versions.php

<?php
    /**
     * Returns sorted array of all versions reachable from $version
     * @param string $version
     * @return string[]
     */
    public function getReachableVersions($version)
    {
        $migrations = $this->migration_manager->getMigrations();
        $versions = array_keys($migrations);
        $index = array_search($version, $versions);
        if ($index === false) {
            throw new OutOfBoundsException("Version not found: $version");
        }
        $upgrades = array_slice($versions, $index + 1);
        $downgrades = [];
        for ($min = $index; $min > 0 && $migrations[$versions[$min]]->canRollback(); $min--) {
            $downgrades[] = $versions[$min - 1];
        }
        return [$downgrades, $upgrades];
    }