refactor: Update CreateUsecase to allow default values on entities

Previously we created a blank entity and set state on it, this meant
that any values that had a default value *and* were marked as immutable
could not be set ie. `Post->type`. Instead CreateUsecase now creates
the entity with the full payload data, so the default are only applied
where the values doesn't appear in the payload, and the immutable
check works correctly because the value isn't yet set.

Author: rjmackay

src/App/Repository/PostRepository.php

@@ -129,7 +129,7 @@ public function getEntity(array $data = null)
             )
         );
 
-        if ($data['form_id']) {
+        if (!empty($data['form_id'])) {
             // Get Hidden Stage Ids to be excluded from results
             $excludeStages = $this->form_stage_repo->getHiddenStageIds(
                 $data['form_id'],

src/Core/Entity/Post.php

@@ -47,6 +47,16 @@ class Post extends StaticEntity
     protected $contact_id;
     protected $data_source_message_id;
 
+    // StatefulData
+    protected function getDefaultData()
+    {
+        return [
+            'type' => 'report',
+            'locale' => 'en_US',
+            'published_to' => [],
+        ];
+    }
+
     // StatefulData
     protected function getDerived()
     {

src/Core/Usecase/CreateUsecase.php

@@ -111,7 +111,7 @@ protected function verifyValid(Entity $entity)
      */
     protected function getEntity()
     {
-        return $this->repo->getEntity()->setState($this->payload);
+        return $this->repo->getEntity($this->payload);
     }
 
     /**

tests/spec/Core/Usecase/CreateUsecaseSpec.php

@@ -35,8 +35,7 @@ private function tryGetEntity($repo, $entity)
         $this->setPayload($payload);
 
         // Called by CreateUsecase::getEntity
-        $repo->getEntity()->willReturn($entity);
-        $entity->setState($payload)->willReturn($entity);
+        $repo->getEntity($payload)->willReturn($entity);
     }
 
     function it_fails_when_authorization_is_denied($auth, $repo, Entity $entity)