Fix schema; add tests.

config/install/lb_direct_add.settings.yml

-use_popover: 0
-trigger_label: 'Add block'
+use_label: 0
+label: 'Add block'

config/schema/lb_direct_add.schema.yml

@@ -2,7 +2,7 @@ lb_direct_add.settings:
   type: config_object
   mapping:
     use_label:
-      type: string
+      type: integer
       label: "How to display the blocks to be added"
     label:
       type: string

tests/src/FunctionalJavascript/LayoutBuilderDirectAddDropbuttonTest.php

+<?php
+
+namespace Drupal\Tests\lb_direct_add\FunctionalJavascript;
+
+/**
+ * Contains test cases for dropbutton functionality.
+ *
+ * @group lb_direct_add
+ */
+class LayoutBuilderDirectAddDropbuttonTest extends LayoutBuilderDirectAddTestBase {
+
+  /**
+   * Test case for dropbutton functionality.
+   */
+  public function testDropbutton() {
+    $this->drupalLogin($this->drupalCreateUser([], NULL, TRUE));
+    $this->drupalGet(static::FIELD_UI_PREFIX . '/display/default/layout');
+
+    $page = $this->getSession()->getPage();
+    $dropbutton_action = $page->findLink('Basic block');
+    static::assertNotNull($dropbutton_action);
+    static::assertTrue($dropbutton_action->isVisible());
+    static::assertEquals(static::BASIC_BLOCK_HREF, $dropbutton_action->getAttribute('href'));
+
+    // Make sure the more option is not visible by default.
+    $dropbutton_more = $page->findLink('More options');
+    static::assertNotNull($dropbutton_more);
+    static::assertFalse($dropbutton_more->isVisible());
+    static::assertEquals(static::CHOOSE_BLOCK_HREF, $dropbutton_more->getAttribute('href'));
+
+    $dropbutton_toggle = $page->findButton('List additional actions');
+    static::assertNotNull($dropbutton_toggle);
+    static::assertTrue($dropbutton_toggle->isVisible());
+
+    $dropbutton_toggle->click();
+    static::assertTrue($dropbutton_more->isVisible());
+
+    $dropbutton_toggle->click();
+    static::assertFalse($dropbutton_more->isVisible());
+
+  }
+
+}

tests/src/FunctionalJavascript/LayoutBuilderDirectAddPopoverTest.php

+<?php
+
+namespace Drupal\Tests\lb_direct_add\FunctionalJavascript;
+
+/**
+ * Contains test cases for popover functionality.
+ *
+ * @group lb_direct_add
+ */
+class LayoutBuilderDirectAddPopoverTest extends LayoutBuilderDirectAddTestBase {
+
+  /**
+   * Test case for popover functionality.
+   */
+  public function testPopover() {
+
+    $this->setUsePopover(1);
+
+    $this->drupalLogin($this->drupalCreateUser([], NULL, TRUE));
+    $this->drupalGet(static::FIELD_UI_PREFIX . '/display/default/layout');
+
+    $page = $this->getSession()->getPage();
+    $add_block = $page->findLink('Add block');
+    static::assertNotNull($add_block);
+    static::assertTrue($add_block->isVisible());
+
+    $this->setTriggerLabel('Add a block');
+
+    $this->drupalGet(static::FIELD_UI_PREFIX . '/display/default/layout');
+    $add_block = $page->findLink('Add block');
+    static::assertNull($add_block);
+
+    $add_block = $page->findLink('Add a block');
+    static::assertNotNull($add_block);
+    static::assertTrue($add_block->isVisible());
+
+    $basic_block = $page->findLink('Basic block');
+    $more = $page->findLink('More options');
+
+    static::assertNotNull($basic_block);
+    static::assertNotNull($more);
+    static::assertEquals(static::BASIC_BLOCK_HREF, $basic_block->getAttribute('href'));
+    static::assertEquals(static::CHOOSE_BLOCK_HREF, $more->getAttribute('href'));
+
+    static::assertFalse($basic_block->isVisible());
+    static::assertFalse($more->isVisible());
+
+    $add_block->click();
+
+    static::assertTrue($basic_block->isVisible());
+    static::assertTrue($more->isVisible());
+
+    $add_block->click();
+
+    static::assertFalse($basic_block->isVisible());
+    static::assertFalse($more->isVisible());
+
+  }
+
+}

tests/src/FunctionalJavascript/LayoutBuilderDirectAddTestBase.php

+<?php
+
+namespace Drupal\Tests\lb_direct_add\FunctionalJavascript;
+
+use Drupal\block_content\Entity\BlockContentType;
+use Drupal\FunctionalJavascriptTests\WebDriverTestBase;
+
+/**
+ * Base class for layout builder direct add javascript tests.
+ */
+abstract class LayoutBuilderDirectAddTestBase extends WebDriverTestBase {
+  /**
+   * Path prefix for the field UI for the test bundle.
+   */
+  protected const FIELD_UI_PREFIX = 'admin/structure/types/manage/bundle_with_section_field';
+
+  /**
+   * Known href attribute for adding a basic block.
+   */
+  protected const BASIC_BLOCK_HREF = '/layout_builder/add/block/defaults/node.bundle_with_section_field.default/0/content/inline_block%3Abasic';
+
+  /**
+   * Known href attribute for adding a block through the core chooser.
+   */
+  protected const CHOOSE_BLOCK_HREF = '/layout_builder/choose/block/defaults/node.bundle_with_section_field.default/0/content';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = [
+    'block_content',
+    'layout_builder',
+    'block',
+    'node',
+    'contextual',
+    'lb_direct_add',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * Sets a new drop button display option.
+   *
+   * @param int $setting
+   *   The new drop button display option.
+   */
+  protected function setUsePopover($setting) {
+    $this->config('lb_direct_add.settings')
+      ->set('use_popover', $setting)
+      ->save();
+  }
+
+  /**
+   * Sets a new trigger label.
+   *
+   * @param string $setting
+   *   The new label.
+   */
+  protected function setTriggerLabel($setting) {
+    $this->config('lb_direct_add.settings')
+      ->set('trigger_label', $setting)
+      ->save();
+  }
+
+  /**
+   * {@inheritdoc}
+   *
+   * Sets up the content types required for lb_direct_add tests.
+   */
+  protected function setUp() {
+    parent::setUp();
+
+    $this->createContentType([
+      'type' => 'bundle_with_section_field',
+      'new_revision' => TRUE,
+    ]);
+
+    /** @var \Drupal\layout_builder\Entity\LayoutEntityDisplayInterface $display */
+    $display = \Drupal::service('entity_display.repository')->getViewDisplay('node', 'bundle_with_section_field');
+    $display->enableLayoutBuilder()->setOverridable()->save();
+
+    $bundle = BlockContentType::create([
+      'id' => 'basic',
+      'label' => 'Basic block',
+      'revision' => 1,
+    ]);
+    $bundle->save();
+    block_content_add_body_field($bundle->id());
+  }
+
+}