FormStoragePageCacheTest.php

<?php

namespace Drupal\Tests\system\Functional\Form;

use Drupal\Tests\BrowserTestBase;

/**
 * Tests form storage from cached pages.
 *
 * @group Form
 */
class FormStoragePageCacheTest extends BrowserTestBase {
    
    /**
     * @var array
     */
    public static $modules = [
        'form_test',
    ];
    
    /**
     * {@inheritdoc}
     */
    protected $defaultTheme = 'stark';
    
    /**
     * {@inheritdoc}
     */
    protected function setUp() {
        parent::setUp();
        $config = $this->config('system.performance');
        $config->set('cache.page.max_age', 300);
        $config->save();
    }
    
    /**
     * Return the build id of the current form.
     */
    protected function getFormBuildId() {
        $build_id_fields = $this->xpath('//input[@name="form_build_id"]');
        $this->assertCount(1, $build_id_fields, 'One form build id field on the page');
        return (string) $build_id_fields[0]->getAttribute('value');
    }
    
    /**
     * Build-id is regenerated when validating cached form.
     */
    public function testValidateFormStorageOnCachedPage() {
        $this->drupalGet('form-test/form-storage-page-cache');
        $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'MISS', 'Page was not cached.');
        $this->assertText('No old build id', 'No old build id on the page');
        $build_id_initial = $this->getFormBuildId();
        // Trigger validation error by submitting an empty title.
        $edit = [
            'title' => '',
        ];
        $this->drupalPostForm(NULL, $edit, 'Save');
        $this->assertText('No old build id', 'No old build id on the page');
        $build_id_first_validation = $this->getFormBuildId();
        $this->assertNotEqual($build_id_initial, $build_id_first_validation, 'Build id changes when form validation fails');
        // Trigger validation error by again submitting an empty title.
        $edit = [
            'title' => '',
        ];
        $this->drupalPostForm(NULL, $edit, 'Save');
        $this->assertText('No old build id', 'No old build id on the page');
        $build_id_second_validation = $this->getFormBuildId();
        $this->assertEqual($build_id_first_validation, $build_id_second_validation, 'Build id remains the same when form validation fails subsequently');
        // Repeat the test sequence but this time with a page loaded from the cache.
        $this->drupalGet('form-test/form-storage-page-cache');
        $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'HIT', 'Page was cached.');
        $this->assertText('No old build id', 'No old build id on the page');
        $build_id_from_cache_initial = $this->getFormBuildId();
        $this->assertEqual($build_id_initial, $build_id_from_cache_initial, 'Build id is the same as on the first request');
        // Trigger validation error by submitting an empty title.
        $edit = [
            'title' => '',
        ];
        $this->drupalPostForm(NULL, $edit, 'Save');
        $this->assertText('No old build id', 'No old build id on the page');
        $build_id_from_cache_first_validation = $this->getFormBuildId();
        $this->assertNotEqual($build_id_initial, $build_id_from_cache_first_validation, 'Build id changes when form validation fails');
        $this->assertNotEqual($build_id_first_validation, $build_id_from_cache_first_validation, 'Build id from first user is not reused');
        // Trigger validation error by again submitting an empty title.
        $edit = [
            'title' => '',
        ];
        $this->drupalPostForm(NULL, $edit, 'Save');
        $this->assertText('No old build id', 'No old build id on the page');
        $build_id_from_cache_second_validation = $this->getFormBuildId();
        $this->assertEqual($build_id_from_cache_first_validation, $build_id_from_cache_second_validation, 'Build id remains the same when form validation fails subsequently');
    }
    
    /**
     * Build-id is regenerated when rebuilding cached form.
     */
    public function testRebuildFormStorageOnCachedPage() {
        $this->drupalGet('form-test/form-storage-page-cache');
        $this->assertEqual($this->drupalGetHeader('X-Drupal-Cache'), 'MISS', 'Page was not cached.');
        $this->assertText('No old build id', 'No old build id on the page');
        $build_id_initial = $this->getFormBuildId();
        // Trigger rebuild, should regenerate build id. When a submit handler
        // triggers a rebuild, the form is built twice in the same POST request,
        // and during the second build, there is an old build ID, but because the
        // form is not cached during the initial GET request, it is different from
        // that initial build ID.
        $edit = [
            'title' => 'something',
        ];
        $this->drupalPostForm(NULL, $edit, 'Rebuild');
        $this->assertNoText('No old build id', 'There is no old build id on the page.');
        $this->assertNoText($build_id_initial, 'The old build id is not the initial build id.');
        $build_id_first_rebuild = $this->getFormBuildId();
        $this->assertNotEqual($build_id_initial, $build_id_first_rebuild, 'Build id changes on first rebuild.');
        // Trigger subsequent rebuild, should regenerate the build id again.
        $edit = [
            'title' => 'something',
        ];
        $this->drupalPostForm(NULL, $edit, 'Rebuild');
        $this->assertText($build_id_first_rebuild, 'First build id as old build id on the page');
        $build_id_second_rebuild = $this->getFormBuildId();
        $this->assertNotEqual($build_id_first_rebuild, $build_id_second_rebuild, 'Build id changes on second rebuild.');
    }

}