trait RequirementsPageTrait

trait RequirementsPageTrait {
    
    /**
     * Handles the update requirements page.
     */
    protected function updateRequirementsProblem() {
        // Assert a warning is shown on older test environments.
        $links = $this->getSession()
            ->getPage()
            ->findAll('named', [
            'link',
            'try again',
        ]);
        if ($links && version_compare(phpversion(), DRUPAL_MINIMUM_SUPPORTED_PHP) < 0) {
            $this->assertNoText('Errors found');
            $this->assertWarningSummaries([
                'PHP',
            ]);
            $this->clickLink('try again');
            $this->checkForMetaRefresh();
        }
    }
    
    /**
     * Continues installation when the expected warnings are found.
     *
     * This function is no longer called by any core test, but it is retained for
     * use by contrib/custom tests. It is not deprecated, because it remains the
     * recommended function to call for its purpose.
     *
     * @param string[] $expected_warnings
     *   A list of warning summaries to expect on the requirements screen (e.g.
     *   'PHP', 'PHP OPcode caching', etc.). If only the expected warnings
     *   are found, the test will click the "continue anyway" link to go to the
     *   next screen of the installer. If an expected warning is not found, or if
     *   a warning not in the list is present, a fail is raised.
     */
    protected function continueOnExpectedWarnings($expected_warnings = []) {
        $this->assertNoText('Errors found');
        $this->assertWarningSummaries($expected_warnings);
        $this->clickLink('continue anyway');
        $this->checkForMetaRefresh();
    }
    
    /**
     * Assert the given warning summaries are present on the page.
     *
     * If an expected warning is not found, or if a warning not in the list is
     * present, a fail is raised.
     *
     * @param string[] $warning_summaries
     *   A list of warning summaries to expect on the requirements screen (e.g.
     *   'PHP', 'PHP OPcode caching', etc.).
     */
    protected function assertWarningSummaries(array $warning_summaries) {
        // Allow only details elements that are directly after the warning header
        // or each other. There is no guaranteed wrapper we can rely on across
        // distributions. When there are multiple warnings, the selectors will be:
        // - h3#warning+details summary
        // - h3#warning+details+details summary
        // - etc.
        // We add one more selector than expected warnings to confirm that there
        // isn't any other warning before clicking the link.
        // @todo Make this more reliable in
        //   https://www.drupal.org/project/drupal/issues/2927345.
        $selectors = [];
        for ($i = 0; $i <= count($warning_summaries); $i++) {
            $selectors[] = 'h3#warning' . implode('', array_fill(0, $i + 1, '+details')) . ' summary';
        }
        $warning_elements = $this->cssSelect(implode(', ', $selectors));
        // Confirm that there are only the expected warnings.
        $warnings = [];
        foreach ($warning_elements as $warning) {
            $warnings[] = trim($warning->getText());
        }
        $this->assertEquals($warning_summaries, $warnings);
    }

}