Test content entity source preview.
public function testSourceUpdate() {
// Create translatable node.
$node = $this
->createTranslatableNode('article', 'en');
$job = $this
->createJob('en', 'de');
$job
->save();
$job_item = tmgmt_job_item_create('content', $node
->getEntityTypeId(), $node
->id(), array(
'tjid' => $job
->id(),
));
$job_item
->save();
$this
->drupalGet($node
->toUrl('edit-form'));
$updated_body = 'New body';
$edit = [
'body[0][value]' => $updated_body,
];
$this
->submitForm($edit, 'Save');
$this
->drupalGet('admin/tmgmt/items/' . $job_item
->id());
$this
->assertSession()
->pageTextContains($updated_body);
}