Auto-assign the sole visible category in StartRegistration when no category field is shown (Case 212902) (#33)

When only one newsletter category existed, TypeHasCategoriesElementTrait
skipped adding the categories field to the form. As a result, the model
transformer created a PendingOptIn with no categories, and the confirmed
Recipient ended up stored with no subscriptions.

StartRegistration\Type now detects this case inside the model
transformer's reverseTransform and injects the single visible category
into the form data before passing it to the PendingOptInFactory.

As part of this, addCategoriesElementToForm() was refactored: the trait
no longer calls findVisible() itself or owns the categoryRepository
property. Instead, it receives the pre-fetched choices as a parameter
and unconditionally adds the field. The decision of whether to call
addCategoriesElementToForm() at all now rests with the calling types
(StartRegistration\Type and EditRegistration\Type), which avoids a
second findVisible() call and separates the concerns of fetching
categories and rendering the form field.

Author: janopae

src/EditRegistration/Type.php

@@ -12,6 +12,7 @@ class Type extends AbstractType
     use TypeHasCategoriesElementTrait;
 
     public const ELEMENT_CATEGORIES = 'categories';
+    protected CategoryRepositoryInterface $categoryRepository;
 
     public function __construct(CategoryRepositoryInterface $categoryRepository)
     {
@@ -20,7 +21,11 @@ public function __construct(CategoryRepositoryInterface $categoryRepository)
 
     public function buildForm(FormBuilderInterface $builder, array $options): void
     {
-        $this->addCategoriesElementToForm($builder, false);
+        $choices = $this->categoryRepository->findVisible();
+
+        if (\count($choices) > 1) {
+            $this->addCategoriesElementToForm($builder, $choices, false);
+        }
 
         // We need at least one element in addition to the categories above, so that Symfony recognizes the form being
         // submitted even if no categories where chosen.

src/EditRegistration/TypeHasCategoriesElementTrait.php

@@ -5,20 +5,11 @@
 use Symfony\Component\Form\Extension\Core\Type\ChoiceType;
 use Symfony\Component\Form\FormBuilderInterface;
 use Symfony\Component\Validator\Constraints\Choice;
-use Webfactory\NewsletterRegistrationBundle\Entity\CategoryRepositoryInterface;
 
 trait TypeHasCategoriesElementTrait
 {
-    protected CategoryRepositoryInterface $categoryRepository;
-
-    protected function addCategoriesElementToForm(FormBuilderInterface $builder, bool $recipientHasToChooseAtLeastOne)
+    protected function addCategoriesElementToForm(FormBuilderInterface $builder, array $choices, bool $recipientHasToChooseAtLeastOne): void
     {
-        // add category choices, if there is more than one
-        $choices = $this->categoryRepository->findVisible();
-        if (\count($choices) < 2) {
-            return;
-        }
-
         $constraints = [];
         if (true === $recipientHasToChooseAtLeastOne) {
             $constraints[] = new Choice(choices: $choices, multiple: true, min: 1);

src/StartRegistration/Type.php

@@ -19,6 +19,7 @@ class Type extends AbstractType
     public const ELEMENT_HONEYPOT = 'url';
 
     protected PendingOptInFactoryInterface $pendingOptInFactory;
+    protected CategoryRepositoryInterface $categoryRepository;
 
     public function __construct(CategoryRepositoryInterface $categoryRepository, PendingOptInFactoryInterface $pendingOptInFactory)
     {
@@ -30,7 +31,11 @@ public function buildForm(FormBuilderInterface $builder, array $options): void
     {
         $builder->add(static::ELEMENT_EMAIL_ADDRESS, EmailAddressType::class);
 
-        $this->addCategoriesElementToForm($builder, true);
+        $choices = $this->categoryRepository->findVisible();
+
+        if (\count($choices) > 1) {
+            $this->addCategoriesElementToForm($builder, $choices, true);
+        }
 
         // fake field for spam protection
         $builder->add(static::ELEMENT_HONEYPOT, HoneypotType::class);
@@ -47,7 +52,14 @@ function (?PendingOptInInterface $pendingOptIn): array {
                     static::ELEMENT_CATEGORIES => $pendingOptIn->getCategories(),
                 ];
             },
-            function (array $formData) use ($that): ?PendingOptInInterface {
+            function (array $formData) use ($that, $choices): ?PendingOptInInterface {
+                if (!isset($formData[self::ELEMENT_CATEGORIES]) && 1 === \count($choices)) {
+                    // if the field 'categories' is not in the form because you could choose only one anyway, we need to
+                    // set that one category here.
+                    $singleCategory = $choices[0];
+                    $formData[self::ELEMENT_CATEGORIES] = [$singleCategory];
+                }
+
                 return $that->pendingOptInFactory->fromRegistrationFormData($formData);
             }
         ));

tests/StartRegistration/TypeTest.php

@@ -240,6 +240,34 @@ function (array $formData) {
         $this->assertEquals($pendingOptIn, $form->getData());
     }
 
+    #[Test]
+    public function provides_PendingOptIn_with_single_category_auto_assigned_when_only_one_exists(): void
+    {
+        $this->setUpOneCategory();
+
+        $pendingOptIn = new PendingOptIn(null, new EmailAddress('webfactory@example.com', 'secret'), [$this->category1]);
+        $this->pendingOptInFactory
+            ->method('fromRegistrationFormData')
+            ->with(
+                $this->callback(
+                    function (array $formData) {
+                        return \array_key_exists(StartRegistrationType::ELEMENT_CATEGORIES, $formData)
+                            && $formData[StartRegistrationType::ELEMENT_CATEGORIES] === [$this->category1];
+                    }
+                )
+            )
+            ->willReturn($pendingOptIn);
+
+        $form = $this->factory->create(StartRegistrationType::class);
+        $form->submit([
+            StartRegistrationType::ELEMENT_EMAIL_ADDRESS => 'webfactory@example.com',
+            StartRegistrationType::ELEMENT_HONEYPOT => '',
+        ]);
+
+        $this->assertTrue($form->isValid());
+        $this->assertEquals($pendingOptIn, $form->getData());
+    }
+
     #[Test]
     public function provides_PendingOptIn_if_submitted_with_valid_data_and_category_choices()
     {