Magento 2 Module Uninstall – How to Uninstall a Module

Searching the codebase for UninstallInterface gives \Magento\Setup\Model\UninstallCollector.

If you search for UninstallCollector then, you'll find that's used in \Magento\Setup\Console\Command\ModuleUninstallCommand. Particularly relevant:

    $uninstalls = $this->collector->collectUninstall();
    $setupModel = $this->objectManager->get('Magento\Setup\Module\Setup');
    foreach ($modules as $module) {
        if (isset($uninstalls[$module])) {
            $output->writeln("<info>Removing data of $module</info>");
            $uninstalls[$module]->uninstall(
                $setupModel,
                new ModuleContext($this->moduleResource->getDbVersion($module) ?: '')
            );
        } else {
            $output->writeln("<info>No data to clear in $module</info>");
        }
    }

Put together, we can surmise:

1. Your module should contain an Uninstall class at {module}\Setup\Uninstall.php.
2. This class should implement Magento\Framework\Setup\UninstallInterface.
3. This class should have an uninstall method containing any necessary logic.
4. The same objects and methods are available to you as in any setup or upgrade script.

So, here's your skeleton:

<?php

namespace \Custom\Module\Setup;

class Uninstall implements \Magento\Framework\Setup\UninstallInterface
{
    /**
     * Module uninstall code
     *
     * @param \Magento\Framework\Setup\SchemaSetupInterface $setup
     * @param \Magento\Framework\Setup\ModuleContextInterface $context
     * @return void
     */
    public function uninstall(
        \Magento\Framework\Setup\SchemaSetupInterface $setup,
        \Magento\Framework\Setup\ModuleContextInterface $context
    ) {
        $setup->startSetup();

        // Uninstall logic here

        $setup->endSetup();
    }
}

Remove any tables, columns, or data using the appropriate methods. See \Magento\Framework\DB\Adapter\AdapterInterface, available as $setup->getConnection().

If you installed the module manually: remove the folder app/code/<Vendor>/<Module> drop module tables from database remove the config settings.

DELETE FROM core_config_data WHERE path LIKE 'vendor_module/%'

remove the module <Vendor>_<Module> from app/etc/config.php

remove the module <Vendor>_<Module> from table setup_module

DELETE FROM setup_module WHERE module='<Vendor>_<Module>'

Then next follow the command upgrade and compile.

If you installed it via composer:

run this in console:

php bin/magento module:uninstall -r <Vendor>_<Module>

Thanks.