BlockInterfaceTest.php

<?php

namespace Drupal\Tests\block\Kernel;

use Drupal\Core\Block\BlockPluginInterface;
use Drupal\Core\Form\FormState;
use Drupal\KernelTests\KernelTestBase;

/**
 * Tests that the block plugin can work properly without a supporting entity.
 *
 * @group block
 */
class BlockInterfaceTest extends KernelTestBase {
    protected static $modules = [
        'system',
        'block',
        'block_test',
        'user',
    ];
    
    /**
     * Tests configuration and subsequent form() and build() method calls.
     *
     * This test is attempting to test the existing block plugin api and all
     * functionality that is expected to remain consistent. The arrays that are
     * used for comparison can change, but only to include elements that are
     * contained within BlockBase or the plugin being tested. Likely these
     * comparison arrays should get smaller, not larger, as more form/build
     * elements are moved into a more suitably responsible class.
     *
     * Instantiation of the plugin is the primary element being tested here. The
     * subsequent method calls are just attempting to cause a failure if a
     * dependency outside of the plugin configuration is required.
     */
    public function testBlockInterface() {
        $manager = $this->container
            ->get('plugin.manager.block');
        $configuration = [
            'label' => 'Custom Display Message',
        ];
        $expected_configuration = [
            'id' => 'test_block_instantiation',
            'label' => 'Custom Display Message',
            'label_display' => BlockPluginInterface::BLOCK_LABEL_VISIBLE,
            'provider' => 'block_test',
            'display_message' => 'no message set',
        ];
        // Initial configuration of the block at construction time.
        
        /** @var \Drupal\Core\Block\BlockPluginInterface $display_block */
        $display_block = $manager->createInstance('test_block_instantiation', $configuration);
        $this->assertSame($expected_configuration, $display_block->getConfiguration(), 'The block was configured correctly.');
        // Updating an element of the configuration.
        $display_block->setConfigurationValue('display_message', 'My custom display message.');
        $expected_configuration['display_message'] = 'My custom display message.';
        $this->assertSame($expected_configuration, $display_block->getConfiguration(), 'The block configuration was updated correctly.');
        $definition = $display_block->getPluginDefinition();
        $expected_form = [
            'provider' => [
                '#type' => 'value',
                '#value' => 'block_test',
            ],
            'admin_label' => [
                '#type' => 'item',
                '#title' => 'Block description',
                '#plain_text' => $definition['admin_label'],
            ],
            'label' => [
                '#type' => 'textfield',
                '#title' => 'Title',
                '#maxlength' => 255,
                '#default_value' => 'Custom Display Message',
                '#required' => TRUE,
            ],
            'label_display' => [
                '#type' => 'checkbox',
                '#title' => 'Display title',
                '#default_value' => TRUE,
                '#return_value' => 'visible',
            ],
            'context_mapping' => [],
            'display_message' => [
                '#type' => 'textfield',
                '#title' => 'Display message',
                '#default_value' => 'My custom display message.',
            ],
        ];
        $form_state = new FormState();
        // Ensure there are no form elements that do not belong to the plugin.
        $actual_form = $display_block->buildConfigurationForm([], $form_state);
        // Remove the visibility sections, as that just tests condition plugins.
        unset($actual_form['visibility'], $actual_form['visibility_tabs']);
        $this->assertEquals($expected_form, $actual_form, 'Only the expected form elements were present.');
        $expected_build = [
            '#children' => 'My custom display message.',
        ];
        // Ensure the build array is proper.
        $this->assertSame($expected_build, $display_block->build(), 'The plugin returned the appropriate build array.');
        // Ensure the machine name suggestion is correct. In truth, this is actually
        // testing BlockBase's implementation, not the interface itself.
        $this->assertSame('displaymessage', $display_block->getMachineNameSuggestion(), 'The plugin returned the expected machine name suggestion.');
    }

}