feature #57935 [DoctrineBridge] Loosened CollectionToArrayTransformer::transform() to accept ReadableCollection (timdev)

This PR was merged into the 7.2 branch.

Discussion
----------

[DoctrineBridge] Loosened CollectionToArrayTransformer::transform() to accept ReadableCollection

Since 1.8.0 doctrine/collections ships ReadableCollection, which the Collection interface extends. This commit relaxes the behavior of CollectionToArrayTransformer::transform(), allowing it to tranform instances of ReadableCollection.

| Q             | A
| ------------- | ---
| Branch?       | 7.2
| Bug fix?      | no
| New feature?  | yes
| Deprecations? | no
| Issues        |
| License       | MIT

Since 1.8.0 doctrine/collections ships ReadableCollection, which the Collection interface extends. This commit relaxes the behavior of CollectionToArrayTransformer::transform(), allowing it to transform instances of ReadableCollection.

This change does not break BC, but does make `doctrine/collections` a non-dev dependency in order to require at least `1.8.0` of that library (previously, the lower-bound version was implicitly `^1.5` via `doctrine/o[rd]m`. This is one of several reasons why I'm considering this an addition and not a bugfix. Symfony maintainers are, of course, welcome to backport this patch to earlier versions of the framework at their discretion.

I've omitted a test here, since the signal:noise ratio would be poor due the the necessary inclusion of a boilerplate ReadableCollection implementation. I'm happy to add one if desired, however.

Commits
-------

a13f0ac92e [DoctrineBridge] Loosened CollectionToArrayTransformer::transform() to accept ReadableCollection

Author: nicolas-grekas

CHANGELOG.md

@@ -1,6 +1,11 @@
 CHANGELOG
 =========
 
+7.2
+---
+
+ * Accept `ReadableCollection` in `CollectionToArrayTransformer`
+
 7.1
 ---
 

Form/DataTransformer/CollectionToArrayTransformer.php

@@ -13,6 +13,7 @@
 
 use Doctrine\Common\Collections\ArrayCollection;
 use Doctrine\Common\Collections\Collection;
+use Doctrine\Common\Collections\ReadableCollection;
 use Symfony\Component\Form\DataTransformerInterface;
 use Symfony\Component\Form\Exception\TransformationFailedException;
 
@@ -40,8 +41,8 @@ public function transform(mixed $collection): mixed
             return $collection;
         }
 
-        if (!$collection instanceof Collection) {
-            throw new TransformationFailedException('Expected a Doctrine\Common\Collections\Collection object.');
+        if (!$collection instanceof ReadableCollection) {
+            throw new TransformationFailedException(\sprintf('Expected a "%s" object.', ReadableCollection::class));
         }
 
         return $collection->toArray();

Tests/Form/DataTransformer/CollectionToArrayTransformerTest.php

@@ -12,6 +12,7 @@
 namespace Symfony\Bridge\Doctrine\Tests\Form\DataTransformer;
 
 use Doctrine\Common\Collections\ArrayCollection;
+use Doctrine\Common\Collections\ReadableCollection;
 use PHPUnit\Framework\TestCase;
 use Symfony\Bridge\Doctrine\Form\DataTransformer\CollectionToArrayTransformer;
 use Symfony\Component\Form\Exception\TransformationFailedException;
@@ -66,6 +67,118 @@ public function testTransformExpectsArrayOrCollection()
         $this->transformer->transform('Foo');
     }
 
+    public function testTransformReadableCollection()
+    {
+        $array = [
+            2 => 'foo',
+            3 => 'bar',
+        ];
+
+        $collection = new class($array) implements ReadableCollection
+        {
+            public function __construct(private readonly array $array)
+            {
+            }
+
+            public function contains($element): bool
+            {
+            }
+
+            public function isEmpty(): bool
+            {
+            }
+
+            public function containsKey($key): bool
+            {
+            }
+
+            public function get($key): mixed
+            {
+            }
+
+            public function getKeys(): array
+            {
+            }
+
+            public function getValues(): array
+            {
+            }
+
+            public function toArray(): array
+            {
+                return $this->array;
+            }
+
+            public function first(): mixed
+            {
+            }
+
+            public function last(): mixed
+            {
+            }
+
+            public function key(): string|int|null
+            {
+            }
+
+            public function current(): mixed
+            {
+            }
+
+            public function next(): mixed
+            {
+            }
+
+            public function slice($offset, $length = null): array
+            {
+            }
+
+            public function exists(\Closure $p): bool
+            {
+            }
+
+            public function filter(\Closure $p): ReadableCollection
+            {
+            }
+
+            public function map(\Closure $func): ReadableCollection
+            {
+            }
+
+            public function partition(\Closure $p): array
+            {
+            }
+
+            public function forAll(\Closure $p): bool
+            {
+            }
+
+            public function indexOf($element): int|string|bool
+            {
+            }
+
+            public function findFirst(\Closure $p): mixed
+            {
+            }
+
+            public function reduce(\Closure $func, mixed $initial = null): mixed
+            {
+            }
+
+            public function getIterator(): \Traversable
+            {
+                return new \ArrayIterator($this->array);
+            }
+
+            public function count(): int
+            {
+                return count($this->array);
+            }
+        };
+
+        $this->assertSame($array, $this->transformer->transform($collection));
+    }
+
     public function testReverseTransform()
     {
         $array = [

composer.json

@@ -43,13 +43,14 @@
         "symfony/uid": "^6.4|^7.0",
         "symfony/validator": "^6.4|^7.0",
         "symfony/var-dumper": "^6.4|^7.0",
-        "doctrine/collections": "^1.0|^2.0",
+        "doctrine/collections": "^1.8|^2.0",
         "doctrine/data-fixtures": "^1.1",
         "doctrine/dbal": "^3.6|^4",
         "doctrine/orm": "^2.15|^3",
         "psr/log": "^1|^2|^3"
     },
     "conflict": {
+        "doctrine/collections": "<1.8",
         "doctrine/dbal": "<3.6",
         "doctrine/lexer": "<1.1",
         "doctrine/orm": "<2.15",