diff --git a/modules/features_ui/src/Form/AssignmentBaseForm.php b/modules/features_ui/src/Form/AssignmentBaseForm.php
index 673aee0..c8d4f6b 100644
--- a/modules/features_ui/src/Form/AssignmentBaseForm.php
+++ b/modules/features_ui/src/Form/AssignmentBaseForm.php
@@ -28,7 +28,7 @@ class AssignmentBaseForm extends AssignmentFormBase {
    */
   public function buildForm(array $form, FormStateInterface $form_state, $bundle_name = NULL) {
     $this->currentBundle = $this->assigner->loadBundle($bundle_name);
-    $settings = $this->currentBundle->getAssignmentSettings(self::METHOD_ID);
+    $settings = $this->assigner->getAssignmentSettings(self::METHOD_ID, $this->currentBundle);
 
     // Pass the last argument to limit the select to config entity types that
     // provide bundles for other entity types.
@@ -55,7 +55,7 @@ class AssignmentBaseForm extends AssignmentFormBase {
    */
   public function submitForm(array &$form, FormStateInterface $form_state) {
     // Merge in types selections.
-    $settings = $this->currentBundle->getAssignmentSettings(self::METHOD_ID);
+    $settings = $this->assigner->getAssignmentSettings(self::METHOD_ID, $this->currentBundle);
     $settings['types'] = $form_state->getValue('types');
     $this->currentBundle->setAssignmentSettings(self::METHOD_ID, $settings)->save();
     $this->setRedirect($form_state);
diff --git a/modules/features_ui/src/Form/AssignmentCoreForm.php b/modules/features_ui/src/Form/AssignmentCoreForm.php
index dbd0a98..a094e4f 100644
--- a/modules/features_ui/src/Form/AssignmentCoreForm.php
+++ b/modules/features_ui/src/Form/AssignmentCoreForm.php
@@ -28,7 +28,7 @@ class AssignmentCoreForm extends AssignmentFormBase {
    */
   public function buildForm(array $form, FormStateInterface $form_state, $bundle_name = NULL) {
     $this->currentBundle = $this->assigner->loadBundle($bundle_name);
-    $settings = $this->currentBundle->getAssignmentSettings(self::METHOD_ID);
+    $settings = $this->assigner->getAssignmentSettings(self::METHOD_ID, $this->currentBundle);
 
     $this->setConfigTypeSelect($form, $settings['types']['config'], $this->t('core'));
     $this->setActions($form);
@@ -48,7 +48,7 @@ class AssignmentCoreForm extends AssignmentFormBase {
    */
   public function submitForm(array &$form, FormStateInterface $form_state) {
     // Merge in types selections.
-    $settings = $this->currentBundle->getAssignmentSettings(self::METHOD_ID);
+    $settings = $this->assigner->getAssignmentSettings(self::METHOD_ID, $this->currentBundle);
     $settings['types'] = $form_state->getValue('types');
     $this->currentBundle->setAssignmentSettings(self::METHOD_ID, $settings)->save();
     $this->setRedirect($form_state);
diff --git a/modules/features_ui/src/Form/AssignmentExcludeForm.php b/modules/features_ui/src/Form/AssignmentExcludeForm.php
index 0831342..f29c2dd 100644
--- a/modules/features_ui/src/Form/AssignmentExcludeForm.php
+++ b/modules/features_ui/src/Form/AssignmentExcludeForm.php
@@ -29,7 +29,7 @@ class AssignmentExcludeForm extends AssignmentFormBase {
   public function buildForm(array $form, FormStateInterface $form_state, $bundle_name = NULL) {
     $this->currentBundle = $this->assigner->loadBundle($bundle_name);
 
-    $settings = $this->currentBundle->getAssignmentSettings(self::METHOD_ID);
+    $settings = $this->assigner->getAssignmentSettings(self::METHOD_ID, $this->currentBundle);
     $this->setConfigTypeSelect($form, $settings['types']['config'], $this->t('exclude'));
 
     $module_settings = $settings['module'];
@@ -98,7 +98,7 @@ class AssignmentExcludeForm extends AssignmentFormBase {
    */
   public function submitForm(array &$form, FormStateInterface $form_state) {
     // Merge in selections.
-    $settings = $this->currentBundle->getAssignmentSettings(self::METHOD_ID);
+    $settings = $this->assigner->getAssignmentSettings(self::METHOD_ID, $this->currentBundle);
     $settings = array_merge($settings, [
       'types' => $form_state->getValue('types'),
       'curated' => $form_state->getValue('curated'),
diff --git a/modules/features_ui/src/Form/AssignmentOptionalForm.php b/modules/features_ui/src/Form/AssignmentOptionalForm.php
index 94dba35..4a73c38 100644
--- a/modules/features_ui/src/Form/AssignmentOptionalForm.php
+++ b/modules/features_ui/src/Form/AssignmentOptionalForm.php
@@ -28,7 +28,7 @@ class AssignmentOptionalForm extends AssignmentFormBase {
    */
   public function buildForm(array $form, FormStateInterface $form_state, $bundle_name = NULL) {
     $this->currentBundle = $this->assigner->loadBundle($bundle_name);
-    $settings = $this->currentBundle->getAssignmentSettings(self::METHOD_ID);
+    $settings = $this->assigner->getAssignmentSettings(self::METHOD_ID, $this->currentBundle);
 
     $this->setConfigTypeSelect($form, $settings['types']['config'], $this->t('optional'));
     $this->setActions($form);
@@ -48,7 +48,7 @@ class AssignmentOptionalForm extends AssignmentFormBase {
    */
   public function submitForm(array &$form, FormStateInterface $form_state) {
     // Merge in types selections.
-    $settings = $this->currentBundle->getAssignmentSettings(self::METHOD_ID);
+    $settings = $this->assigner->getAssignmentSettings(self::METHOD_ID, $this->currentBundle);
     $settings['types'] = $form_state->getValue('types');
     $this->currentBundle->setAssignmentSettings(self::METHOD_ID, $settings)->save();
     $this->setRedirect($form_state);
diff --git a/modules/features_ui/src/Form/AssignmentProfileForm.php b/modules/features_ui/src/Form/AssignmentProfileForm.php
index 06db212..f576f55 100644
--- a/modules/features_ui/src/Form/AssignmentProfileForm.php
+++ b/modules/features_ui/src/Form/AssignmentProfileForm.php
@@ -28,7 +28,7 @@ class AssignmentProfileForm extends AssignmentFormBase {
    */
   public function buildForm(array $form, FormStateInterface $form_state, $bundle_name = NULL) {
     $this->currentBundle = $this->assigner->loadBundle($bundle_name);
-    $settings = $this->currentBundle->getAssignmentSettings(self::METHOD_ID);
+    $settings = $this->assigner->getAssignmentSettings(self::METHOD_ID, $this->currentBundle);
 
     $this->setConfigTypeSelect($form, $settings['types']['config'], $this->t('profile'));
 
@@ -76,7 +76,7 @@ class AssignmentProfileForm extends AssignmentFormBase {
    */
   public function submitForm(array &$form, FormStateInterface $form_state) {
     // Merge in selections.
-    $settings = $this->currentBundle->getAssignmentSettings(self::METHOD_ID);
+    $settings = $this->assigner->getAssignmentSettings(self::METHOD_ID, $this->currentBundle);
 
     $settings = array_merge($settings, [
       'curated' => $form_state->getValue('curated'),
diff --git a/modules/features_ui/src/Form/AssignmentSiteForm.php b/modules/features_ui/src/Form/AssignmentSiteForm.php
index 71a4266..46b3e02 100644
--- a/modules/features_ui/src/Form/AssignmentSiteForm.php
+++ b/modules/features_ui/src/Form/AssignmentSiteForm.php
@@ -28,7 +28,7 @@ class AssignmentSiteForm extends AssignmentFormBase {
    */
   public function buildForm(array $form, FormStateInterface $form_state, $bundle_name = NULL) {
     $this->currentBundle = $this->assigner->loadBundle($bundle_name);
-    $settings = $this->currentBundle->getAssignmentSettings(self::METHOD_ID);
+    $settings = $this->assigner->getAssignmentSettings(self::METHOD_ID, $this->currentBundle);
 
     $this->setConfigTypeSelect($form, $settings['types']['config'], $this->t('site'));
     $this->setActions($form);
@@ -48,7 +48,7 @@ class AssignmentSiteForm extends AssignmentFormBase {
    */
   public function submitForm(array &$form, FormStateInterface $form_state) {
     // Merge in types selections.
-    $settings = $this->currentBundle->getAssignmentSettings(self::METHOD_ID);
+    $settings = $this->assigner->getAssignmentSettings(self::METHOD_ID, $this->currentBundle);
     $settings['types'] = $form_state->getValue('types');
     $this->currentBundle->setAssignmentSettings(self::METHOD_ID, $settings)->save();
     $this->setRedirect($form_state);
diff --git a/src/Entity/FeaturesBundle.php b/src/Entity/FeaturesBundle.php
index c06d31f..28c9d8d 100644
--- a/src/Entity/FeaturesBundle.php
+++ b/src/Entity/FeaturesBundle.php
@@ -208,6 +208,12 @@ class FeaturesBundle extends ConfigEntityBase implements FeaturesBundleInterface
     foreach ($this->assignments as $method_id => &$method) {
       $method['enabled'] = in_array($method_id, $assignments);
     }
+
+    // Add any new assignments that we don't yet know about.
+    $new_assignments = array_diff($assignments, array_keys($this->assignments));
+    foreach ($new_assignments as $method_id) {
+      $this->assignments[$method_id] = ['enabled' => TRUE];
+    }
   }
 
   /**
diff --git a/src/FeaturesAssigner.php b/src/FeaturesAssigner.php
index 45ad5ab..d494916 100644
--- a/src/FeaturesAssigner.php
+++ b/src/FeaturesAssigner.php
@@ -414,4 +414,17 @@ class FeaturesAssigner implements FeaturesAssignerInterface {
     }
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function getAssignmentSettings($method_id, $bundle = NULL) {
+    if (empty($bundle)) {
+      $bundle = $this->getBundle();
+    }
+    $settings = $bundle->getAssignmentSettings($method_id);
+    $settings += $this->getAssignmentMethodInstance($method_id)->defaultSettings();
+    $settings += ['enabled' => FALSE, 'weight' => 999];
+    return $settings;
+  }
+
 }
diff --git a/src/FeaturesAssignerInterface.php b/src/FeaturesAssignerInterface.php
index 950f2a8..db5be8d 100644
--- a/src/FeaturesAssignerInterface.php
+++ b/src/FeaturesAssignerInterface.php
@@ -230,4 +230,17 @@ interface FeaturesAssignerInterface {
    */
   public function loadBundle($machine_name = NULL);
 
+  /**
+   * Get the settings for an assignment method.
+   *
+   * @param string $method_id
+   *   The string identifier of the package assignment method.
+   * @param \Drupal\features\FeaturesBundleInterface
+   *   Bundle to get settings from.
+   *
+   * @return array
+   *   The assignment method's settings.
+   */
+  public function getAssignmentSettings($method_id, $bundle = NULL);
+
 }
diff --git a/src/FeaturesAssignmentMethodBase.php b/src/FeaturesAssignmentMethodBase.php
index bf8f6c7..c5898ca 100644
--- a/src/FeaturesAssignmentMethodBase.php
+++ b/src/FeaturesAssignmentMethodBase.php
@@ -86,7 +86,7 @@ abstract class FeaturesAssignmentMethodBase implements FeaturesAssignmentMethodI
    */
   protected function assignPackageByConfigTypes($method_id, $machine_name, $force = FALSE) {
     $current_bundle = $this->assigner->getBundle();
-    $settings = $current_bundle->getAssignmentSettings($method_id);
+    $settings = $this->assigner->getAssignmentSettings($method_id);
     $types = $settings['types']['config'];
 
     $config_collection = $this->featuresManager->getConfigCollection();
@@ -114,7 +114,7 @@ abstract class FeaturesAssignmentMethodBase implements FeaturesAssignmentMethodI
    */
   protected function assignSubdirectoryByConfigTypes($method_id, $subdirectory) {
     $current_bundle = $this->assigner->getBundle();
-    $settings = $current_bundle->getAssignmentSettings($method_id);
+    $settings = $this->assigner->getAssignmentSettings($method_id);
     $types = $settings['types']['config'];
 
     $config_collection = $this->featuresManager->getConfigCollection();
@@ -130,4 +130,11 @@ abstract class FeaturesAssignmentMethodBase implements FeaturesAssignmentMethodI
     $this->featuresManager->setConfigCollection($config_collection);
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function defaultSettings() {
+    return [];
+  }
+
 }
diff --git a/src/FeaturesAssignmentMethodInterface.php b/src/FeaturesAssignmentMethodInterface.php
index a2b90ce..0d272cd 100644
--- a/src/FeaturesAssignmentMethodInterface.php
+++ b/src/FeaturesAssignmentMethodInterface.php
@@ -57,4 +57,12 @@ interface FeaturesAssignmentMethodInterface {
    */
   public function assignPackages($force = FALSE);
 
+  /**
+   * Get the default settings for this assignment.
+   *
+   * @return array
+   *   The settings, not including the keys 'weight' or 'enabled'.
+   */
+  public function defaultSettings();
+
 }
diff --git a/src/Plugin/FeaturesAssignment/FeaturesAssignmentBaseType.php b/src/Plugin/FeaturesAssignment/FeaturesAssignmentBaseType.php
index 6aae549..705f37e 100644
--- a/src/Plugin/FeaturesAssignment/FeaturesAssignmentBaseType.php
+++ b/src/Plugin/FeaturesAssignment/FeaturesAssignmentBaseType.php
@@ -33,7 +33,7 @@ class FeaturesAssignmentBaseType extends FeaturesAssignmentMethodBase {
    */
   public function assignPackages($force = FALSE) {
     $current_bundle = $this->assigner->getBundle();
-    $settings = $current_bundle->getAssignmentSettings(self::METHOD_ID);
+    $settings = $this->assigner->getAssignmentSettings(self::METHOD_ID);
     $config_base_types = $settings['types']['config'];
 
     $config_types = $this->featuresManager->listConfigTypes();
@@ -70,4 +70,16 @@ class FeaturesAssignmentBaseType extends FeaturesAssignmentMethodBase {
     }
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function defaultSettings() {
+    return parent::defaultSettings() + [
+      'types' => [
+        'config' => [],
+        'content' => [],
+      ],
+    ];
+  }
+
 }
diff --git a/src/Plugin/FeaturesAssignment/FeaturesAssignmentCoreType.php b/src/Plugin/FeaturesAssignment/FeaturesAssignmentCoreType.php
index 1239dae..bfefb85 100644
--- a/src/Plugin/FeaturesAssignment/FeaturesAssignmentCoreType.php
+++ b/src/Plugin/FeaturesAssignment/FeaturesAssignmentCoreType.php
@@ -40,4 +40,13 @@ class FeaturesAssignmentCoreType extends FeaturesAssignmentMethodBase {
     $this->assignPackageByConfigTypes(self::METHOD_ID, $machine_name, $force);
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function defaultSettings() {
+    return parent::defaultSettings() + [
+      'types' => ['config' => []],
+    ];
+  }
+
 }
diff --git a/src/Plugin/FeaturesAssignment/FeaturesAssignmentExclude.php b/src/Plugin/FeaturesAssignment/FeaturesAssignmentExclude.php
index 9790b5f..96ef3ea 100644
--- a/src/Plugin/FeaturesAssignment/FeaturesAssignmentExclude.php
+++ b/src/Plugin/FeaturesAssignment/FeaturesAssignmentExclude.php
@@ -32,7 +32,7 @@ class FeaturesAssignmentExclude extends FeaturesAssignmentMethodBase {
    */
   public function assignPackages($force = FALSE) {
     $current_bundle = $this->assigner->getBundle();
-    $settings = $current_bundle->getAssignmentSettings(self::METHOD_ID);
+    $settings = $this->assigner->getAssignmentSettings(self::METHOD_ID);
 
     $config_collection = $this->featuresManager->getConfigCollection();
 
@@ -143,4 +143,19 @@ class FeaturesAssignmentExclude extends FeaturesAssignmentMethodBase {
     $this->featuresManager->setConfigCollection($config_collection);
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function defaultSettings() {
+    return parent::defaultSettings() + [
+      'curated' => FALSE,
+      'module' => [
+        'installed' => FALSE,
+        'profile' => FALSE,
+        'namespace' => FALSE,
+      ],
+      'types' => ['config' => []],
+    ];
+  }
+
 }
diff --git a/src/Plugin/FeaturesAssignment/FeaturesAssignmentOptionalType.php b/src/Plugin/FeaturesAssignment/FeaturesAssignmentOptionalType.php
index 9ce8f3d..5f270c3 100644
--- a/src/Plugin/FeaturesAssignment/FeaturesAssignmentOptionalType.php
+++ b/src/Plugin/FeaturesAssignment/FeaturesAssignmentOptionalType.php
@@ -40,4 +40,13 @@ class FeaturesAssignmentOptionalType extends FeaturesAssignmentMethodBase {
     $this->assignSubdirectoryByConfigTypes(self::METHOD_ID, InstallStorage::CONFIG_OPTIONAL_DIRECTORY);
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function defaultSettings() {
+    return parent::defaultSettings() + [
+      'types' => ['config' => []],
+    ];
+  }
+
 }
diff --git a/src/Plugin/FeaturesAssignment/FeaturesAssignmentProfile.php b/src/Plugin/FeaturesAssignment/FeaturesAssignmentProfile.php
index b63b72d..79017f2 100644
--- a/src/Plugin/FeaturesAssignment/FeaturesAssignmentProfile.php
+++ b/src/Plugin/FeaturesAssignment/FeaturesAssignmentProfile.php
@@ -35,7 +35,7 @@ class FeaturesAssignmentProfile extends FeaturesAssignmentMethodBase {
     $current_bundle = $this->assigner->getBundle();
 
     if ($current_bundle->isProfile()) {
-      $settings = $current_bundle->getAssignmentSettings(self::METHOD_ID);
+      $settings = $this->assigner->getAssignmentSettings(self::METHOD_ID);
 
       // Ensure the profile package exists.
       $profile_name = $current_bundle->getProfileName();
@@ -177,4 +177,18 @@ class FeaturesAssignmentProfile extends FeaturesAssignmentMethodBase {
     ];
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function defaultSettings() {
+    return parent::defaultSettings() + [
+      'types' => ['config' => []],
+      'curated' => FALSE,
+      'standard' => [
+        'files' => FALSE,
+        'dependencies' => FALSE,
+      ],
+    ];
+  }
+
 }
diff --git a/src/Plugin/FeaturesAssignment/FeaturesAssignmentSiteType.php b/src/Plugin/FeaturesAssignment/FeaturesAssignmentSiteType.php
index ec8cdc3..58b5fc5 100644
--- a/src/Plugin/FeaturesAssignment/FeaturesAssignmentSiteType.php
+++ b/src/Plugin/FeaturesAssignment/FeaturesAssignmentSiteType.php
@@ -40,4 +40,13 @@ class FeaturesAssignmentSiteType extends FeaturesAssignmentMethodBase {
     $this->assignPackageByConfigTypes(self::METHOD_ID, $machine_name, $force);
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function defaultSettings() {
+    return parent::defaultSettings() + [
+      'types' => ['config' => []],
+    ];
+  }
+
 }
diff --git a/src/Tests/FeaturesBundleUITest.php b/src/Tests/FeaturesBundleUITest.php
new file mode 100644
index 0000000..29f1513
--- /dev/null
+++ b/src/Tests/FeaturesBundleUITest.php
@@ -0,0 +1,182 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\features\Tests\FeaturesBundleUITest.
+ */
+
+namespace Drupal\features\Tests;
+
+use Drupal\Core\Entity\EntityStorageInterface;
+use Drupal\features\FeaturesBundleInterface;
+use Drupal\simpletest\WebTestBase;
+use Drupal\Core\StringTranslation\StringTranslationTrait;
+
+/**
+ * Tests configuring bundles.
+ *
+ * @group features
+ */
+class FeaturesBundleUITest extends WebTestBase {
+  use StringTranslationTrait;
+
+  /**
+   * @todo Remove the disabled strict config schema checking.
+   */
+  protected $strictConfigSchema = FALSE;
+
+  /**
+   * {@inheritdoc}
+   */
+  public static $modules = ['block', 'features', 'features_ui'];
+
+  /**
+   * The features bundle storage.
+   *
+   * @var \Drupal\Core\Entity\EntityStorageInterface $bundleStorage
+   */
+  protected $bundleStorage;
+
+  /**
+   * {@inheritdoc}
+   */
+  public function setUp() {
+    parent::setUp();
+    $this->bundleStorage = \Drupal::entityTypeManager()->getStorage('features_bundle');
+
+    $admin_user = $this->createUser(['administer site configuration', 'export configuration', 'administer modules']);
+    $this->drupalLogin($admin_user);
+    $this->drupalPlaceBlock('local_actions_block');
+  }
+
+  /**
+   * Get the default features bundle.
+   *
+   * @return \Drupal\features\FeaturesBundleInterface
+   *   The features bundle.
+   */
+  protected function defaultBundle() {
+    return $this->bundleStorage->load('default');
+  }
+
+  /**
+   * Completely remove a features assignment method from the bundle.
+   *
+   * @param string $method_id
+   *   The assignment method ID.
+   */
+  protected function removeAssignment($method_id) {
+    $bundle = $this->defaultBundle();
+    $assignments = $bundle->get('assignments');
+    unset($assignments[$method_id]);
+    $bundle->set('assignments', $assignments);
+    $bundle->save();
+  }
+
+  /**
+   * Tests configuring an assignment.
+   */
+  public function testAssignmentConfigure() {
+    // Check initial values.
+    $settings = $this->defaultBundle()->getAssignmentSettings('exclude');
+    $this->assertTrue(isset($settings['types']['config']['features_bundle']), 'Excluding features_bundle');
+    $this->assertFalse(isset($settings['types']['config']['system_simple']), 'Not excluding system_simple');
+    $this->assertFalse(isset($settings['types']['config']['user_role']), 'Not excluding user_role');
+    $this->assertTrue($settings['curated'], 'Excluding curated items');
+    $this->assertTrue($settings['module']['namespace'], 'Excluding by namespace');
+
+    // Check initial form.
+    $this->drupalGet('admin/config/development/features/bundle/_exclude/default');
+    $this->assertFieldChecked('edit-types-config-features-bundle', 'features_bundle is checked');
+    $this->assertNoFieldChecked('edit-types-config-system-simple', 'system_simple is not checked');
+    $this->assertNoFieldChecked('edit-types-config-user-role', 'user_role is not checked');
+    $this->assertFieldChecked('edit-curated', 'curated is checked');
+    $this->assertFieldChecked('edit-module-namespace', 'namespace is checked');
+
+    // Configure the form.
+    $this->drupalPostForm(NULL, [
+      'types[config][system_simple]' => TRUE,
+      'types[config][user_role]' => FALSE,
+      'curated' => TRUE,
+      'module[namespace]' => FALSE,
+    ], $this->t('Save settings'));
+
+    // Check form results.
+    $this->drupalGet('admin/config/development/features/bundle/_exclude/default');
+    $this->assertFieldChecked('edit-types-config-features-bundle', 'Saved, features_bundle is checked');
+    $this->assertFieldChecked('edit-types-config-system-simple', 'Saved, system_simple is checked');
+    $this->assertNoFieldChecked('edit-types-config-user-role', 'Saved, user_role is not checked');
+    $this->assertFieldChecked('edit-curated', 'Saved, curated is checked');
+    $this->assertNoFieldChecked('edit-module-namespace', 'Saved, namespace is not checked');
+
+    // Check final values.
+    $settings = $this->defaultBundle()->getAssignmentSettings('exclude');
+    $this->assertTrue(isset($settings['types']['config']['features_bundle']), 'Saved, excluding features_bundle');
+    $this->assertTrue(isset($settings['types']['config']['system_simple']), 'Saved, excluding system_simple');
+    $this->assertFalse(isset($settings['types']['config']['user_role']), 'Saved, not excluding user_role');
+    $this->assertTrue($settings['curated'], 'Saved, excluding curated items');
+    $this->assertFalse($settings['module']['namespace'], 'Saved, not excluding by namespace');
+  }
+
+  /**
+   * Tests configuring an assignment that didn't exist before.
+   */
+  public function testNewAssignmentConfigure() {
+    $this->removeAssignment('exclude');
+
+    // Is the method really removed?
+    $settings = $this->defaultBundle()->getAssignmentSettings('exclude');
+    $this->assertIdentical($settings, [], 'No exclude assignment');
+
+    // Can we visit the config page with no settings?
+    $this->drupalGet('admin/config/development/features/bundle/_exclude/default');
+    $this->assertNoFieldChecked('edit-types-config-features-bundle', 'features_bundle is not checked');
+    $this->assertNoFieldChecked('edit-types-config-system-simple', 'system_simple is not checked');
+    $this->assertNoFieldChecked('edit-types-config-user-role', 'user_role is not checked');
+    $this->assertNoFieldChecked('edit-curated', 'curated is not checked');
+    $this->assertNoFieldChecked('edit-module-namespace', 'namespace is not checked');
+
+    // Can we enable the method?
+    $this->drupalGet('admin/config/development/features/bundle');
+    $this->assertNoFieldChecked('edit-enabled-exclude', 'Exclude disabled');
+    $this->drupalPostForm(NULL, [
+      'enabled[exclude]' => TRUE,
+    ], $this->t('Save settings'));
+    $this->assertFieldChecked('edit-enabled-exclude', 'Exclude enabled');
+
+    // Check new settings.
+    $settings = $this->defaultBundle()->getAssignmentSettings('exclude');
+    $this->assertTrue($settings['enabled'], 'Exclude enabled');
+    $this->assertTrue(isset($settings['weight']), 'Exclude has weight');
+    $other_keys = array_diff(array_keys($settings), ['enabled', 'weight']);
+    $this->assertIdentical($other_keys, [], 'Exclude has no other settings');
+
+    // Can we run assignment with no settings?
+    $this->drupalGet('admin/config/development/features');
+
+    // Can we configure the method?
+    $this->drupalPostForm('admin/config/development/features/bundle/_exclude/default', [
+      'types[config][system_simple]' => TRUE,
+      'types[config][user_role]' => FALSE,
+      'curated' => TRUE,
+      'module[namespace]' => FALSE,
+    ], $this->t('Save settings'));
+
+    // Check form results.
+    $this->drupalGet('admin/config/development/features/bundle/_exclude/default');
+    $this->assertNoFieldChecked('edit-types-config-features-bundle', 'Saved, features_bundle is not checked');
+    $this->assertFieldChecked('edit-types-config-system-simple', 'Saved, system_simple is checked');
+    $this->assertNoFieldChecked('edit-types-config-user-role', 'Saved, user_role is not checked');
+    $this->assertFieldChecked('edit-curated', 'Saved, curated is checked');
+    $this->assertNoFieldChecked('edit-module-namespace', 'Saved, namespace is not checked');
+
+    // Check final values.
+    $settings = $this->defaultBundle()->getAssignmentSettings('exclude');
+    $this->assertFalse(isset($settings['types']['config']['features_bundle']), 'Saved, not excluding features_bundle');
+    $this->assertTrue(isset($settings['types']['config']['system_simple']), 'Saved, excluding system_simple');
+    $this->assertFalse(isset($settings['types']['config']['user_role']), 'Saved, not excluding user_role');
+    $this->assertTrue($settings['curated'], 'Saved, excluding curated items');
+    $this->assertFalse($settings['module']['namespace'], 'Saved, not excluding by namespace');
+  }
+
+}
diff --git a/tests/src/Unit/FeaturesBundleTest.php b/tests/src/Unit/FeaturesBundleTest.php
new file mode 100644
index 0000000..a1d8930
--- /dev/null
+++ b/tests/src/Unit/FeaturesBundleTest.php
@@ -0,0 +1,131 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Tests\features\Unit\FeaturesBundleTest.
+ */
+
+namespace Drupal\Tests\features\Unit;
+
+use Drupal\features\Entity\FeaturesBundle;
+use Drupal\Tests\UnitTestCase;
+
+/**
+ * @coversDefaultClass Drupal\features\Entity\FeaturesBundle
+ * @group features
+ */
+class FeaturesBundleTest extends UnitTestCase {
+  /**
+   * Test that assignments can be set and get.
+   */
+  function testAssignmentSetting() {
+    // Create an entity.
+    $settings = [
+      'foo' => [
+        'enabled' => TRUE,
+        'weight' => 0,
+        'my_setting' => 42,
+      ],
+      'bar' => [
+        'enabled' => FALSE,
+        'weight' => 1,
+        'another_setting' => 'value',
+      ],
+    ];
+    $bundle = new FeaturesBundle([
+      'assignments' => $settings,
+    ], 'features_bundle');
+
+    // Get assignments and attributes.
+    $this->assertArrayEquals(
+      $bundle->getEnabledAssignments(),
+      ['foo' => 'foo'],
+      'Can get enabled assignments'
+    );
+    $this->assertArrayEquals(
+      $bundle->getAssignmentWeights(),
+      ['foo' => 0, 'bar' => 1],
+      'Can get assignment weights'
+    );
+    $this->assertArrayEquals(
+      $bundle->getAssignmentSettings('foo'),
+      $settings['foo'],
+      'Can get assignment settings'
+    );
+    $this->assertArrayEquals(
+      $bundle->getAssignmentSettings(),
+      $settings,
+      'Can get all assignment settings'
+    );
+
+    // Change settings.
+    $settings['foo']['my_setting'] = 97;
+    $bundle->setAssignmentSettings('foo', $settings['foo']);
+    $this->assertArrayEquals(
+      $bundle->getAssignmentSettings('foo'),
+      $settings['foo'],
+      'Can change assignment settings'
+    );
+
+    // Change weights.
+    $settings['foo']['weight'] = 1;
+    $settings['bar']['weight'] = 0;
+    $bundle->setAssignmentWeights(['foo' => 1, 'bar' => 0]);
+    $this->assertArrayEquals(
+      $bundle->getAssignmentWeights(),
+      ['foo' => 1, 'bar' => 0],
+      'Can change assignment weights'
+    );
+    $this->assertArrayEquals(
+      $bundle->getAssignmentSettings(),
+      $settings,
+      'Weight changes are reflected in settings'
+    );
+
+    // Enable existing assignment.
+    $settings['bar']['enabled'] = TRUE;
+    $bundle->setEnabledAssignments(['foo', 'bar']);
+    $this->assertArrayEquals(
+      $bundle->getEnabledAssignments(),
+      ['foo' => 'foo', 'bar' => 'bar'],
+      'Can enable assignment'
+    );
+    $this->assertArrayEquals(
+      $bundle->getAssignmentSettings(),
+      $settings,
+      'Enabled assignment status is reflected in settings'
+    );
+
+    // Disable existing assignments.
+    $settings['foo']['enabled'] = FALSE;
+    $settings['bar']['enabled'] = FALSE;
+    $bundle->setEnabledAssignments([]);
+    $this->assertArrayEquals(
+      $bundle->getEnabledAssignments(),
+      [],
+      'Can disable assignments'
+    );
+    $this->assertArrayEquals(
+      $bundle->getAssignmentSettings(),
+      $settings,
+      'Disabled assignment status is reflected in settings'
+    );
+
+    // Enable a new assignment.
+    $settings['foo']['enabled'] = TRUE;
+    $settings['iggy']['enabled'] = TRUE;
+    $bundle->setEnabledAssignments(['foo', 'iggy']);
+    $this->assertArrayEquals(
+      $bundle->getEnabledAssignments(),
+      ['foo' => 'foo', 'iggy' => 'iggy'],
+      'Can enable new assignment'
+    );
+    $this->assertArrayEquals(
+      $bundle->getAssignmentSettings(),
+      $settings,
+      'New enabled assignment status is reflected in settings'
+    );
+
+  }
+
+}