class MockBlockManager

class MockBlockManager extends PluginManagerBase {
    public function __construct() {
        // Create the object that can be used to return definitions for all the
        // plugins available for this type. Most real plugin managers use a richer
        // discovery implementation, but StaticDiscovery lets us add some simple
        // mock plugins for unit testing.
        $this->discovery = new StaticDiscovery();
        // Derivative plugins are plugins that are derived from a base plugin
        // definition and some site configuration (examples below). To allow for
        // such plugins, we add the DerivativeDiscoveryDecorator to our discovery
        // object.
        $this->discovery = new DerivativeDiscoveryDecorator($this->discovery);
        // The plugin definitions that follow are based on work that is in progress
        // for the Drupal 8 Blocks and Layouts initiative
        // (http://groups.drupal.org/node/213563). As stated above, we set
        // definitions here, because this is for unit testing. Real plugin managers
        // use a discovery implementation that allows for any module to add new
        // plugins to the system.
        // A simple plugin: the user login block.
        $this->discovery
            ->setDefinition('user_login', [
            'id' => 'user_login',
            'label' => t('User login'),
            'class' => 'Drupal\\plugin_test\\Plugin\\plugin_test\\mock_block\\MockUserLoginBlock',
        ]);
        // A plugin that requires derivatives: the menu block plugin. We do not want
        // a generic "Menu" block showing up in the Block administration UI.
        // Instead, we want a block for each menu, but the number of menus in the
        // system and each one's title is user configurable. The
        // MockMenuBlockDeriver class ensures that only derivatives, and not the
        // base plugin, are available to the system.
        $this->discovery
            ->setDefinition('menu', [
            'id' => 'menu',
            'class' => 'Drupal\\plugin_test\\Plugin\\plugin_test\\mock_block\\MockMenuBlock',
            'deriver' => 'Drupal\\plugin_test\\Plugin\\plugin_test\\mock_block\\MockMenuBlockDeriver',
        ]);
        // A plugin defining itself as a derivative.
        $this->discovery
            ->setDefinition('menu:foo', [
            'id' => 'menu',
            'label' => t('Base label'),
            'class' => 'Drupal\\plugin_test\\Plugin\\plugin_test\\mock_block\\MockMenuBlock',
        ]);
        // A block plugin that can optionally be derived: the layout block plugin.
        // A layout is a special kind of block into which other blocks can be
        // placed. We want both a generic "Layout" block available in the Block
        // administration UI as well as additional user-created custom layouts. The
        // MockLayoutBlockDeriver class ensures that both the base plugin and the
        // derivatives are available to the system.
        $this->discovery
            ->setDefinition('layout', [
            'id' => 'layout',
            'label' => t('Layout'),
            'class' => 'Drupal\\plugin_test\\Plugin\\plugin_test\\mock_block\\MockLayoutBlock',
            'deriver' => 'Drupal\\plugin_test\\Plugin\\plugin_test\\mock_block\\MockLayoutBlockDeriver',
        ]);
        // A block plugin that requires context to function. This block requires a
        // user object in order to return the user name from the getTitle() method.
        $this->discovery
            ->setDefinition('user_name', [
            'id' => 'user_name',
            'label' => t('User name'),
            'class' => 'Drupal\\plugin_test\\Plugin\\plugin_test\\mock_block\\MockUserNameBlock',
            'context_definitions' => [
                'user' => $this->createContextDefinition('entity:user', t('User')),
            ],
        ]);
        // An optional context version of the previous block plugin.
        $this->discovery
            ->setDefinition('user_name_optional', [
            'id' => 'user_name_optional',
            'label' => t('User name optional'),
            'class' => 'Drupal\\plugin_test\\Plugin\\plugin_test\\mock_block\\MockUserNameBlock',
            'context_definitions' => [
                'user' => $this->createContextDefinition('entity:user', t('User'), FALSE),
            ],
        ]);
        // A block plugin that requires a typed data string context to function.
        $this->discovery
            ->setDefinition('string_context', [
            'id' => 'string_context',
            'label' => t('String typed data'),
            'class' => 'Drupal\\plugin_test\\Plugin\\plugin_test\\mock_block\\TypedDataStringBlock',
        ]);
        // A complex context plugin that requires both a user and node for context.
        $this->discovery
            ->setDefinition('complex_context', [
            'id' => 'complex_context',
            'label' => t('Complex context'),
            'class' => 'Drupal\\plugin_test\\Plugin\\plugin_test\\mock_block\\MockComplexContextBlock',
            'context_definitions' => [
                'user' => $this->createContextDefinition('entity:user', t('User')),
                'node' => $this->createContextDefinition('entity:node', t('Node')),
            ],
        ]);
        // In addition to finding all of the plugins available for a type, a plugin
        // type must also be able to create instances of that plugin. For example, a
        // specific instance of a "Main menu" menu block, configured to show just
        // the top-level of links. To handle plugin instantiation, plugin managers
        // can use one of the factory classes included with the plugin system, or
        // create their own. ReflectionFactory is a general purpose, flexible
        // factory suitable for many kinds of plugin types. Factories need access to
        // the plugin definitions (e.g., since that's where the plugin's class is
        // specified), so we provide it the discovery object.
        $this->factory = new ReflectionFactory($this->discovery);
    }
    
    /**
     * Creates a new context definition with a label that is cast to string.
     *
     * @param string $data_type
     *   The required data type.
     * @param mixed|string|null $label
     *   The label of this context definition for the UI.
     * @param bool $required
     *   Whether the context definition is required.
     *
     * @return \Drupal\Core\Plugin\Context\ContextDefinition
     */
    protected function createContextDefinition($data_type, $label, $required = TRUE) {
        // We cast the label to string for testing purposes only, as it may be
        // a TranslatableMarkup and we will do assertEqual() checks on arrays that
        // include ContextDefinition objects, and var_export() has problems
        // printing TranslatableMarkup objects.
        $class = ContextDefinition::class;
        if (strpos($data_type, 'entity:') === 0) {
            $class = EntityContextDefinition::class;
        }
        return new $class($data_type, (string) $label, $required);
    }

}