0 ): array {
 		$args = array(
 			'blog_id'     => $this->current_blog_id,
 			'orderby'     => 'registered',
 			'fields'      => $fields,
-			'number'      => $number,
 			'count_total' => false,
 		);
 
+		if ( $number > 1 ) {
+			$args['number'] = $number;
+
+			$user_count = count_users();
+			if ( isset( $user_count['total_users'] ) && $user_count['total_users'] > $number ) {
+				/* translators: %s: maximum number of users */
+				$format = __(
+					'Multisite Language Switcher: The user list has been limited to %d users.',
+					'multisite-language-switcher'
+				);
+
+				// phpcs:ignore WordPress.PHP.DevelopmentFunctions.error_log_trigger_error
+				trigger_error( esc_html( sprintf( $format, strval( $number ) ) ) );
+			}
+		}
+
 		$args = (array) apply_filters( 'msls_get_users', $args );
 
 		return get_users( $args );

tests/phpunit/TestMslsAdmin.php

@@ -116,35 +116,9 @@ public function test_admin_display(): void {
 		$obj->admin_display();
 	}
 
-	public function test_reference_user(): void {
-		$users    = array();
-		$too_much = MslsAdmin::MAX_REFERENCE_USERS + 1;
-		for ( $i = 1; $i <= $too_much; $i++ ) {
-			$users[] = (object) array(
-				'ID'            => $i,
-				'user_nicename' => 'realloc',
-			);
-		}
-
-		$obj = $this->MslsAdminFactory( $users );
-
-		set_error_handler(
-			static function ( $errno, $errstr ) {
-				restore_error_handler();
-				throw new \Exception( $errstr, $errno );
-			},
-			E_ALL
-		);
-
-		$this->expectException( \Exception::class );
-		$this->expectExceptionMessage(
-			'Multisite Language Switcher: Collection for reference user has been truncated because it exceeded the maximum of 100 users. Please, use the hook "msls_reference_users" to filter the result before!'
-		);
-
-		$obj->reference_user();
-	}
-
 	public function test_reference_user_over_max(): void {
+		$users = array( 1 => 'realloc' );
+		Functions\expect( 'wp_list_pluck' )->once()->andReturn( $users );
 		$obj = $this->MslsAdminFactory();
 
 		$this->expectOutputRegex( '/^<select id="reference_user" name="msls\[reference_user\]">.*$/' );

tests/phpunit/TestMslsBlogCollection.php

@@ -12,6 +12,8 @@ final class TestMslsBlogCollection extends MslsUnitTestCase {
 	protected function setUp(): void {
 		parent::setUp(); // TODO: Change the autogenerated stub
 
+		Functions\when( 'count_users' )->justReturn( array( 'total_users' => 3210 ) );
+
 		$options = \Mockery::mock( MslsOptions::class );
 		$options->shouldReceive( 'get_order' )->andReturn( 'description' );
 		$options->shouldReceive( 'is_excluded' )->andReturn( false );
@@ -199,6 +201,27 @@ public function test_get_users(): void {
 		$this->assertIsArray( $obj->get_users() );
 	}
 
+	public function test_get_users_max() {
+		Functions\expect( 'get_site_option' )->once()->andReturn( array() );
+
+		$max_users = 100;
+
+		$obj = new MslsBlogCollection();
+
+		set_error_handler(
+			static function ( $errno, $errstr ) {
+				restore_error_handler();
+				throw new \Exception( $errstr, $errno );
+			},
+			E_ALL
+		);
+
+		$this->expectException( \Exception::class );
+		$this->expectExceptionMessage( "Multisite Language Switcher: The user list has been limited to {$max_users} users." );
+
+		$obj->get_users( 'all', $max_users );
+	}
+
 	public function test_get_current_blog(): void {
 		Functions\expect( 'get_site_option' )->once()->andReturn( array() );