Add DocGenNormalizerTestAbstract class

A new class, DocGenNormalizerTestAbstract, was added to the ChillDocGeneratorBundle. This abstract class tests the normalization of null values and ensures they comply with expected formats and behaviors. It implements key methods that allow for providing non-null objects, expectation setting, and normalization.

src/Bundle/ChillDocGeneratorBundle/Test/DocGenNormalizerTestAbstract.php

@@ -0,0 +1,65 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * Chill is a software for social workers
+ *
+ * For the full copyright and license information, please view
+ * the LICENSE file that was distributed with this source code.
+ */
+
+namespace Chill\DocGeneratorBundle\Test;
+
+use Symfony\Bundle\FrameworkBundle\Test\KernelTestCase;
+use Symfony\Component\Serializer\Normalizer\AbstractNormalizer;
+use Symfony\Component\Serializer\Normalizer\NormalizerInterface;
+
+/**
+ * @template T of object
+ */
+abstract class DocGenNormalizerTestAbstract extends KernelTestCase
+{
+    public function testNullValueHasSameKeysAsNull(): void
+    {
+        $normalizedObject = $this->getNormalizer()->normalize($this->provideNotNullObject(), 'docgen', [
+            AbstractNormalizer::GROUPS => ['docgen:read'], 'docgen:expects' => $this->provideDocGenExpectClass(),
+        ]);
+        $nullNormalizedObject = $this->getNormalizer()->normalize(null, 'docgen', [
+            AbstractNormalizer::GROUPS => ['docgen:read'], 'docgen:expects' => $this->provideDocGenExpectClass(),
+        ]);
+
+        self::assertEqualsCanonicalizing(array_keys($normalizedObject), array_keys($nullNormalizedObject));
+        self::assertArrayHasKey('isNull', $nullNormalizedObject, 'each object must have an "isNull" key');
+        self::assertTrue($nullNormalizedObject['isNull'], 'isNull key must be true for null objects');
+        self::assertFalse($normalizedObject['isNull'], 'isNull key must be false for null objects');
+
+        foreach ($normalizedObject as $key => $value) {
+            if (in_array($key, ['isNull', 'type'])) {
+                continue;
+            }
+
+            if (is_array($value)) {
+                if (array_is_list($value)) {
+                    self::assertEquals([], $nullNormalizedObject[$key], "list must be serialized as an empty array, in {$key}");
+                } else {
+                    self::assertEqualsCanonicalizing(array_keys($value), array_keys($nullNormalizedObject[$key]), "sub-object must have the same keys, in {$key}");
+                }
+            } elseif (is_string($value)) {
+                self::assertEquals('', $nullNormalizedObject[$key], 'strings must be ');
+            }
+        }
+    }
+
+    /**
+     * @return T
+     */
+    abstract public function provideNotNullObject(): object;
+
+    /**
+     * @return class-string<T>
+     */
+    abstract public function provideDocGenExpectClass(): string;
+
+    abstract public function getNormalizer(): NormalizerInterface;
+}