Allow PHPUnit 10 and 11 for testing

composer.json

@@ -11,7 +11,7 @@
 	"require-dev": {
 		"squizlabs/php_codesniffer": "^3.5",
 		"php-coveralls/php-coveralls": "~2.0",
-		"phpunit/phpunit": "~7.0||~8.0||~9.0"
+		"phpunit/phpunit": "~7.0||~8.0||~9.0||~10.0||~11.0"
 	},
 	"autoload": {
 		"psr-4": {

tests/MapTest.php

@@ -1247,20 +1247,14 @@ public function testGrepException()
 	{
 		set_error_handler( function( $errno, $str, $file, $line ) { return true; } );
 
-		$this->expectException( \RuntimeException::class );
-		Map::from( [] )->grep( 'b' );
-	}
-
-
-	public function testGrepWarning()
-	{
-		if( method_exists( $this, 'expectWarning' ) ) {
-			$this->expectWarning(); // PHPUnit 8+
-		} else {
-			$this->expectException( \PHPUnit\Framework\Error\Warning::class ); // PHP 7.1
+		try {
+			Map::from( [] )->grep( 'b' );
+			$this->fail( 'An expected RuntimeException has not been raised' );
+		} catch( \RuntimeException $e ) {
+			$this->assertStringContainsString( 'Regular expression error', $e->getMessage() );
+		} finally {
+			restore_error_handler();
 		}
-
-		Map::from( [] )->grep( 'b' );
 	}