Call to a member function getValue() on null when calling the addTranslation() method on EntityStub

Problem/Motivation

Seems there is a problem with addTranslation() method in mocked entity stubs.

Steps to reproduce

    $block1Values = [
      'type' => 'my_blocktype',
    ];
    $block1 = $this->entityStubFactory->create(BlockContent::class, $block1Values);
    $block1->addTranslation('en', $block1Values);
    $block1->save()

Is showing the error:

Error: Call to a member function getValue() on null

/var/www/html/docroot/core/lib/Drupal/Core/Field/FieldItemList.php:50

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes