feature #50934 [Form] Add duplicate_preferred_choices option to ChoiceType (arnaud-deabreu)

This PR was merged into the 6.4 branch.

Discussion
----------

[Form] Add `duplicate_preferred_choices` option to `ChoiceType`

| Q             | A
| ------------- | ---
| Branch?       | 6.4
| Bug fix?      | no
| New feature?  | yes
| Deprecations? | no
| Tickets       | Fix #35135
| License       | MIT
| Doc PR        | TODO

I've reintroduced layout tests as they were before #32658, is that enough? /cc `@xabbuh` :)
Thanks `@HeahDude` for your mentoring!

Commits
-------

df00a5fd69 [Form] Add `duplicate_preferred_choices` option to `ChoiceType`

Author: fabpot

Tests/Extension/AbstractBootstrap3LayoutTestCase.php

@@ -576,6 +576,31 @@ public function testSingleChoiceWithPreferred()
         );
     }
 
+    public function testSingleChoiceWithPreferredIsNotDuplicated()
+    {
+        $form = $this->factory->createNamed('name', 'Symfony\Component\Form\Extension\Core\Type\ChoiceType', '&a', [
+            'choices' => ['Choice&A' => '&a', 'Choice&B' => '&b'],
+            'preferred_choices' => ['&b'],
+            'duplicate_preferred_choices' => false,
+            'multiple' => false,
+            'expanded' => false,
+        ]);
+
+        $this->assertWidgetMatchesXpath($form->createView(), ['separator' => '-- sep --', 'attr' => ['class' => 'my&class']],
+            '/select
+    [@name="name"]
+    [@class="my&class form-control"]
+    [not(@required)]
+    [
+        ./option[@value="&b"][not(@selected)][.="[trans]Choice&B[/trans]"]
+        /following-sibling::option[@disabled="disabled"][not(@selected)][.="-- sep --"]
+        /following-sibling::option[@value="&a"][@selected="selected"][.="[trans]Choice&A[/trans]"]
+    ]
+    [count(./option)=3]
+'
+        );
+    }
+
     public function testSingleChoiceWithSelectedPreferred()
     {
         $form = $this->factory->createNamed('name', 'Symfony\Component\Form\Extension\Core\Type\ChoiceType', '&a', [

Tests/Extension/AbstractBootstrap5LayoutTestCase.php

@@ -584,6 +584,31 @@ public function testSingleChoiceWithPreferred()
         );
     }
 
+    public function testSingleChoiceWithPreferredIsNotDuplicated()
+    {
+        $form = $this->factory->createNamed('name', ChoiceType::class, '&a', [
+            'choices' => ['Choice&A' => '&a', 'Choice&B' => '&b'],
+            'preferred_choices' => ['&b'],
+            'duplicate_preferred_choices' => false,
+            'multiple' => false,
+            'expanded' => false,
+        ]);
+
+        $this->assertWidgetMatchesXpath($form->createView(), ['separator' => '-- sep --', 'attr' => ['class' => 'my&class']],
+            '/select
+    [@name="name"]
+    [@class="my&class form-select"]
+    [not(@required)]
+    [
+        ./option[@value="&b"][not(@selected)][.="[trans]Choice&B[/trans]"]
+        /following-sibling::option[@disabled="disabled"][not(@selected)][.="-- sep --"]
+        /following-sibling::option[@value="&a"][@selected="selected"][.="[trans]Choice&A[/trans]"]
+    ]
+    [count(./option)=3]
+'
+        );
+    }
+
     public function testSingleChoiceWithSelectedPreferred()
     {
         $form = $this->factory->createNamed('name', ChoiceType::class, '&a', [

composer.json

@@ -28,7 +28,7 @@
         "symfony/asset-mapper": "^6.3|^7.0",
         "symfony/dependency-injection": "^5.4|^6.0|^7.0",
         "symfony/finder": "^5.4|^6.0|^7.0",
-        "symfony/form": "^6.3|^7.0",
+        "symfony/form": "^6.4|^7.0",
         "symfony/html-sanitizer": "^6.1|^7.0",
         "symfony/http-foundation": "^5.4|^6.0|^7.0",
         "symfony/http-kernel": "^6.4|^7.0",