src/Installer/Package/ShopPackageInstaller.php
public function update($packagePath)
    {
        $this->writeUpdatingMessage($this->getPackageTypeDescription());
        $question = 'All files in the following directories will be overwritten:' . PHP_EOL .
                    '- ' . $this->getTargetDirectoryOfShopSource() . PHP_EOL .
                    'Do you want to overwrite them? (y/N) ';

        if ($this->askQuestionIfNotInstalled($question)) {
            $this->writeCopyingMessage();
            $this->copyPackage($packagePath);
            $this->writeDoneMessage();
        } else {
            $this->writeSkippedMessage();
        }
    }
public function update($packagePath)
    {
        $this->writeUpdatingMessage($this->getPackageTypeDescription());
        $question = 'All files in the following directories will be overwritten:' . PHP_EOL .
                    '- ' . $this->getTargetDirectoryOfShopSource() . PHP_EOL .
                    'Do you want to overwrite them? (y/N) ';

        if ($this->askQuestionIfNotInstalled($question)) {
            $this->writeCopyingMessage();
            $this->copyPackage($packagePath);
            $this->writeDoneMessage();
        } else {
            $this->writeSkippedMessage();
        }
    }
Overwrites files in core directories.

@param string $packagePath