diff --git a/modules/facets_range_widget/tests/src/Unit/Plugin/widget/SliderWidgetTest.php b/modules/facets_range_widget/tests/src/Unit/Plugin/widget/SliderWidgetTest.php
index df94c1f..3479404 100644
--- a/modules/facets_range_widget/tests/src/Unit/Plugin/widget/SliderWidgetTest.php
+++ b/modules/facets_range_widget/tests/src/Unit/Plugin/widget/SliderWidgetTest.php
@@ -31,7 +31,7 @@ public function setUp() {
    */
   public function testGetQueryType() {
     $result = $this->widget->getQueryType($this->queryTypes);
-    $this->assertEquals('string', $result);
+    $this->assertEquals(NULL, $result);
   }
 
   /**
diff --git a/src/Entity/Facet.php b/src/Entity/Facet.php
index c90a2f0..330214f 100644
--- a/src/Entity/Facet.php
+++ b/src/Entity/Facet.php
@@ -490,7 +490,7 @@ public function getQueryType() {
     }
 
     // Invalid choice.
-    throw new InvalidQueryTypeException("Invalid query type combination in widget / processors. Widget: {$widgetQueryType}, Processors: " . array_keys($processorQueryTypes) . ".");
+    throw new InvalidQueryTypeException("Invalid query type combination in widget / processors. Widget: {$widgetQueryType}, Processors: " . implode(', ', array_keys($processorQueryTypes)) . ".");
   }
 
   /**
@@ -503,6 +503,7 @@ public function getQueryType() {
    *
    * @return string
    *   The class name of the chose query type.
+   *
    * @throws \Drupal\facets\Exception\InvalidQueryTypeException
    */
   protected function pickQueryType(array $allTypes, $type) {
diff --git a/src/Plugin/facets/query_type/SearchApiDate.php b/src/Plugin/facets/query_type/SearchApiDate.php
index 1e0c769..21d64fd 100644
--- a/src/Plugin/facets/query_type/SearchApiDate.php
+++ b/src/Plugin/facets/query_type/SearchApiDate.php
@@ -406,7 +406,7 @@ protected function getGranularity() {
    * Retrieve configuration: If the date should be displayed relatively.
    *
    * @return bool
-   *  Returns true if the display should be relative, false if it's absolute.
+   *   Returns true if the display should be relative, false if it's absolute.
    */
   protected function getDisplayRelative() {
     return $this->getConfiguration()['display_relative'];
diff --git a/src/Processor/ProcessorInterface.php b/src/Processor/ProcessorInterface.php
index 0617aed..a1b7ec5 100644
--- a/src/Processor/ProcessorInterface.php
+++ b/src/Processor/ProcessorInterface.php
@@ -114,9 +114,9 @@ public function getDescription();
   /**
    * Picks the preferred query type for this widget.
    *
-   * @return string|NULL
+   * @return string|null
    *   The query type machine name to load or NULL to load the default query
-   * type.
+   *   type.
    */
   public function getQueryType();
 
diff --git a/src/Widget/WidgetPluginBase.php b/src/Widget/WidgetPluginBase.php
index b653d49..4331eef 100644
--- a/src/Widget/WidgetPluginBase.php
+++ b/src/Widget/WidgetPluginBase.php
@@ -83,7 +83,7 @@ public function build(FacetInterface $facet) {
    * This allows the following template suggestions:
    *  - facets-item-list--WIDGET_TYPE--FACET_ID
    *  - facets-item-list--WIDGET_TYPE
-   *  - facets-item-list
+   *  - facets-item-list.
    *
    * @param \Drupal\facets\FacetInterface $facet
    *   The facet whose output is being generated.
diff --git a/src/Widget/WidgetPluginInterface.php b/src/Widget/WidgetPluginInterface.php
index 2a819c7..34651c3 100644
--- a/src/Widget/WidgetPluginInterface.php
+++ b/src/Widget/WidgetPluginInterface.php
@@ -25,9 +25,9 @@ public function build(FacetInterface $facet);
   /**
    * Picks the preferred query type for this widget.
    *
-   * @return string|NULL
+   * @return string|null
    *   The query type machine name to load or NULL to load the default query
-   * type.
+   *   type.
    */
   public function getQueryType();
 
diff --git a/tests/facets_custom_widget/src/Plugin/facets/processor/InvalidQT.php b/tests/facets_custom_widget/src/Plugin/facets/processor/InvalidQT.php
index 66f7636..f659823 100644
--- a/tests/facets_custom_widget/src/Plugin/facets/processor/InvalidQT.php
+++ b/tests/facets_custom_widget/src/Plugin/facets/processor/InvalidQT.php
@@ -2,9 +2,6 @@
 
 namespace Drupal\facets_custom_widget\Plugin\facets\processor;
 
-use Drupal\Core\Form\FormStateInterface;
-use Drupal\facets\FacetInterface;
-use Drupal\facets\Processor\PreQueryProcessorInterface;
 use Drupal\facets\Processor\ProcessorPluginBase;
 
 /**
diff --git a/tests/src/Kernel/Entity/FacetFacetSourceTest.php b/tests/src/Kernel/Entity/FacetFacetSourceTest.php
index 72b9b31..27e26bf 100644
--- a/tests/src/Kernel/Entity/FacetFacetSourceTest.php
+++ b/tests/src/Kernel/Entity/FacetFacetSourceTest.php
@@ -175,7 +175,12 @@ public function testQueryTypeJugglingInvalidCombo() {
     $entity->setWidget('numericgranular');
     $entity->setFacetSourceId('search_api:views_page__search_api_test_view__page_1');
     $entity->setFieldIdentifier('name');
-    $entity->addProcessor(['processor_id' => 'test_pre_query', 'weights' => [], 'settings' => []]);
+    $processor = [
+      'processor_id' => 'test_pre_query',
+      'weights' => [],
+      'settings' => [],
+    ];
+    $entity->addProcessor($processor);
 
     $this->setExpectedException(InvalidQueryTypeException::class);
     $entity->getQueryType();
diff --git a/tests/src/Kernel/Plugin/query_type/SearchApiDateTest.php b/tests/src/Kernel/Plugin/query_type/SearchApiDateTest.php
index 5f8a8bb..d78980c 100644
--- a/tests/src/Kernel/Plugin/query_type/SearchApiDateTest.php
+++ b/tests/src/Kernel/Plugin/query_type/SearchApiDateTest.php
@@ -33,31 +33,21 @@ public function setUp() {
    */
   public function testQueryTypeAnd($granularity, $original_results, $grouped_results) {
     $query = new SearchApiQuery([], 'search_api_query', []);
-    $facetReflection = new \ReflectionClass('Drupal\facets\Entity\Facet');
     $facet = new Facet(
       ['query_operator' => 'AND', 'widget' => 'links'],
       'facets_facet'
     );
-    $widget = $this->getMockBuilder('Drupal\facets\Widget\WidgetPluginInterface')
-      ->disableOriginalConstructor()
-      ->getMock();
-    $widget->method('getConfiguration')
-      ->will($this->returnValue([
-        'granularity' => $granularity,
-        'date_display' => '',
-        'display_relative' => FALSE,
-      ]));
-    $widget_instance = $facetReflection->getProperty('widgetInstance');
-    $widget_instance->setAccessible(TRUE);
-    $widget_instance->setValue($facet, $widget);
 
     $query_type = new SearchApiDate(
       [
         'facet' => $facet,
         'query' => $query,
         'results' => $original_results,
+        'granularity' => $granularity,
+        'date_display' => '',
+        'display_relative' => FALSE,
       ],
-      'search_api_string',
+      'search_api_date',
       []
     );
 
diff --git a/tests/src/Unit/Plugin/widget/WidgetTestBase.php b/tests/src/Unit/Plugin/widget/WidgetTestBase.php
index 15bdc3f..8bee2f7 100644
--- a/tests/src/Unit/Plugin/widget/WidgetTestBase.php
+++ b/tests/src/Unit/Plugin/widget/WidgetTestBase.php
@@ -87,7 +87,7 @@ public function testDefaultConfiguration() {
    */
   public function testGetQueryType() {
     $result = $this->widget->getQueryType($this->queryTypes);
-    $this->assertEquals('string', $result);
+    $this->assertEquals(NULL, $result);
   }
 
   /**