composer/src/Composer/Installer/NoopInstaller.php

<?php

/*
 * This file is part of Composer.
 *
 * (c) Nils Adermann <naderman@naderman.de>
 *     Jordi Boggiano <j.boggiano@seld.be>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Composer\Installer;

use Composer\Repository\InstalledRepositoryInterface;
use Composer\Package\PackageInterface;

/**
 * Does not install anything but marks packages installed in the repo
 *
 * Useful for dry runs
 *
 * @author Jordi Boggiano <j.boggiano@seld.be>
 */
class NoopInstaller implements InstallerInterface
{
    /**
     * {@inheritDoc}
     */
    public function supports($packageType)
    {
        return true;
    }

    /**
     * {@inheritDoc}
     */
    public function isInstalled(InstalledRepositoryInterface $repo, PackageInterface $package)
    {
        return $repo->hasPackage($package);
    }

    /**
     * {@inheritDoc}
     */
    public function install(InstalledRepositoryInterface $repo, PackageInterface $package)
    {
        if (!$repo->hasPackage($package)) {
            $repo->addPackage(clone $package);
        }
    }

    /**
     * {@inheritDoc}
     */
    public function update(InstalledRepositoryInterface $repo, PackageInterface $initial, PackageInterface $target)
    {
        if (!$repo->hasPackage($initial)) {
            throw new \InvalidArgumentException('Package is not installed: '.$initial);
        }

        if (!$repo->hasPackage($target)) {
            $repo->addPackage(clone $target);
        }
    }

    /**
     * {@inheritDoc}
     */
    public function uninstall(InstalledRepositoryInterface $repo, PackageInterface $package)
    {
        if (!$repo->hasPackage($package)) {
            // TODO throw exception again here, when update is fixed and we don't have to remove+install (see #125)
            return;
            throw new \InvalidArgumentException('Package is not installed: '.$package);
        }
        $repo->removePackage($package);
    }

    /**
     * {@inheritDoc}
     */
    public function getInstallPath(PackageInterface $package)
    {
        $targetDir = $package->getTargetDir();

        return $package->getPrettyName() . ($targetDir ? '/'.$targetDir : '');
    }
}