diff --git a/src/Plugin/facets/widget/CheckboxWidget.php b/src/Plugin/facets/widget/CheckboxWidget.php
index 9d0f3ce..d0d51fb 100644
--- a/src/Plugin/facets/widget/CheckboxWidget.php
+++ b/src/Plugin/facets/widget/CheckboxWidget.php
@@ -22,9 +22,16 @@ use Drupal\facets\Widget\WidgetInterface;
 class CheckboxWidget extends LinksWidget {
 
   /**
+   * @var \Drupal\facets\FacetInterface
+   */
+  protected $facet;
+
+  /**
    * {@inheritdoc}
    */
   public function build(FacetInterface $facet) {
+    $this->facet = $facet;
+
     /** @var \Drupal\facets\Result\Result[] $results */
     $results = $facet->getResults();
     $items = [];
@@ -38,7 +45,7 @@ class CheckboxWidget extends LinksWidget {
         $items[] = ['#markup' => $text];
       }
       else {
-        $items[] = $this->buildListItems($result, $facet);
+        $items[] = $this->buildListItems($result);
       }
     }
 
@@ -57,9 +64,12 @@ class CheckboxWidget extends LinksWidget {
     return $build;
   }
 
-  protected function buildListItems(ResultInterface $result, FacetInterface $facet) {
+  /**
+   * {@inheritdoc}
+   */
+  protected function buildListItems(ResultInterface $result) {
     $items = parent::buildListItems($result);
-    $items['#attributes']['id'] = $facet->getUrlAlias() . '-' . $result->getRawValue();
+    $items['#attributes']['id'] = $this->facet->getUrlAlias() . '-' . $result->getRawValue();
     return $items;
   }
 }
diff --git a/tests/src/Unit/Form/CheckboxWidgetFormTest.php b/tests/src/Unit/Form/CheckboxWidgetFormTest.php
deleted file mode 100644
index aead740..0000000
--- a/tests/src/Unit/Form/CheckboxWidgetFormTest.php
+++ /dev/null
@@ -1,140 +0,0 @@
-<?php
-
-namespace Drupal\Tests\facets\Unit\Form;
-
-use Drupal\Core\Form\FormState;
-use Drupal\Core\Url;
-use Drupal\facets\Entity\Facet;
-use Drupal\facets\Form\CheckboxWidgetForm;
-use Drupal\facets\Result\Result;
-use Drupal\Tests\UnitTestCase;
-
-/**
- * Unit test for the checkbox widget form.
- *
- * @group facets
- */
-class CheckboxWidgetFormTest extends UnitTestCase {
-
-  /**
-   * An array containing the results before the processor has ran.
-   *
-   * @var \Drupal\facets\Result\Result[]
-   */
-  protected $originalResults;
-
-  /**
-   * Creates a new processor object for use in the tests.
-   */
-  protected function setUp() {
-    parent::setUp();
-
-    /** @var \Drupal\facets\Result\Result[] $original_results */
-    $original_results = [
-      new Result('llama', 'Llama', 10),
-      new Result('badger', 'Badger', 20),
-      new Result('duck', 'Duck', 15),
-      new Result('alpaca', 'Alpaca', 9),
-    ];
-
-    foreach ($original_results as $original_result) {
-      $original_result->setUrl(new Url('test'));
-    }
-    $original_results[1]->setActiveState(TRUE);
-
-    $this->originalResults = $original_results;
-  }
-
-  /**
-   * Tests widget form with default settings.
-   */
-  public function testDefaultSettings() {
-    $facet = new Facet(['id' => 'zoo_animal'], 'facet');
-    $facet->setResults($this->originalResults);
-    $facet->setFieldIdentifier('zoo_animal');
-
-    $form_state = new FormState();
-    $form_state->addBuildInfo('args', [$facet]);
-    $form = [];
-
-    $widget_form = new CheckboxWidgetForm($facet);
-    $built_form = $widget_form->buildForm($form, $form_state);
-
-    $this->assertInternalType('array', $built_form);
-    $this->assertCount(4, $built_form['zoo_animal']['#options']);
-    $this->assertEquals('checkboxes', $built_form['zoo_animal']['#type']);
-
-    $expected_links = [
-      'llama' => 'Llama',
-      'badger' => 'Badger',
-      'duck' => 'Duck',
-      'alpaca' => 'Alpaca',
-    ];
-    foreach ($expected_links as $index => $value) {
-      $this->assertEquals($value, $built_form['zoo_animal']['#options'][$index]);
-    }
-    $this->assertEquals(array('zoo_animal', 'zoo_animal_submit'), array_keys($built_form));
-  }
-
-  /**
-   * Tests widget form, make sure hiding and showing numbers works.
-   */
-  public function testHideNumbers() {
-    $facet = new Facet([], 'facet');
-    $facet->setResults($this->originalResults);
-    $facet->setFieldIdentifier('zoo__animal');
-    $facet->setWidgetConfigs(['show_numbers' => 0]);
-
-    $form_state = new FormState();
-    $form_state->addBuildInfo('args', [$facet]);
-    $form = [];
-
-    $widget_form = new CheckboxWidgetForm($facet);
-    $built_form = $widget_form->buildForm($form, $form_state);
-
-    $this->assertInternalType('array', $built_form);
-    $this->assertCount(4, $built_form['zoo__animal']['#options']);
-    $expected_links = [
-      'llama' => 'Llama',
-      'badger' => 'Badger',
-      'duck' => 'Duck',
-      'alpaca' => 'Alpaca',
-    ];
-    foreach ($expected_links as $index => $value) {
-      $this->assertEquals($value, $built_form['zoo__animal']['#options'][$index]);
-    }
-
-    // Enable the 'show_numbers' setting again to make sure that the switch
-    // between those settings works.
-    $facet->setWidgetConfigs(['show_numbers' => 1]);
-
-    $built_form = $widget_form->buildForm($form, $form_state);
-    $this->assertInternalType('array', $built_form);
-    $this->assertCount(4, $built_form['zoo__animal']['#options']);
-
-    $expected_links = [
-      'llama' => 'Llama (10)',
-      'badger' => 'Badger (20)',
-      'duck' => 'Duck (15)',
-      'alpaca' => 'Alpaca (9)',
-    ];
-    foreach ($expected_links as $index => $value) {
-      $this->assertEquals($value, $built_form['zoo__animal']['#options'][$index]);
-    }
-  }
-
-  /**
-   * Tests form default methods.
-   */
-  public function testForm() {
-    $facet = new Facet(['id' => 'donkey'], 'facet');
-    $facet->setResults($this->originalResults);
-    $facet->setFieldIdentifier('donkey');
-
-    $form = new CheckboxWidgetForm($facet);
-
-    $this->assertEquals('facets_checkbox_widget', $form->getBaseFormId());
-    $this->assertEquals('facets_checkbox_widget__donkey', $form->getFormId());
-  }
-
-}
diff --git a/tests/src/Unit/Plugin/widget/CheckboxWidgetTest.php b/tests/src/Unit/Plugin/widget/CheckboxWidgetTest.php
index c868d2d..dcd8031 100644
--- a/tests/src/Unit/Plugin/widget/CheckboxWidgetTest.php
+++ b/tests/src/Unit/Plugin/widget/CheckboxWidgetTest.php
@@ -2,12 +2,12 @@
 
 namespace Drupal\Tests\facets\Unit\Plugin\widget;
 
+use Drupal\Component\Render\FormattableMarkup;
 use Drupal\Core\Url;
 use Drupal\facets\Entity\Facet;
 use Drupal\facets\Plugin\facets\widget\CheckboxWidget;
 use Drupal\facets\Result\Result;
 use Drupal\Tests\UnitTestCase;
-use Symfony\Component\DependencyInjection\ContainerBuilder;
 
 /**
  * Unit test for widget.
@@ -49,35 +49,63 @@ class CheckboxWidgetTest extends UnitTestCase {
     }
     $this->originalResults = $original_results;
 
-    $form_builder = $this->getMockBuilder('\Drupal\Core\Form\FormBuilder')
-      ->disableOriginalConstructor()
-      ->getMock();
-    $form_builder->expects($this->once())
-      ->method('getForm')
-      ->willReturn('build');
-
-    $string_translation = $this->getMockBuilder('\Drupal\Core\StringTranslation\TranslationManager')
-      ->disableOriginalConstructor()
-      ->getMock();
-
-    $container_builder = new ContainerBuilder();
-    $container_builder->set('form_builder', $form_builder);
-    $container_builder->set('string_translation', $string_translation);
-    \Drupal::setContainer($container_builder);
-
     $this->widget = new CheckboxWidget();
   }
 
   /**
-   * Tests widget with default settings.
+   * Tests widget without filters.
    */
-  public function testDefaultSettings() {
+  public function testNoFilterResults() {
     $facet = new Facet([], 'facet');
     $facet->setResults($this->originalResults);
-    $facet->setFieldIdentifier('test_field');
+    $facet->setWidgetConfigs(['show_numbers' => 1]);
+
+    $output = $this->widget->build($facet);
+
+    $this->assertInternalType('array', $output);
+    $this->assertCount(4, $output['#items']);
+
+    $this->assertEquals(['js-facets-checkbox-links'], $output['#attributes']['class']);
+
+    $expected_links = [
+      $this->buildLinkAssertion('Llama', 10),
+      $this->buildLinkAssertion('Badger', 20),
+      $this->buildLinkAssertion('Duck', 15),
+      $this->buildLinkAssertion('Alpaca', 9),
+    ];
+    foreach ($expected_links as $index => $value) {
+      $this->assertInternalType('array', $output['#items'][$index]);
+      $this->assertEquals($value, $output['#items'][$index]['#title']);
+      $this->assertInstanceOf(FormattableMarkup::class, $output['#items'][$index]['#title']);
+      $this->assertEquals('link', $output['#items'][$index]['#type']);
+      $this->assertEquals(['facet-item'], $output['#items'][$index]['#wrapper_attributes']['class']);
+    }
+  }
 
-    $built_form = $this->widget->build($facet);
-    $this->assertEquals('build', $built_form);
+  /**
+   * Build a formattable markup object to use in the other tests.
+   *
+   * @param $text
+   *   Text to display.
+   * @param int $count
+   *   Number of results.
+   * @param bool $active
+   *   Link is active.
+   * @param bool $show_numbers
+   *   Numbers are displayed.
+   *
+   * @return \Drupal\Component\Render\FormattableMarkup
+   *   Formattable markup object for link.
+   */
+  private function buildLinkAssertion($text, $count = 0, $active = FALSE, $show_numbers = TRUE) {
+    $text = new FormattableMarkup('@text', ['@text' => $text, '@count' => $count]);
+    if ($show_numbers !== FALSE) {
+      $text->string .= ' <span class="facet-count">(@count)</span>';
+    }
+    if ($active) {
+      $text->string = '<span class="facet-deactivate">(-)</span> ' . $text->string;
+    }
+    return $text;
   }
 
 }
diff --git a/tests/src/Unit/Plugin/widget/LinksWidgetTest.php b/tests/src/Unit/Plugin/widget/LinksWidgetTest.php
index ae2b6f4..075bcb3 100644
--- a/tests/src/Unit/Plugin/widget/LinksWidgetTest.php
+++ b/tests/src/Unit/Plugin/widget/LinksWidgetTest.php
@@ -237,4 +237,5 @@ class LinksWidgetTest extends UnitTestCase {
     }
     return $text;
   }
+
 }