class Breadcrumb404Test

class Breadcrumb404Test extends BrowserTestBase {
    use BlockCreationTrait;
    
    /**
     * {@inheritdoc}
     */
    protected static $modules = [
        'system',
        'block',
    ];
    
    /**
     * {@inheritdoc}
     */
    protected $defaultTheme = 'stark';
    
    /**
     * Tests that different 404s don't create unnecessary cache entries.
     */
    public function testBreadcrumbOn404Pages() {
        $this->placeBlock('system_breadcrumb_block', [
            'id' => 'breadcrumb',
        ]);
        // Prime the cache first.
        $this->drupalGet('/not-found-1');
        $base_count = count($this->getBreadcrumbCacheEntries());
        $this->drupalGet('/not-found-2');
        $next_count = count($this->getBreadcrumbCacheEntries());
        $this->assertEquals($base_count, $next_count);
        $this->drupalGet('/not-found-3');
        $next_count = count($this->getBreadcrumbCacheEntries());
        $this->assertEquals($base_count, $next_count);
    }
    
    /**
     * Gets the breadcrumb cache entries.
     *
     * @return array
     *   The breadcrumb cache entries.
     */
    protected function getBreadcrumbCacheEntries() {
        $database = \Drupal::database();
        $cache_entries = $database->select('cache_render')
            ->fields('cache_render')
            ->condition('cid', $database->escapeLike('entity_view:block:breadcrumb') . '%', 'LIKE')
            ->execute()
            ->fetchAllAssoc('cid');
        return $cache_entries;
    }

}