Behat-Magento2InitExtension provides access to the magento2 object manager through the BaseFixture class and allows you to change magento config settings temporarly when Behat is running.

Install by adding to your composer.json:

composer require --dev bex/behat-magento2-init

Enable the extension in behat.yml like this:

default:
  extensions:
    Bex\Behat\Magento2InitExtension: ~

You can configure the magento bootstrap file location like this:

default:
  extensions:
    Bex\Behat\Magento2InitExtension:
      magento_bootstrap_path: /path/to/app/bootstrap.php

You can change magento config settings like this:

default:
  extensions:
    Bex\Behat\Magento2InitExtension:
      magento_configs:
        -
          path: 'admin/security/use_form_key'
          value: 0
        -
          path: 'your_module/special_config/awesome_field'
          value: 'somevalue'
          scope_type: 'stores' # allowed values: default, stores, websites; default value: default
          scope_code: 'your_store_code' # the website or store code; default value: null

When you run behat the extension will

• configure the magento2 object manager automatically, so it will be available in all your fixture class which extends the Bex\Behat\Magento2InitExtension\Fixtures\BaseFixture class (see Bex\Behat\Magento2InitExtension\Fixtures\MagentoConfigManager as example).
• change the config values before suit and revert the original config values after suit