WP_Filesystem_Direct::delete( string $file, bool $recursive = false, string|false $type = false )

	public function delete($file, $recursive = false, $type = false) {
		if ( empty( $file ) ) // Some filesystems report this as /, which can cause non-expected recursive deletion of all files in the filesystem.
			return false;
		$file = str_replace( '\\', '/', $file ); // for win32, occasional problems deleting files otherwise

		if ( 'f' == $type || $this->is_file($file) )
			return @unlink($file);
		if ( ! $recursive && $this->is_dir($file) )
			return @rmdir($file);

		// At this point it's a folder, and we're in recursive mode
		$file = trailingslashit($file);
		$filelist = $this->dirlist($file, true);

		$retval = true;
		if ( is_array( $filelist ) ) {
			foreach ( $filelist as $filename => $fileinfo ) {
				if ( ! $this->delete($file . $filename, $recursive, $fileinfo['type']) )
					$retval = false;
			}
		}

		if ( file_exists($file) && ! @rmdir($file) )
			$retval = false;

		return $retval;
	}