Skip optional values which were not provided in the data in the serialization result to avoid generating incompatible serialized values due to NULL fields (fixes #76)

Author: Enno Woortmann

composer.json

@@ -11,7 +11,7 @@
         }
     ],
     "require": {
-        "wol-soft/php-json-schema-model-generator-production": "^0.18.0",
+        "wol-soft/php-json-schema-model-generator-production": "^0.18.1",
         "wol-soft/php-micro-template": "^1.3.2",
 
         "php": ">=7.2",

src/SchemaProcessor/PostProcessor/Internal/SerializationPostProcessor.php

@@ -8,7 +8,11 @@
 use PHPModelGenerator\Filter\TransformingFilterInterface;
 use PHPModelGenerator\Interfaces\SerializationInterface;
 use PHPModelGenerator\Model\GeneratorConfiguration;
+use PHPModelGenerator\Model\Property\Property;
+use PHPModelGenerator\Model\Property\PropertyInterface;
+use PHPModelGenerator\Model\Property\PropertyType;
 use PHPModelGenerator\Model\Schema;
+use PHPModelGenerator\Model\SchemaDefinition\JsonSchema;
 use PHPModelGenerator\Model\Validator\AdditionalPropertiesValidator;
 use PHPModelGenerator\Model\Validator\FilterValidator;
 use PHPModelGenerator\Model\Validator\PatternPropertiesValidator;
@@ -40,6 +44,7 @@ public function process(Schema $schema, GeneratorConfiguration $generatorConfigu
 
         $this->addSerializeFunctionsForTransformingFilters($schema, $generatorConfiguration);
         $this->addSerializationHookMethod($schema, $generatorConfiguration);
+        $this->addSkipNotProvidedPropertiesMap($schema, $generatorConfiguration);
 
         $this->addPatternPropertiesSerialization($schema, $generatorConfiguration);
 
@@ -229,4 +234,36 @@ public function getCode(): string
             }
         );
     }
+
+    private function addSkipNotProvidedPropertiesMap(
+        Schema $schema,
+        GeneratorConfiguration $generatorConfiguration
+    ): void {
+        if ($generatorConfiguration->isImplicitNullAllowed()) {
+            return;
+        }
+
+        $skipNotProvidedValues = array_map(
+            static function (PropertyInterface $property): string {
+                return $property->getAttribute(true);
+            },
+            array_filter(
+                $schema->getProperties(),
+                static function (PropertyInterface $property): bool {
+                    return !$property->isRequired() && !$property->getDefaultValue();
+                }
+            )
+        );
+
+        $schema->addProperty(
+            (new Property(
+                'skipNotProvidedPropertiesMap',
+                new PropertyType('array'),
+                new JsonSchema(__FILE__, []),
+                'Values which might be skipped for serialization if not provided'
+            ))
+                ->setDefaultValue($skipNotProvidedValues)
+                ->setInternal(true)
+        );
+    }
 }

tests/Issues/Issue/Issue76Test.php

@@ -0,0 +1,45 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PHPModelGenerator\Tests\Issues\Issue;
+
+use PHPModelGenerator\Model\GeneratorConfiguration;
+use PHPModelGenerator\Tests\Issues\AbstractIssueTest;
+
+class Issue76Test extends AbstractIssueTest
+{
+    public function testSerializeWithImplicitNullEnabledIncludesAllFields(): void
+    {
+        $className = $this->generateClassFromFile(
+            'optionalPropertySerialization.json',
+            (new GeneratorConfiguration())->setSerialization(true)
+        );
+
+        $object = new $className(['property1' => 'Hello']);
+
+        $this->assertEqualsCanonicalizing(
+            ['property1' => 'Hello', 'property2' => null, 'property3' => 'Moin'],
+            $object->toArray()
+        );
+    }
+
+    public function testSerializeSkipsNotProvidedOptionalProperties(): void
+    {
+        $className = $this->generateClassFromFile(
+            'optionalPropertySerialization.json',
+            (new GeneratorConfiguration())->setSerialization(true)->setImmutable(false),
+            false,
+            false
+        );
+
+        $object = new $className(['property1' => 'Hello']);
+
+        $this->assertEqualsCanonicalizing(['property1' => 'Hello', 'property3' => 'Moin'], $object->toArray());
+        $object->setProperty2('World');
+        $this->assertEqualsCanonicalizing(
+            ['property1' => 'Hello', 'property2' => 'World', 'property3' => 'Moin'],
+            $object->toArray()
+        );
+    }
+}

tests/Schema/Issues/76/optionalPropertySerialization.json

@@ -0,0 +1,18 @@
+{
+  "type": "object",
+  "properties": {
+    "property1": {
+      "type": "string"
+    },
+    "property2": {
+      "type": "string"
+    },
+    "property3": {
+      "type": "string",
+      "default": "Moin"
+    }
+  },
+  "required": [
+    "property1"
+  ]
+}