diff -u b/core/modules/file/tests/src/Unit/Plugin/migrate/field/d7/FileFieldTest.php b/core/modules/file/tests/src/Unit/Plugin/migrate/field/d7/FileFieldTest.php
--- b/core/modules/file/tests/src/Unit/Plugin/migrate/field/d7/FileFieldTest.php
+++ b/core/modules/file/tests/src/Unit/Plugin/migrate/field/d7/FileFieldTest.php
@@ -68,7 +68,7 @@
     $this->plugin->defineValueProcessPipeline($this->migration, 'somefieldname', []);
 
     $expected = [
-      'plugin' => 'iterator',
+      'plugin' => 'sub_process',
       'source' => 'somefieldname',
       'process' => [
         'target_id' => 'fid',
diff -u b/core/modules/file/tests/src/Unit/Plugin/migrate/field/d7/ImageFieldTest.php b/core/modules/file/tests/src/Unit/Plugin/migrate/field/d7/ImageFieldTest.php
--- b/core/modules/file/tests/src/Unit/Plugin/migrate/field/d7/ImageFieldTest.php
+++ b/core/modules/file/tests/src/Unit/Plugin/migrate/field/d7/ImageFieldTest.php
@@ -69,7 +69,7 @@
     $this->plugin->defineValueProcessPipeline($this->migration, 'somefieldname', []);
 
     $expected = [
-      'plugin' => 'iterator',
+      'plugin' => 'sub_process',
       'source' => 'somefieldname',
       'process' => [
         'target_id' => 'fid',
diff -u b/core/modules/taxonomy/tests/src/Unit/Plugin/migrate/cckfield/TaxonomyTermReferenceCckTest.php b/core/modules/taxonomy/tests/src/Unit/Plugin/migrate/cckfield/TaxonomyTermReferenceCckTest.php
--- b/core/modules/taxonomy/tests/src/Unit/Plugin/migrate/cckfield/TaxonomyTermReferenceCckTest.php
+++ b/core/modules/taxonomy/tests/src/Unit/Plugin/migrate/cckfield/TaxonomyTermReferenceCckTest.php
@@ -51,7 +51,7 @@
     $this->plugin->processCckFieldValues($this->migration, 'somefieldname', []);
 
     $expected = [
-      'plugin' => 'iterator',
+      'plugin' => 'sub_process',
       'source' => 'somefieldname',
       'process' => [
         'target_id' => 'tid',
@@ -83,7 +83,7 @@
     $this->plugin->defineValueProcessPipeline($this->migration, 'somefieldname', []);
 
     $expected = [
-      'plugin' => 'iterator',
+      'plugin' => 'sub_process',
       'source' => 'somefieldname',
       'process' => [
         'target_id' => 'tid',
diff -u b/core/modules/taxonomy/tests/src/Unit/Plugin/migrate/field/TaxonomyTermReferenceFieldTest.php b/core/modules/taxonomy/tests/src/Unit/Plugin/migrate/field/TaxonomyTermReferenceFieldTest.php
--- b/core/modules/taxonomy/tests/src/Unit/Plugin/migrate/field/TaxonomyTermReferenceFieldTest.php
+++ b/core/modules/taxonomy/tests/src/Unit/Plugin/migrate/field/TaxonomyTermReferenceFieldTest.php
@@ -66,7 +66,7 @@
     $this->plugin->defineValueProcessPipeline($this->migration, 'somefieldname', []);
 
     $expected = [
-      'plugin' => 'iterator',
+      'plugin' => 'sub_process',
       'source' => 'somefieldname',
       'process' => [
         'target_id' => 'tid',
diff -u b/core/modules/text/tests/src/Unit/Migrate/d6/TextFieldTest.php b/core/modules/text/tests/src/Unit/Migrate/d6/TextFieldTest.php
--- b/core/modules/text/tests/src/Unit/Migrate/d6/TextFieldTest.php
+++ b/core/modules/text/tests/src/Unit/Migrate/d6/TextFieldTest.php
@@ -78,7 +78,7 @@
     $this->plugin->defineValueProcessPipeline($this->migration, 'body', $field_info);
 
     $process = $this->migration->getProcess();
-    $this->assertSame('iterator', $process['plugin']);
+    $this->assertSame('sub_process', $process['plugin']);
     $this->assertSame('body', $process['source']);
     $this->assertSame('value', $process['process']['value']);
 
diff -u b/core/modules/text/tests/src/Unit/Plugin/migrate/field/d6/TextFieldTest.php b/core/modules/text/tests/src/Unit/Plugin/migrate/field/d6/TextFieldTest.php
--- b/core/modules/text/tests/src/Unit/Plugin/migrate/field/d6/TextFieldTest.php
+++ b/core/modules/text/tests/src/Unit/Plugin/migrate/field/d6/TextFieldTest.php
@@ -77,7 +77,7 @@
     $this->plugin->defineValueProcessPipeline($this->migration, 'body', $field_info);
 
     $process = $this->migration->getProcess();
-    $this->assertSame('iterator', $process['plugin']);
+    $this->assertSame('sub_process', $process['plugin']);
     $this->assertSame('body', $process['source']);
     $this->assertSame('value', $process['process']['value']);