Installing Flex

At the beginning of this chapter, Ryan says the new Sym4 app still works. But I am getting this error when trying to load the homepage (even after removing the two lines from AppKernel.php):

Error: Class AppBundle\Security\LoginFormAuthenticator contains 1 abstract method and must therefore be declared abstract or implement the remaining methods (Symfony\Component\Security\Guard\AuthenticatorInterface::onAuthenticationSuccess)

It looks like something has changed in Guard Authenticator. Is this something that is addressed later in the tutorial? Or should I get it fixed now before trying to install Flex?

Hello, Ryan!
When I installed Flex, it converted my <strong>phpunit.xml.dist</strong> to this:

<?xml version="1.0" encoding="UTF-8"?>

<!-- http://phpunit.de/manual/4.1/en/appendixes.configuration.html -->
<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:noNamespaceSchemaLocation="http://schema.phpunit.de/4.1/phpunit.xsd"
         backupGlobals="false"
         colors="true"
         bootstrap="app/autoload.php"
>
    <php>
        <ini name="error_reporting" value="-1" />

        <!-- ###+ doctrine/doctrine-bundle ### -->
        <!-- Format described at http://docs.doctrine-project.org/projects/doctrine-dbal/en/latest/reference/configuration.html#connecting-using-a-url -->
        <!-- For an SQLite database, use: "sqlite:///%kernel.project_dir%/var/data.db" -->
        <!-- Configure your db driver and server_version in config/packages/doctrine.yaml -->
        <env name="DATABASE_URL" value="mysql://db_user:db_password@127.0.0.1:3306/db_name"/>
        <!-- ###- doctrine/doctrine-bundle ### -->

        <!-- ###+ symfony/swiftmailer-bundle ### -->
        <!-- For Gmail as a transport, use: "gmail://username:password@localhost" -->
        <!-- For a generic SMTP server, use: "smtp://localhost:25?encryption=&auth_mode=" -->
        <!-- Delivery is disabled by default via "null://localhost" -->
        <env name="MAILER_URL" value="null://localhost"/>
        <!-- ###- symfony/swiftmailer-bundle ### -->

        <!-- ###+ symfony/framework-bundle ### -->
        <env name="APP_ENV" value="dev"/>
        <env name="APP_SECRET" value="5f0bab9ed6fbf020425f21cffc2704c9"/>
        <!-- env name="TRUSTED_PROXIES" value="127.0.0.1,127.0.0.2" -->
        <!-- env name="TRUSTED_HOSTS" value="localhost,example.com" -->
        <!-- ###- symfony/framework-bundle ### -->

        <!-- ###+ lexik/jwt-authentication-bundle ### -->
        <!-- Key paths should be relative to the project directory -->
        <env name="JWT_PRIVATE_KEY_PATH" value="config/jwt/private.pem"/>
        <env name="JWT_PUBLIC_KEY_PATH" value="config/jwt/public.pem"/>
        <env name="JWT_PASSPHRASE" value="86c79d44541ebfb81f323ed06a3f0f65"/>
        <!-- ###- lexik/jwt-authentication-bundle ### -->
    </php>

    <testsuites>
        <testsuite name="Project Test Suite">
            <directory>tests</directory>
        </testsuite>
    </testsuites>

    <php>
        <server name="KERNEL_DIR" value="app/" />

        <!-- ###+ doctrine/doctrine-bundle ### -->
        <!-- Format described at http://docs.doctrine-project.org/projects/doctrine-dbal/en/latest/reference/configuration.html#connecting-using-a-url -->
        <!-- For an SQLite database, use: "sqlite:///%kernel.project_dir%/var/data.db" -->
        <!-- Configure your db driver and server_version in config/packages/doctrine.yaml -->
        <env name="DATABASE_URL" value="mysql://db_user:db_password@127.0.0.1:3306/db_name"/>
        <!-- ###- doctrine/doctrine-bundle ### -->

        <!-- ###+ symfony/swiftmailer-bundle ### -->
        <!-- For Gmail as a transport, use: "gmail://username:password@localhost" -->
        <!-- For a generic SMTP server, use: "smtp://localhost:25?encryption=&auth_mode=" -->
        <!-- Delivery is disabled by default via "null://localhost" -->
        <env name="MAILER_URL" value="null://localhost"/>
        <!-- ###- symfony/swiftmailer-bundle ### -->

        <!-- ###+ symfony/framework-bundle ### -->
        <env name="APP_ENV" value="dev"/>
        <env name="APP_SECRET" value="5f0bab9ed6fbf020425f21cffc2704c9"/>
        <!-- env name="TRUSTED_PROXIES" value="127.0.0.1,127.0.0.2" -->
        <!-- env name="TRUSTED_HOSTS" value="localhost,example.com" -->
        <!-- ###- symfony/framework-bundle ### -->

        <!-- ###+ lexik/jwt-authentication-bundle ### -->
        <!-- Key paths should be relative to the project directory -->
        <env name="JWT_PRIVATE_KEY_PATH" value="config/jwt/private.pem"/>
        <env name="JWT_PUBLIC_KEY_PATH" value="config/jwt/public.pem"/>
        <env name="JWT_PASSPHRASE" value="86c79d44541ebfb81f323ed06a3f0f65"/>
        <!-- ###- lexik/jwt-authentication-bundle ### -->
    </php>

    <filter>
        <whitelist>
            <directory>src</directory>
            <exclude>
                <directory>src/*Bundle/Resources</directory>
                <directory>src/*/*Bundle/Resources</directory>
                <directory>src/*/Bundle/*Bundle/Resources</directory>
            </exclude>
        </whitelist>
    </filter>
</phpunit>

However, when starting a new Symfony4 project from scratch and installing PHPUnit in it, I get the following <strong>phpunit.xml.dist</strong>

<?xml version="1.0" encoding="UTF-8"?>

<!-- https://phpunit.de/manual/current/en/appendixes.configuration.html -->
<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:noNamespaceSchemaLocation="http://schema.phpunit.de/6.1/phpunit.xsd"
         backupGlobals="false"
         colors="true"
         bootstrap="vendor/autoload.php"
>
    <php>
        <ini name="error_reporting" value="-1" />
        <env name="KERNEL_CLASS" value="App\Kernel" />
        <env name="APP_ENV" value="test" />
        <env name="APP_DEBUG" value="1" />
        <env name="APP_SECRET" value="s$cretf0rt3st" />
        <env name="SHELL_VERBOSITY" value="-1" />
        <!-- define your env variables for the test env here -->
    </php>

    <testsuites>
        <testsuite name="Project Test Suite">
            <directory>tests/</directory>
        </testsuite>
    </testsuites>

    <filter>
        <whitelist>
            <directory>./src/</directory>
        </whitelist>
    </filter>

    <listeners>
        <listener class="Symfony\Bridge\PhpUnit\SymfonyTestsListener" />
    </listeners>
</phpunit>

My question is why is the top one different from the bottom and why does the top one contain 2 mostly identical sections above and below

    <testsuites>
        <testsuite name="Project Test Suite">
            <directory>tests</directory>
        </testsuite>
    </testsuites>

Thank you!