class ChainResponsePolicyTest

class ChainResponsePolicyTest extends UnitTestCase {

  /**
   * The chain response policy under test.
   *
   * @var \Drupal\Core\PageCache\ChainResponsePolicy
   */
  protected $policy;

  /**
   * A request object.
   *
   * @var \Symfony\Component\HttpFoundation\Request
   */
  protected $request;

  /**
   * A response object.
   *
   * @var \Symfony\Component\HttpFoundation\Response
   */
  protected $response;

  /**
   * {@inheritdoc}
   */
  protected function setUp() : void {
    parent::setUp();
    $this->policy = new ChainResponsePolicy();
    $this->response = new Response();
    $this->request = new Request();
  }

  /**
   * Asserts that check() returns NULL if the chain is empty.
   *
   * @covers ::check
   */
  public function testEmptyChain() {
    $result = $this->policy
      ->check($this->response, $this->request);
    $this
      ->assertNull($result);
  }

  /**
   * Asserts that check() returns NULL if a rule returns NULL.
   *
   * @covers ::check
   */
  public function testNullRuleChain() {
    $rule = $this
      ->createMock('Drupal\\Core\\PageCache\\ResponsePolicyInterface');
    $rule
      ->expects($this
      ->once())
      ->method('check')
      ->with($this->response, $this->request)
      ->willReturn(NULL);
    $this->policy
      ->addPolicy($rule);
    $result = $this->policy
      ->check($this->response, $this->request);
    $this
      ->assertNull($result);
  }

  /**
   * Asserts that check() throws an exception if a rule returns an invalid value.
   *
   * @dataProvider providerChainExceptionOnInvalidReturnValue
   * @covers ::check
   */
  public function testChainExceptionOnInvalidReturnValue($return_value) {
    $rule = $this
      ->createMock('Drupal\\Core\\PageCache\\ResponsePolicyInterface');
    $rule
      ->expects($this
      ->once())
      ->method('check')
      ->with($this->response, $this->request)
      ->willReturn($return_value);
    $this->policy
      ->addPolicy($rule);
    $this
      ->expectException(\UnexpectedValueException::class);
    $this->policy
      ->check($this->response, $this->request);
  }

  /**
   * Provides test data for testChainExceptionOnInvalidReturnValue.
   *
   * @return array
   *   Test input and expected result.
   */
  public static function providerChainExceptionOnInvalidReturnValue() {
    return [
      [
        FALSE,
      ],
      [
        0,
      ],
      [
        1,
      ],
      [
        TRUE,
      ],
      [
        [
          1,
          2,
          3,
        ],
      ],
      [
        new \stdClass(),
      ],
    ];
  }

  /**
   * Asserts that check() returns immediately when a rule returned DENY.
   */
  public function testStopChainOnFirstDeny() {
    $rule1 = $this
      ->createMock('Drupal\\Core\\PageCache\\ResponsePolicyInterface');
    $rule1
      ->expects($this
      ->once())
      ->method('check')
      ->with($this->response, $this->request);
    $this->policy
      ->addPolicy($rule1);
    $deny_rule = $this
      ->createMock('Drupal\\Core\\PageCache\\ResponsePolicyInterface');
    $deny_rule
      ->expects($this
      ->once())
      ->method('check')
      ->with($this->response, $this->request)
      ->willReturn(ResponsePolicyInterface::DENY);
    $this->policy
      ->addPolicy($deny_rule);
    $ignored_rule = $this
      ->createMock('Drupal\\Core\\PageCache\\ResponsePolicyInterface');
    $ignored_rule
      ->expects($this
      ->never())
      ->method('check');
    $this->policy
      ->addPolicy($ignored_rule);
    $actual_result = $this->policy
      ->check($this->response, $this->request);
    $this
      ->assertSame(ResponsePolicyInterface::DENY, $actual_result);
  }

}