class BlockCacheTest

class BlockCacheTest extends BrowserTestBase {
    
    /**
     * {@inheritdoc}
     */
    protected static $modules = [
        'block',
        'block_test',
        'test_page_test',
    ];
    
    /**
     * {@inheritdoc}
     */
    protected $defaultTheme = 'stark';
    
    /**
     * A user with permission to create and edit books and to administer blocks.
     *
     * @var object
     */
    protected $adminUser;
    
    /**
     * An authenticated user to test block caching.
     *
     * @var object
     */
    protected $normalUser;
    
    /**
     * Another authenticated user to test block caching.
     *
     * @var object
     */
    protected $normalUserAlt;
    
    /**
     * The block used by this test.
     *
     * @var \Drupal\block\BlockInterface
     */
    protected $block;
    
    /**
     * {@inheritdoc}
     */
    protected function setUp() : void {
        parent::setUp();
        // Create an admin user, log in and enable test blocks.
        $this->adminUser = $this->drupalCreateUser([
            'administer blocks',
            'access administration pages',
        ]);
        $this->drupalLogin($this->adminUser);
        // Create additional users to test caching modes.
        $this->normalUser = $this->drupalCreateUser();
        $this->normalUserAlt = $this->drupalCreateUser();
        // Sync the roles, since drupalCreateUser() creates separate roles for
        // the same permission sets.
        $this->normalUserAlt->roles = $this->normalUser
            ->getRoles();
        $this->normalUserAlt
            ->save();
        // Enable our test block.
        $this->block = $this->drupalPlaceBlock('test_cache');
    }
    
    /**
     * Tests "user.roles" cache context.
     */
    public function testCachePerRole() : void {
        \Drupal::state()->set('block_test.cache_contexts', [
            'user.roles',
        ]);
        // Enable our test block. Set some content for it to display.
        $current_content = $this->randomMachineName();
        \Drupal::state()->set('block_test.content', $current_content);
        $this->drupalLogin($this->normalUser);
        $this->drupalGet('');
        $this->assertSession()
            ->pageTextContains($current_content);
        // Change the content, but the cached copy should still be served.
        $old_content = $current_content;
        $current_content = $this->randomMachineName();
        \Drupal::state()->set('block_test.content', $current_content);
        $this->drupalGet('');
        $this->assertSession()
            ->pageTextContains($old_content);
        // Clear the cache and verify that the stale data is no longer there.
        Cache::invalidateTags([
            'block_view',
        ]);
        $this->drupalGet('');
        $this->assertSession()
            ->pageTextNotContains($old_content);
        // Fresh block content is displayed after clearing the cache.
        $this->assertSession()
            ->pageTextContains($current_content);
        // Test whether the cached data is served for the correct users.
        $old_content = $current_content;
        $current_content = $this->randomMachineName();
        \Drupal::state()->set('block_test.content', $current_content);
        $this->drupalLogout();
        $this->drupalGet('');
        // Anonymous user does not see content cached per-role for normal user.
        $this->assertSession()
            ->pageTextNotContains($old_content);
        // User with the same roles sees per-role cached content.
        $this->drupalLogin($this->normalUserAlt);
        $this->drupalGet('');
        $this->assertSession()
            ->pageTextContains($old_content);
        // Admin user does not see content cached per-role for normal user.
        $this->drupalLogin($this->adminUser);
        $this->drupalGet('');
        $this->assertSession()
            ->pageTextNotContains($old_content);
        // Block is served from the per-role cache.
        $this->drupalLogin($this->normalUser);
        $this->drupalGet('');
        $this->assertSession()
            ->pageTextContains($old_content);
    }
    
    /**
     * Tests a cacheable block without any additional cache context.
     */
    public function testCachePermissions() : void {
        // user.permissions is a required context, so a user with different
        // permissions will see a different version of the block.
        \Drupal::state()->set('block_test.cache_contexts', []);
        $current_content = $this->randomMachineName();
        \Drupal::state()->set('block_test.content', $current_content);
        $this->drupalGet('');
        $this->assertSession()
            ->pageTextContains($current_content);
        $old_content = $current_content;
        $current_content = $this->randomMachineName();
        \Drupal::state()->set('block_test.content', $current_content);
        // Block content served from cache.
        $this->drupalGet('user');
        $this->assertSession()
            ->pageTextContains($old_content);
        // Block content not served from cache.
        $this->drupalLogout();
        $this->drupalGet('user');
        $this->assertSession()
            ->pageTextContains($current_content);
    }
    
    /**
     * Tests non-cacheable block.
     */
    public function testNoCache() : void {
        \Drupal::state()->set('block_test.cache_max_age', 0);
        $current_content = $this->randomMachineName();
        \Drupal::state()->set('block_test.content', $current_content);
        // If max_age = 0 has no effect, the next request would be cached.
        $this->drupalGet('');
        $this->assertSession()
            ->pageTextContains($current_content);
        // A cached copy should not be served.
        $current_content = $this->randomMachineName();
        \Drupal::state()->set('block_test.content', $current_content);
        $this->drupalGet('');
        // Maximum age of zero prevents blocks from being cached.
        $this->assertSession()
            ->pageTextContains($current_content);
    }
    
    /**
     * Tests "user" cache context.
     */
    public function testCachePerUser() : void {
        \Drupal::state()->set('block_test.cache_contexts', [
            'user',
        ]);
        $current_content = $this->randomMachineName();
        \Drupal::state()->set('block_test.content', $current_content);
        $this->drupalLogin($this->normalUser);
        $this->drupalGet('');
        $this->assertSession()
            ->pageTextContains($current_content);
        $old_content = $current_content;
        $current_content = $this->randomMachineName();
        \Drupal::state()->set('block_test.content', $current_content);
        // Block is served from per-user cache.
        $this->drupalGet('');
        $this->assertSession()
            ->pageTextContains($old_content);
        // Per-user block cache is not served for other users.
        $this->drupalLogin($this->normalUserAlt);
        $this->drupalGet('');
        $this->assertSession()
            ->pageTextContains($current_content);
        // Per-user block cache is persistent.
        $this->drupalLogin($this->normalUser);
        $this->drupalGet('');
        $this->assertSession()
            ->pageTextContains($old_content);
    }
    
    /**
     * Tests "url" cache context.
     */
    public function testCachePerPage() : void {
        \Drupal::state()->set('block_test.cache_contexts', [
            'url',
        ]);
        $current_content = $this->randomMachineName();
        \Drupal::state()->set('block_test.content', $current_content);
        $this->drupalGet('test-page');
        $this->assertSession()
            ->pageTextContains($current_content);
        $old_content = $current_content;
        $current_content = $this->randomMachineName();
        \Drupal::state()->set('block_test.content', $current_content);
        $this->drupalGet('user');
        $this->assertSession()
            ->statusCodeEquals(200);
        // Verify that block content cached for the test page does not show up
        // for the user page.
        $this->assertSession()
            ->pageTextNotContains($old_content);
        $this->drupalGet('test-page');
        $this->assertSession()
            ->statusCodeEquals(200);
        // Verify that the block content is cached for the test page.
        $this->assertSession()
            ->pageTextContains($old_content);
    }

}