diff --git a/modules/commerce/src/Plugin/migrate/field/commerce1/CommerceProductReference.php b/modules/commerce/src/Plugin/migrate/field/commerce1/CommerceProductReference.php
index 37d2e4d..32eb9da 100644
--- a/modules/commerce/src/Plugin/migrate/field/commerce1/CommerceProductReference.php
+++ b/modules/commerce/src/Plugin/migrate/field/commerce1/CommerceProductReference.php
@@ -49,4 +49,5 @@ class CommerceProductReference extends FieldPluginBase {
       'commerce_product_reference_autocomplete' => 'entity_reference_autocomplete',
     ];
   }
+
 }
diff --git a/modules/commerce/src/Plugin/migrate/source/commerce1/LineItem.php b/modules/commerce/src/Plugin/migrate/source/commerce1/LineItem.php
index fe2ce0e..ea4f56c 100644
--- a/modules/commerce/src/Plugin/migrate/source/commerce1/LineItem.php
+++ b/modules/commerce/src/Plugin/migrate/source/commerce1/LineItem.php
@@ -35,15 +35,15 @@ class LineItem extends FieldableEntity {
    */
   public function fields() {
     return [
-      'line_item_id' => t('Line Item ID'),
-      'title' => t('Product title'),
-      'order_id' => t('Order ID'),
-      'type' => t('Type'),
-      'line_item_label' => t('Line Item Label'),
-      'quantity' => t('Quantity'),
-      'created' => t('Created'),
-      'changed' => t('Changes'),
-      'data' => t('Data'),
+      'line_item_id' => $this->t('Line Item ID'),
+      'title' => $this->t('Product title'),
+      'order_id' => $this->t('Order ID'),
+      'type' => $this->t('Type'),
+      'line_item_label' => $this->t('Line Item Label'),
+      'quantity' => $this->t('Quantity'),
+      'created' => $this->t('Created'),
+      'changed' => $this->t('Changes'),
+      'data' => $this->t('Data'),
     ];
   }
 
diff --git a/modules/commerce/src/Plugin/migrate/source/commerce1/Message.php b/modules/commerce/src/Plugin/migrate/source/commerce1/Message.php
index 61611d6..c0d2a0f 100644
--- a/modules/commerce/src/Plugin/migrate/source/commerce1/Message.php
+++ b/modules/commerce/src/Plugin/migrate/source/commerce1/Message.php
@@ -45,15 +45,15 @@ class Message extends FieldableEntity {
    */
   public function fields() {
     return [
-      'mid' => t('Message ID'),
-      'type' => t('Message type'),
-      'arguments' => t('Arguments'),
-      'uid' => t('UID'),
-      'timestamp' => t('Message timestamp'),
-      'language' => t('Language'),
-      'target_id' => t('Target ID'),
-      'name' => t('Message type name'),
-      'category' => t('Message category'),
+      'mid' => $this->t('Message ID'),
+      'type' => $this->t('Message type'),
+      'arguments' => $this->t('Arguments'),
+      'uid' => $this->t('UID'),
+      'timestamp' => $this->t('Message timestamp'),
+      'language' => $this->t('Language'),
+      'target_id' => $this->t('Target ID'),
+      'name' => $this->t('Message type name'),
+      'category' => $this->t('Message category'),
     ];
   }
 
diff --git a/modules/commerce/src/Plugin/migrate/source/commerce1/Order.php b/modules/commerce/src/Plugin/migrate/source/commerce1/Order.php
index 37564be..89df6b8 100644
--- a/modules/commerce/src/Plugin/migrate/source/commerce1/Order.php
+++ b/modules/commerce/src/Plugin/migrate/source/commerce1/Order.php
@@ -58,19 +58,19 @@ class Order extends FieldableEntity {
    */
   public function fields() {
     return [
-      'order_id' => t('Order ID'),
-      'commerce_order_total' => t('Order Number'),
-      'revision_id' => t('Revision ID'),
-      'type' => t('Type'),
-      'uid' => t('User ID'),
-      'mail' => t('Email'),
-      'status' => t('Status'),
-      'created' => t('Created'),
-      'changed' => t('Changed'),
-      'default_store_id' => t('Default store id'),
-      'refresh_state' => t('Order refresh state'),
-      'hostname' => t('Hostname'),
-      'data' => t('Data'),
+      'order_id' => $this->t('Order ID'),
+      'commerce_order_total' => $this->t('Order Number'),
+      'revision_id' => $this->t('Revision ID'),
+      'type' => $this->t('Type'),
+      'uid' => $this->t('User ID'),
+      'mail' => $this->t('Email'),
+      'status' => $this->t('Status'),
+      'created' => $this->t('Created'),
+      'changed' => $this->t('Changed'),
+      'default_store_id' => $this->t('Default store id'),
+      'refresh_state' => $this->t('Order refresh state'),
+      'hostname' => $this->t('Hostname'),
+      'data' => $this->t('Data'),
     ];
   }
 
diff --git a/modules/commerce/src/Plugin/migrate/source/commerce1/OrderItemType.php b/modules/commerce/src/Plugin/migrate/source/commerce1/OrderItemType.php
index ebceab5..32cfb5d 100644
--- a/modules/commerce/src/Plugin/migrate/source/commerce1/OrderItemType.php
+++ b/modules/commerce/src/Plugin/migrate/source/commerce1/OrderItemType.php
@@ -28,7 +28,7 @@ class OrderItemType extends DrupalSqlBase {
    */
   public function fields() {
     return [
-      'type' => t('Type'),
+      'type' => $this->t('Type'),
     ];
   }
 
diff --git a/modules/commerce/src/Plugin/migrate/source/commerce1/ProductDisplay.php b/modules/commerce/src/Plugin/migrate/source/commerce1/ProductDisplay.php
index 1774b1e..0141dee 100644
--- a/modules/commerce/src/Plugin/migrate/source/commerce1/ProductDisplay.php
+++ b/modules/commerce/src/Plugin/migrate/source/commerce1/ProductDisplay.php
@@ -56,15 +56,15 @@ class ProductDisplay extends FieldableEntity {
    */
   public function fields() {
     return [
-      'nid' => t('Product (variation) ID'),
-      'title' => t('Title'),
-      'type' => t('Type'),
-      'uid' => t('Owner'),
-      'status' => t('Status'),
-      'created' => t('Created'),
-      'changed' => t('Changes'),
-      'field_name' => t('Field name for variations'),
-      'variations_field' => t('Value of the product reference field'),
+      'nid' => $this->t('Product (variation) ID'),
+      'title' => $this->t('Title'),
+      'type' => $this->t('Type'),
+      'uid' => $this->t('Owner'),
+      'status' => $this->t('Status'),
+      'created' => $this->t('Created'),
+      'changed' => $this->t('Changes'),
+      'field_name' => $this->t('Field name for variations'),
+      'variations_field' => $this->t('Value of the product reference field'),
     ];
   }
 
diff --git a/modules/commerce/src/Plugin/migrate/source/commerce1/ProductDisplayType.php b/modules/commerce/src/Plugin/migrate/source/commerce1/ProductDisplayType.php
index b51e93e..bddfdf1 100644
--- a/modules/commerce/src/Plugin/migrate/source/commerce1/ProductDisplayType.php
+++ b/modules/commerce/src/Plugin/migrate/source/commerce1/ProductDisplayType.php
@@ -20,13 +20,13 @@ class ProductDisplayType extends DrupalSqlBase {
    */
   public function fields() {
     return [
-      'field_name' => t('Product reference field name'),
-      'type' => t('Type'),
-      'name' => t('Name'),
-      'description' => t('Description'),
-      'help' => t('Help'),
-      'data' => t('Product reference field instance data'),
-      'variation_type' => t('Product variation type'),
+      'field_name' => $this->t('Product reference field name'),
+      'type' => $this->t('Type'),
+      'name' => $this->t('Name'),
+      'description' => $this->t('Description'),
+      'help' => $this->t('Help'),
+      'data' => $this->t('Product reference field instance data'),
+      'variation_type' => $this->t('Product variation type'),
     ];
   }
 
diff --git a/modules/commerce/src/Plugin/migrate/source/commerce1/ProductType.php b/modules/commerce/src/Plugin/migrate/source/commerce1/ProductType.php
index 1edbbf2..be0728b 100644
--- a/modules/commerce/src/Plugin/migrate/source/commerce1/ProductType.php
+++ b/modules/commerce/src/Plugin/migrate/source/commerce1/ProductType.php
@@ -20,12 +20,12 @@ class ProductType extends DrupalSqlBase {
    */
   public function fields() {
     return [
-      'type' => t('Type'),
-      'name' => t('Name'),
-      'description' => t('Description'),
-      'help' => t('Help'),
-      'revision' => t('Revision'),
-      'line_item_type' => t('Line item type'),
+      'type' => $this->t('Type'),
+      'name' => $this->t('Name'),
+      'description' => $this->t('Description'),
+      'help' => $this->t('Help'),
+      'revision' => $this->t('Revision'),
+      'line_item_type' => $this->t('Line item type'),
     ];
   }
 
diff --git a/modules/commerce/src/Plugin/migrate/source/commerce1/ProductVariations.php b/modules/commerce/src/Plugin/migrate/source/commerce1/ProductVariations.php
index 580049b..0bce50a 100644
--- a/modules/commerce/src/Plugin/migrate/source/commerce1/ProductVariations.php
+++ b/modules/commerce/src/Plugin/migrate/source/commerce1/ProductVariations.php
@@ -21,16 +21,16 @@ class ProductVariations extends FieldableEntity {
    */
   public function fields() {
     return [
-      'product_id' => t('Product variation ID'),
-      'sku' => t('SKU'),
-      'title' => t('Title'),
-      'type' => t('Type'),
-      'language' => t('Language'),
-      'status' => t('Status'),
-      'created' => t('Created'),
-      'changed' => t('Changes'),
-      'data' => t('Data'),
-      'commerce_price' => t('Price with amount, currency_code and fraction_digits'),
+      'product_id' => $this->t('Product variation ID'),
+      'sku' => $this->t('SKU'),
+      'title' => $this->t('Title'),
+      'type' => $this->t('Type'),
+      'language' => $this->t('Language'),
+      'status' => $this->t('Status'),
+      'created' => $this->t('Created'),
+      'changed' => $this->t('Changes'),
+      'data' => $this->t('Data'),
+      'commerce_price' => $this->t('Price with amount, currency_code and fraction_digits'),
     ];
   }
 
diff --git a/modules/commerce/src/Plugin/migrate/source/commerce1/Profile.php b/modules/commerce/src/Plugin/migrate/source/commerce1/Profile.php
index 6a3d3c3..2e50faf 100644
--- a/modules/commerce/src/Plugin/migrate/source/commerce1/Profile.php
+++ b/modules/commerce/src/Plugin/migrate/source/commerce1/Profile.php
@@ -62,8 +62,8 @@ class Profile extends FieldableEntity {
       'changed' => $this->t('Modified timestamp'),
       'data' => $this->t('Data blob'),
       'cad_type' => $this->t('Type, if matching entry in defaults table'),
-      'revision_id' => t('The primary identifier for this version.'),
-      'revision_uid' => t('The primary identifier for this revision.'),
+      'revision_id' => $this->t('The primary identifier for this version.'),
+      'revision_uid' => $this->t('The primary identifier for this revision.'),
       'log' => $this->t('Revision Log message'),
       'revision_timestamp' => $this->t('Revision timestamp'),
       'revision_data' => $this->t('The revision data'),
diff --git a/modules/commerce/src/Plugin/migrate/source/commerce1/ShippingFlatRate.php b/modules/commerce/src/Plugin/migrate/source/commerce1/ShippingFlatRate.php
index 7ab7588..3bebee4 100644
--- a/modules/commerce/src/Plugin/migrate/source/commerce1/ShippingFlatRate.php
+++ b/modules/commerce/src/Plugin/migrate/source/commerce1/ShippingFlatRate.php
@@ -30,15 +30,15 @@ class ShippingFlatRate extends DrupalSqlBase {
    */
   public function fields() {
     return [
-      'name' => t('Flat rate service name'),
-      'title' => t('Flat rate title'),
-      'display_title' => t('Flat rate display title'),
-      'description' => t('Description'),
-      'rules_component' => t('Rules component'),
-      'amount' => t('Amount'),
-      'number' => t('The amount converted to a Commerce price amount'),
-      'currency_code' => t('Currency code'),
-      'data' => t('Shipping data'),
+      'name' => $this->t('Flat rate service name'),
+      'title' => $this->t('Flat rate title'),
+      'display_title' => $this->t('Flat rate display title'),
+      'description' => $this->t('Description'),
+      'rules_component' => $this->t('Rules component'),
+      'amount' => $this->t('Amount'),
+      'number' => $this->t('The amount converted to a Commerce price amount'),
+      'currency_code' => $this->t('Currency code'),
+      'data' => $this->t('Shipping data'),
     ];
   }
 
diff --git a/modules/commerce/tests/src/Functional/commerce1/MigrateUpgradeAddToCartTest.php b/modules/commerce/tests/src/Functional/commerce1/MigrateUpgradeAddToCartTest.php
index 76f561a..613356a 100644
--- a/modules/commerce/tests/src/Functional/commerce1/MigrateUpgradeAddToCartTest.php
+++ b/modules/commerce/tests/src/Functional/commerce1/MigrateUpgradeAddToCartTest.php
@@ -119,19 +119,19 @@ class MigrateUpgradeAddToCartTest extends MigrateUpgradeTestBase {
     // Start the upgrade process.
     $this->drupalGet('/upgrade');
 
-    $this->drupalPostForm(NULL, [], t('Continue'));
+    $this->drupalPostForm(NULL, [], 'Continue');
     $session->pageTextContains('Provide credentials for the database of the Drupal site you want to upgrade.');
     $session->fieldExists('mysql[host]');
 
-    $this->drupalPostForm(NULL, $edits, t('Review upgrade'));
+    $this->drupalPostForm(NULL, $edits, 'Review upgrade');
     $session->statusCodeEquals(200);
 
-    $this->drupalPostForm(NULL, [], t('Perform upgrade'));
+    $this->drupalPostForm(NULL, [], 'Perform upgrade');
 
     // Add to cart.
     \Drupal::service('commerce_cart.cart_provider')->createCart('default');
     $this->drupalGet('/product/15');
-    $this->drupalPostForm(NULL, [], t('Add to cart'));
+    $this->drupalPostForm(NULL, [], 'Add to cart');
     $session->pageTextContains('Tote Bag 1 added to your cart.');
   }
 
diff --git a/modules/commerce/tests/src/Functional/commerce1/MigrateUpgradeCommerce1Test.php b/modules/commerce/tests/src/Functional/commerce1/MigrateUpgradeCommerce1Test.php
index a89fb94..c7165c4 100644
--- a/modules/commerce/tests/src/Functional/commerce1/MigrateUpgradeCommerce1Test.php
+++ b/modules/commerce/tests/src/Functional/commerce1/MigrateUpgradeCommerce1Test.php
@@ -123,14 +123,14 @@ class MigrateUpgradeCommerce1Test extends MigrateUpgradeTestBase {
     // Start the upgrade process.
     $this->drupalGet('/upgrade');
 
-    $this->drupalPostForm(NULL, [], t('Continue'));
+    $this->drupalPostForm(NULL, [], 'Continue');
     $session->pageTextContains('Provide credentials for the database of the Drupal site you want to upgrade.');
     $session->fieldExists('mysql[host]');
 
-    $this->drupalPostForm(NULL, $edits, t('Review upgrade'));
+    $this->drupalPostForm(NULL, $edits, 'Review upgrade');
     $session->statusCodeEquals(200);
 
-    $this->drupalPostForm(NULL, [], t('Perform upgrade'));
+    $this->drupalPostForm(NULL, [], 'Perform upgrade');
 
     // Have to reset all the statics after migration to ensure entities are
     // loadable.
diff --git a/modules/commerce/tests/src/Unit/Plugin/migrate/process/commerce1/CommerceAttributeTargetTypeTest.php b/modules/commerce/tests/src/Unit/Plugin/migrate/process/commerce1/CommerceAttributeTargetTypeTest.php
index fb70b97..698a108 100644
--- a/modules/commerce/tests/src/Unit/Plugin/migrate/process/commerce1/CommerceAttributeTargetTypeTest.php
+++ b/modules/commerce/tests/src/Unit/Plugin/migrate/process/commerce1/CommerceAttributeTargetTypeTest.php
@@ -37,7 +37,6 @@ class CommerceAttributeTargetTypeTest extends MigrateProcessTestCase {
       ->method('getSourceProperty')
       ->will($this->onConsecutiveCalls($src[0], $src[1], $src[2]));
 
-    $configuration = [];
     $value = $this->plugin->transform('', $this->migrateExecutable, $this->row, $dst);
     $this->assertSame($expected, $value);
   }
diff --git a/modules/ubercart/src/Plugin/migrate/source/ShippingFlatRate.php b/modules/ubercart/src/Plugin/migrate/source/ShippingFlatRate.php
index f34ec20..adbe41e 100644
--- a/modules/ubercart/src/Plugin/migrate/source/ShippingFlatRate.php
+++ b/modules/ubercart/src/Plugin/migrate/source/ShippingFlatRate.php
@@ -27,12 +27,12 @@ class ShippingFlatRate extends DrupalSqlBase {
    */
   public function fields() {
     return [
-      'mid' => t('Method id'),
-      'title' => t('Flat rate title'),
-      'label' => t('Flat rate label'),
-      'base_rate' => t('Base rate'),
-      'product_rate' => t('Product rate'),
-      'currency_code' => t('Currency code'),
+      'mid' => $this->t('Method id'),
+      'title' => $this->t('Flat rate title'),
+      'label' => $this->t('Flat rate label'),
+      'base_rate' => $this->t('Base rate'),
+      'product_rate' => $this->t('Product rate'),
+      'currency_code' => $this->t('Currency code'),
     ];
   }
 
diff --git a/modules/ubercart/tests/src/Functional/MigrateUpgradeExecuteTestBase.php b/modules/ubercart/tests/src/Functional/MigrateUpgradeExecuteTestBase.php
index c265c43..d9f11f2 100644
--- a/modules/ubercart/tests/src/Functional/MigrateUpgradeExecuteTestBase.php
+++ b/modules/ubercart/tests/src/Functional/MigrateUpgradeExecuteTestBase.php
@@ -59,18 +59,18 @@ abstract class MigrateUpgradeExecuteTestBase extends CoreMigrateUpgradeExecuteTe
     // Start the upgrade process.
     $this->drupalGet('/upgrade');
 
-    $this->drupalPostForm(NULL, [], t('Continue'));
+    $this->drupalPostForm(NULL, [], 'Continue');
     $session->pageTextContains('Provide credentials for the database of the Drupal site you want to upgrade.');
     $session->fieldExists('mysql[host]');
 
-    $this->drupalPostForm(NULL, $edits, t('Review upgrade'));
+    $this->drupalPostForm(NULL, $edits, 'Review upgrade');
     $session->statusCodeEquals(200);
 
-    $this->drupalPostForm(NULL, [], t('I acknowledge I may lose data. Continue anyway.'));
+    $this->drupalPostForm(NULL, [], 'I acknowledge I may lose data. Continue anyway.');
     $session->statusCodeEquals(200);
 
-    $this->drupalPostForm(NULL, [], t('Perform upgrade'));
-    $session->pageTextContains(t('Congratulations, you upgraded Drupal!'));
+    $this->drupalPostForm(NULL, [], 'Perform upgrade');
+    $session->pageTextContains('Congratulations, you upgraded Drupal!');
     $this->assertMigrationResults($this->getEntityCounts(), $version);
   }
 
diff --git a/modules/ubercart/tests/src/Functional/MigrateUpgradeReviewPageTestBase.php b/modules/ubercart/tests/src/Functional/MigrateUpgradeReviewPageTestBase.php
index e20bb5f..3cc83e0 100644
--- a/modules/ubercart/tests/src/Functional/MigrateUpgradeReviewPageTestBase.php
+++ b/modules/ubercart/tests/src/Functional/MigrateUpgradeReviewPageTestBase.php
@@ -100,9 +100,9 @@ abstract class MigrateUpgradeReviewPageTestBase extends MigrateUpgradeTestBase {
 
     // Start the upgrade process.
     $this->drupalGet('/upgrade');
-    $this->drupalPostForm(NULL, [], t('Continue'));
-    $this->drupalPostForm(NULL, $edits, t('Review upgrade'));
-    $this->drupalPostForm(NULL, [], t('I acknowledge I may lose data. Continue anyway.'));
+    $this->drupalPostForm(NULL, [], 'Continue');
+    $this->drupalPostForm(NULL, $edits, 'Review upgrade');
+    $this->drupalPostForm(NULL, [], 'I acknowledge I may lose data. Continue anyway.');
 
     // Ensure there are no errors about missing modules from the test module.
     $session = $this->assertSession();
diff --git a/modules/ubercart/tests/src/Functional/uc6/MigrateUpgradeAddToCartTest.php b/modules/ubercart/tests/src/Functional/uc6/MigrateUpgradeAddToCartTest.php
index 6101c29..30ca2da 100644
--- a/modules/ubercart/tests/src/Functional/uc6/MigrateUpgradeAddToCartTest.php
+++ b/modules/ubercart/tests/src/Functional/uc6/MigrateUpgradeAddToCartTest.php
@@ -119,14 +119,14 @@ class MigrateUpgradeAddToCartTest extends MigrateUpgradeTestBase {
     // Start the upgrade process.
     $this->drupalGet('/upgrade');
 
-    $this->drupalPostForm(NULL, [], t('Continue'));
+    $this->drupalPostForm(NULL, [], 'Continue');
     $session->pageTextContains('Provide credentials for the database of the Drupal site you want to upgrade.');
     $session->fieldExists('mysql[host]');
 
-    $this->drupalPostForm(NULL, $edits, t('Review upgrade'));
+    $this->drupalPostForm(NULL, $edits, 'Review upgrade');
     $session->statusCodeEquals(200);
 
-    $this->drupalPostForm(NULL, [], t('Perform upgrade'));
+    $this->drupalPostForm(NULL, [], 'Perform upgrade');
 
     // Prevent error that the new field, field_order_admin_comments does not
     // exist on the entity type commerce_order.
@@ -135,7 +135,7 @@ class MigrateUpgradeAddToCartTest extends MigrateUpgradeTestBase {
     // Add to cart.
     \Drupal::service('commerce_cart.cart_provider')->createCart('default');
     $this->drupalGet('/product/2');
-    $this->drupalPostForm(NULL, [], t('Add to cart'));
+    $this->drupalPostForm(NULL, [], 'Add to cart');
     $session->pageTextContains('Beach Towel added to your cart.');
   }
 
diff --git a/tests/src/Functional/MigrateUpgradeReviewPageTestBase.php b/tests/src/Functional/MigrateUpgradeReviewPageTestBase.php
index 491625b..4beac7e 100644
--- a/tests/src/Functional/MigrateUpgradeReviewPageTestBase.php
+++ b/tests/src/Functional/MigrateUpgradeReviewPageTestBase.php
@@ -85,8 +85,8 @@ abstract class MigrateUpgradeReviewPageTestBase extends MigrateUpgradeTestBase {
 
     // Start the upgrade process.
     $this->drupalGet('/upgrade');
-    $this->drupalPostForm(NULL, [], t('Continue'));
-    $this->drupalPostForm(NULL, $edits, t('Review upgrade'));
+    $this->drupalPostForm(NULL, [], 'Continue');
+    $this->drupalPostForm(NULL, $edits, 'Review upgrade');
 
     // Ensure there are no errors about missing modules from the test module.
     $session = $this->assertSession();
diff --git a/tests/src/Kernel/CommerceMigrateCoreTestTrait.php b/tests/src/Kernel/CommerceMigrateCoreTestTrait.php
index dcfbe20..1c37605 100644
--- a/tests/src/Kernel/CommerceMigrateCoreTestTrait.php
+++ b/tests/src/Kernel/CommerceMigrateCoreTestTrait.php
@@ -96,7 +96,7 @@ trait CommerceMigrateCoreTestTrait {
    * @param array $expected_parents
    *   The parent terms the migrated entity should have.
    */
-  protected function assertTermEntity($id, $expected_label, $expected_vid, $expected_description = '', $expected_format = NULL, $expected_weight = 0, array $expected_parents) {
+  protected function assertTermEntity($id, $expected_label, $expected_vid, $expected_description = '', $expected_format = NULL, $expected_weight = 0, array $expected_parents = []) {
     /** @var \Drupal\taxonomy\TermInterface $entity */
     $entity = Term::load($id);
     $this->assertInstanceOf(TermInterface::class, $entity);
diff --git a/tests/src/Kernel/CsvTestBase.php b/tests/src/Kernel/CsvTestBase.php
index 7d99705..975364b 100644
--- a/tests/src/Kernel/CsvTestBase.php
+++ b/tests/src/Kernel/CsvTestBase.php
@@ -211,6 +211,8 @@ abstract class CsvTestBase extends MigrateTestBase {
         }
         else {
           if (!$file_system->copy($src . '/' . $file, $dst . '/' . $file)) {
+            $fixture = $src . '/' . $file;
+            $destination_uri = $dst . '/' . $file;
             throw new MigrateException("Migration setup failed to copy source CSV file '$fixture' to '$destination_uri'.");
           }
         }