Issue #2825712 by Utkarsh_33, lauriii, bnjmnm, tstoeckler, idebr, BramDriesen,...

Issue #2825712 by Utkarsh_33, lauriii, bnjmnm, tstoeckler, idebr, BramDriesen, Lendude, srishtiiee: The allowed values storage setting of list fields should be required

(cherry picked from commit 18432dac)

core/modules/options/src/Plugin/Field/FieldType/ListFloatItem.php

@@ -77,6 +77,7 @@ protected static function extractAllowedValues($string, $has_data) {
 
       return array_combine($keys, $labels);
     }
+    return $values;
   }
 
   /**

core/modules/options/src/Plugin/Field/FieldType/ListItemBase.php

@@ -98,6 +98,7 @@ public function storageSettingsForm(array &$form, FormStateInterface $form_state
       '#field_name' => $this->getFieldDefinition()->getName(),
       '#entity_type' => $this->getEntity()->getEntityTypeId(),
       '#allowed_values' => $allowed_values,
+      '#required' => TRUE,
     ];
 
     $element['allowed_values']['#description'] = $this->allowedValuesDescription();

core/modules/options/tests/src/Functional/OptionsFieldUITest.php

@@ -384,4 +384,27 @@ public function testNodeDisplay() {
     }
   }
 
+  /**
+   * Confirms the allowed value list is a required field.
+   */
+  public function testRequiredPropertyForAllowedValuesList() {
+    $field_types = [
+      'list_float',
+      'list_string',
+      'list_integer',
+    ];
+
+    foreach ($field_types as $field_type) {
+      $this->fieldName = "field_options_$field_type";
+      $this->createOptionsField($field_type);
+
+      // Try to proceed without entering any value.
+      $this->drupalGet($this->adminPath);
+      $this->submitForm([], 'Save field settings');
+
+      // Confirmation message that this is a required field.
+      $this->assertSession()->pageTextContains('Allowed values list field is required.');
+    }
+  }
+
 }