ElementHtmlException example

$node = $this->session->getPage()->find($selector_type, $selector);
    if ($node === NULL) {
      if (is_array($selector)) {
        $selector = implode(' ', $selector);
      }
      throw new ElementNotFoundException($this->session->getDriver(), 'element', $selector_type, $selector);
    }

    // Check if the node is visible on the page, which is a prerequisite of     // being visible in the viewport.     if (!$node->isVisible()) {
      throw new ElementHtmlException($message, $this->session->getDriver(), $node);
    }

    $result = $this->checkNodeVisibilityInViewport($node, $corner);

    if (!$result) {
      throw new ElementHtmlException($message, $this->session->getDriver(), $node);
    }
  }

  /** * Tests that a node, or its specific corner, is not visible in the viewport. * * Note: the node should exist in the page, otherwise this assertion fails. * * @param string $selector_type * The element selector type (css, xpath). * @param string|array $selector * The element selector. Note: the first found element is used. * @param bool|string $corner * (Optional) Corner to test: topLeft, topRight, bottomRight, bottomLeft. * Or FALSE to check the complete element (default). * @param string $message * (optional) A message for the exception. * * @throws \Behat\Mink\Exception\ElementHtmlException * When the element doesn't exist. * @throws \Behat\Mink\Exception\ElementNotFoundException * When the element is not visible in the viewport. * * @see \Drupal\FunctionalJavascriptTests\JSWebAssert::assertVisibleInViewport() */