Replace render() call with renderRoot()

Closes #3504763

tests/src/Functional/LoginFormTest.php

+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\openid_connect\Functional;
+
+use Drupal\Tests\BrowserTestBase;
+
+/**
+ * Test the login form openid_connect alterations.
+ *
+ * @group openid_connect
+ */
+class LoginFormTest extends BrowserTestBase {
+
+  use OpenIdClientTestTrait;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = [
+    'openid_connect',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * Confirm a user cannot access another user's connected accounts page.
+   *
+   * @param string $position
+   *   The position setting to test.
+   * @param int $expectedButtonCount
+   *   The expected number of buttons displayed on the login page.
+   *
+   * @dataProvider dataProviderForTestLoginForm
+   */
+  public function testLoginForm(
+    string $position = 'below',
+    int $expectedButtonCount = 2,
+  ): void {
+    $client = $this->createTestClient('test', 'Test OIDC Client');
+
+    $this->updateFormPosition($position);
+    $this->assertEquals($position, \Drupal::configFactory()->get('openid_connect.settings')->get('user_login_display'));
+
+    $this->drupalGet('user/login');
+    $this->assertSession()->statusCodeEquals(200);
+    // Build xpath query getting two form elements by css class.
+    $formSubmitButtons = $this->xpath('//input[contains(@class, "form-submit")]');
+    // Ensure we have the expected amount of form submit buttons.
+    $this->assertCount($expectedButtonCount, $formSubmitButtons);
+
+    // Confirm the button labels are as expected.
+    match($position) {
+      'above', 'replace' => $this->assertEquals(sprintf('Log in with %s', $client->label()), $formSubmitButtons[0]->getValue()),
+      'below' => $this->assertEquals(sprintf('Log in with %s', $client->label()), $formSubmitButtons[1]->getValue()),
+      'hidden' => $this->assertEquals('Log in', $formSubmitButtons[0]->getValue())
+    };
+  }
+
+  /**
+   * Test the OpenID Connect login form `replace` option.
+   */
+  public function testReplaceLoginForm(): void {
+    $client = $this->createTestClient('test', 'Test OIDC Client');
+    $this->updateFormPosition('replace');
+    $this->assertEquals('replace', \Drupal::configFactory()->get('openid_connect.settings')->get('user_login_display'));
+
+    $this->drupalGet('user/login');
+    $this->assertSession()->statusCodeEquals(200);
+    $this->assertSession()->buttonExists(sprintf('Log in with %s', $client->label()));
+    $this->assertSession()->elementNotExists('css', 'form#user-login-form');
+
+    $this->drupalGet('user/login', ['query' => ['showcore' => '1']]);
+    $this->assertSession()->statusCodeEquals(200);
+    $this->assertSession()->elementExists('css', 'form#user-login-form');
+    $this->assertSession()->elementNotExists('css', 'form#openid-connect-login-form');
+  }
+
+  /**
+   * Data provider for the testLoginForm method.
+   *
+   * @return array[]
+   *   Parameters to pass to testDisconnectPermissionDenied.
+   */
+  public static function dataProviderForTestLoginForm(): array {
+    return [
+      'Test the OpenID form is above the normal Drupal login form' => ['above', 2],
+      'Test the OpenID form is below the normal Drupal login form' => ['below', 2],
+      'Test the OpenID form is hidden' => ['hidden', 1],
+      'Test the Drupal login form is replaced with the OpenID form' => ['replace', 1],
+    ];
+  }
+
+  /**
+   * Helper function to update the form position configuration.
+   *
+   * @param string $position
+   *   The position to set the form.
+   */
+  private function updateFormPosition(string $position): void {
+    // Test code goes here.
+    \Drupal::configFactory()->getEditable('openid_connect.settings')->set('user_login_display', $position)->save();
+  }
+
+}