diff --git a/core/modules/migrate/tests/src/Kernel/Plugin/MigrationProvidersExistTest.php b/core/modules/migrate/tests/src/Kernel/Plugin/MigrationProvidersExistTest.php
index 6fb43ea16b..517299e4a0 100644
--- a/core/modules/migrate/tests/src/Kernel/Plugin/MigrationProvidersExistTest.php
+++ b/core/modules/migrate/tests/src/Kernel/Plugin/MigrationProvidersExistTest.php
@@ -161,6 +161,7 @@ public function testFieldProvidersExist() {
     $plugin_manager = $this->container->get('plugin.manager.migrate.field');
     $definitions = $plugin_manager->getDefinitions();
     foreach ($definitions as $key => $definition) {
+      $this->assertArrayHasKey($key, $expected_mappings);
       $this->assertEquals($expected_mappings[$key]['source_module'], $definition['source_module']);
       $this->assertEquals($expected_mappings[$key]['destination_module'], $definition['destination_module']);
     }
@@ -197,6 +198,7 @@ public function testFieldProviderMissingRequiredProperty(array $definitions, $mi
    * Data provider for field plugin definitions.
    *
    * @return array
+   *   Array of plugin definitions.
    */
   public function fieldPluginDefinitionsProvider() {
     return [
diff --git a/core/modules/migrate_drupal/src/Annotation/MigrateField.php b/core/modules/migrate_drupal/src/Annotation/MigrateField.php
index 9b032e8713..8225b713f7 100644
--- a/core/modules/migrate_drupal/src/Annotation/MigrateField.php
+++ b/core/modules/migrate_drupal/src/Annotation/MigrateField.php
@@ -55,7 +55,7 @@ public function __construct($values) {
    * Identifies the system providing the data the field plugin will read.
    *
    * The source_module is expected to be the name of a Drupal module that must
-   * must be installed and enabled in the source database.
+   * must be installed in the source database.
    *
    * @var string
    */
@@ -65,7 +65,7 @@ public function __construct($values) {
    * Identifies the system handling the data the destination plugin will write.
    *
    * The destination_module is expected to be the name of a Drupal module on the
-   * destination site that must must be installed and enabled.
+   * destination site that must be installed.
    *
    * @var string
    */
diff --git a/core/modules/migrate_drupal_ui/tests/src/Functional/MigrateUpgradeTestBase.php b/core/modules/migrate_drupal_ui/tests/src/Functional/MigrateUpgradeTestBase.php
index 57533fa0c8..c147e34fcd 100644
--- a/core/modules/migrate_drupal_ui/tests/src/Functional/MigrateUpgradeTestBase.php
+++ b/core/modules/migrate_drupal_ui/tests/src/Functional/MigrateUpgradeTestBase.php
@@ -181,16 +181,17 @@ public function testMigrateUpgrade() {
 
     // Test the available migration paths.
     $all_available = $this->getAvailablePaths();
+    $session = $this->assertSession();
     foreach ($all_available as $available) {
-      $this->assertSession()->elementExists('xpath', '//table[@id="edit-available-module-list-module-list"]//td[text()="' . $available . '"]');
-      $this->assertSession()->elementNotExists('xpath', '//table[@id="edit-missing-module-list"]//td[text()="' . $available . '"]');
+      $session->elementExists('xpath', '//table[@id="edit-available-module-list-module-list"]//td[text()="' . $available . '"]');
+      $session->elementNotExists('xpath', '//table[@id="edit-missing-module-list"]//td[text()="' . $available . '"]');
     }
 
     // Test the missing migration paths.
     $all_missing = $this->getMissingPaths();
     foreach ($all_missing as $missing) {
-      $this->assertSession()->elementExists('xpath', '//table[@id="edit-missing-module-list"]//td[text()="' . $missing . '"]');
-      $this->assertSession()->elementNotExists('xpath', '//table[@id="edit-available-module-list-module-list"]//td[text()="' . $missing . '"]');
+      $session->elementExists('xpath', '//table[@id="edit-missing-module-list"]//td[text()="' . $missing . '"]');
+      $session->elementNotExists('xpath', '//table[@id="edit-available-module-list-module-list"]//td[text()="' . $missing . '"]');
     }
 
     $this->drupalPostForm(NULL, [], t('Perform upgrade'));
@@ -278,7 +279,7 @@ protected function translatePostValues(array $values) {
    * Gets the available upgrade paths.
    *
    * @return string[]
-   *   And array of available upgrade paths.
+   *   An array of available upgrade paths.
    */
   abstract protected function getAvailablePaths();
 
@@ -286,7 +287,7 @@ protected function translatePostValues(array $values) {
    * Gets the missing upgrade paths.
    *
    * @return string[]
-   *   And array of missing upgrade paths.
+   *   An array of missing upgrade paths.
    */
   abstract protected function getMissingPaths();
 
diff --git a/core/modules/migrate_drupal_ui/tests/src/Functional/d6/MigrateUpgrade6Test.php b/core/modules/migrate_drupal_ui/tests/src/Functional/d6/MigrateUpgrade6Test.php
index 4b636357a4..3717606cd8 100644
--- a/core/modules/migrate_drupal_ui/tests/src/Functional/d6/MigrateUpgrade6Test.php
+++ b/core/modules/migrate_drupal_ui/tests/src/Functional/d6/MigrateUpgrade6Test.php
@@ -82,7 +82,7 @@ protected function getEntityCounts() {
   /**
    * {@inheritdoc}
    */
-  public function getAvailablePaths() {
+  protected function getAvailablePaths() {
     return [
       'aggregator',
       'block',
@@ -127,7 +127,7 @@ public function getAvailablePaths() {
   /**
    * {@inheritdoc}
    */
-  public function getMissingPaths() {
+  protected function getMissingPaths() {
     return [
       'date_api',
       'date_timezone',
diff --git a/core/modules/migrate_drupal_ui/tests/src/Functional/d7/MigrateUpgrade7Test.php b/core/modules/migrate_drupal_ui/tests/src/Functional/d7/MigrateUpgrade7Test.php
index 003751bf6f..3cfe4bc6d7 100644
--- a/core/modules/migrate_drupal_ui/tests/src/Functional/d7/MigrateUpgrade7Test.php
+++ b/core/modules/migrate_drupal_ui/tests/src/Functional/d7/MigrateUpgrade7Test.php
@@ -86,7 +86,7 @@ protected function getEntityCounts() {
   /**
    * {@inheritdoc}
    */
-  public function getAvailablePaths() {
+  protected function getAvailablePaths() {
     return [
       'aggregator',
       'block',
@@ -130,7 +130,7 @@ public function getAvailablePaths() {
   /**
    * {@inheritdoc}
    */
-  public function getMissingPaths() {
+  protected function getMissingPaths() {
     return [
       'blog',
       'book',