Nullable values

src/Formatter/ArrayBasedDeformatter.php

@@ -24,14 +24,16 @@
  */
 trait ArrayBasedDeformatter
 {
-    public function deserializeInt(mixed $decoded, Field $field): int|DeformatterResult
+    public function deserializeInt(mixed $decoded, Field $field): int|DeformatterResult|null
     {
-        if (!isset($decoded[$field->serializedName])) {
+        if (!array_key_exists($field->serializedName, $decoded)) {
             return DeformatterResult::Missing;
         }
 
+        $value = $decoded[$field->serializedName];
+
         if ($field->strict) {
-            if (!is_int($decoded[$field->serializedName])) {
+            if (!is_int($value) && !($field->nullable && is_null($value))) {
                 throw TypeMismatch::create($field->serializedName, 'int', \get_debug_type($decoded[$field->serializedName]));
             }
             return $decoded[$field->serializedName];
@@ -41,14 +43,16 @@ public function deserializeInt(mixed $decoded, Field $field): int|DeformatterRes
         return (int)($decoded[$field->serializedName]);
     }
 
-    public function deserializeFloat(mixed $decoded, Field $field): float|DeformatterResult
+    public function deserializeFloat(mixed $decoded, Field $field): float|DeformatterResult|null
     {
-        if (!isset($decoded[$field->serializedName])) {
+        if (!array_key_exists($field->serializedName, $decoded)) {
             return DeformatterResult::Missing;
         }
 
+        $value = $decoded[$field->serializedName];
+
         if ($field->strict) {
-            if (!(is_float($decoded[$field->serializedName]) || is_int($decoded[$field->serializedName]))) {
+            if (!is_int($value) && !is_float($value) && !($field->nullable && is_null($value))) {
                 throw TypeMismatch::create($field->serializedName, 'float', \get_debug_type($decoded[$field->serializedName]));
             }
             return $decoded[$field->serializedName];
@@ -58,14 +62,16 @@ public function deserializeFloat(mixed $decoded, Field $field): float|Deformatte
         return (float)($decoded[$field->serializedName]);
     }
 
-    public function deserializeBool(mixed $decoded, Field $field): bool|DeformatterResult
+    public function deserializeBool(mixed $decoded, Field $field): bool|DeformatterResult|null
     {
-        if (!isset($decoded[$field->serializedName])) {
+        if (!array_key_exists($field->serializedName, $decoded)) {
             return DeformatterResult::Missing;
         }
 
+        $value = $decoded[$field->serializedName];
+
         if ($field->strict) {
-            if (!is_bool($decoded[$field->serializedName])) {
+            if (!is_bool($value) && !($field->nullable && is_null($value))) {
                 throw TypeMismatch::create($field->serializedName, 'bool', \get_debug_type($decoded[$field->serializedName]));
             }
             return $decoded[$field->serializedName];
@@ -75,21 +81,23 @@ public function deserializeBool(mixed $decoded, Field $field): bool|DeformatterR
         return (bool)($decoded[$field->serializedName]);
     }
 
-    public function deserializeString(mixed $decoded, Field $field): string|DeformatterResult
+    public function deserializeString(mixed $decoded, Field $field): string|DeformatterResult|null
     {
-        if (!isset($decoded[$field->serializedName])) {
+        if (!array_key_exists($field->serializedName, $decoded)) {
             return DeformatterResult::Missing;
         }
 
+        $value = $decoded[$field->serializedName];
+
         if ($field->strict) {
-            if (!is_string($decoded[$field->serializedName])) {
-                throw TypeMismatch::create($field->serializedName, 'string', \get_debug_type($decoded[$field->serializedName]));
+            if (!is_string($value) && !($field->nullable && is_null($value))) {
+                throw TypeMismatch::create($field->serializedName, 'string', \get_debug_type($value));
             }
-            return $decoded[$field->serializedName];
+            return $value;
         }
 
         // Weak mode.
-        return (string)($decoded[$field->serializedName]);
+        return (string)($value);
     }
 
     public function deserializeNull(mixed $decoded, Field $field): ?DeformatterResult
@@ -211,15 +219,15 @@ protected function upcastArray(array $data, Deserializer $deserializer, ?string
      * @param Deserializer $deserializer
      * @return array<string, mixed>|DeformatterResult
      */
-    public function deserializeObject(mixed $decoded, Field $field, Deserializer $deserializer): array|DeformatterResult
+    public function deserializeObject(mixed $decoded, Field $field, Deserializer $deserializer): array|DeformatterResult|null
     {
         $candidateNames = [$field->serializedName, ...$field->alias];
 
         $key = pipe($candidateNames,
             first(static fn (string $name): bool => isset($decoded[$name]))
         );
 
-        if (!isset($decoded[$key])) {
+        if (!array_key_exists($key, $decoded)) {
             return DeformatterResult::Missing;
         }
 
@@ -252,7 +260,7 @@ public function deserializeObject(mixed $decoded, Field $field, Deserializer $de
             } else {
                 $key = pipe(
                     $propField->alias,
-                    first(fn(string $name): bool => isset($data[$name])),
+                    first(fn(string $name): bool => array_key_exists($name, $data)),
                 );
                 $ret[$propField->serializedName] = $key
                     ? $deserializer->deserialize($data, $propField->with(serializedName: $key))

src/Formatter/Deformatter.php

@@ -31,15 +31,15 @@ public function deserializeInitialize(
         Deserializer $deserializer
     ): mixed;
 
-    public function deserializeInt(mixed $decoded, Field $field): int|DeformatterResult;
+    public function deserializeInt(mixed $decoded, Field $field): int|DeformatterResult|null;
 
-    public function deserializeFloat(mixed $decoded, Field $field): float|DeformatterResult;
+    public function deserializeFloat(mixed $decoded, Field $field): float|DeformatterResult|null;
 
-    public function deserializeBool(mixed $decoded, Field $field): bool|DeformatterResult;
+    public function deserializeBool(mixed $decoded, Field $field): bool|DeformatterResult|null;
 
-    public function deserializeString(mixed $decoded, Field $field): string|DeformatterResult;
+    public function deserializeString(mixed $decoded, Field $field): string|DeformatterResult|null;
 
-    public function deserializeNull(mixed $decoded, Field $field): ?DeformatterResult;
+    public function deserializeNull(mixed $decoded, Field $field): DeformatterResult|null;
 
     /**
      * @param mixed $decoded
@@ -61,9 +61,9 @@ public function deserializeDictionary(mixed $decoded, Field $field, Deserializer
      * @param mixed $decoded
      * @param Field $field
      * @param Deserializer $deserializer
-     * @return array<string, mixed>|DeformatterResult
+     * @return array<string, mixed>|DeformatterResult|null
      */
-    public function deserializeObject( mixed $decoded, Field $field, Deserializer $deserializer): array|DeformatterResult;
+    public function deserializeObject( mixed $decoded, Field $field, Deserializer $deserializer): array|DeformatterResult|null;
 
     public function deserializeFinalize(mixed $decoded): void;
 }

src/PropertyHandler/DateTimeExporter.php

@@ -50,7 +50,7 @@ public function importValue(Deserializer $deserializer, Field $field, mixed $sou
     {
         $string = $deserializer->deformatter->deserializeString($source, $field);
 
-        if ($string === DeformatterResult::Missing) {
+        if ($string === DeformatterResult::Missing || $string === null) {
             return null;
         }
 

src/PropertyHandler/DateTimeZoneExporter.php

@@ -33,7 +33,7 @@ public function importValue(Deserializer $deserializer, Field $field, mixed $sou
     {
         $string = $deserializer->deformatter->deserializeString($source, $field);
 
-        if ($string instanceof DeformatterResult) {
+        if ($string instanceof DeformatterResult || $string === null) {
             return null;
         }
 

src/PropertyHandler/DictionaryExporter.php

@@ -104,7 +104,7 @@ public function importValue(Deserializer $deserializer, Field $field, mixed $sou
         // We cannot easily tell them apart at the moment.
         if ($typeField instanceof DictionaryField && $typeField->implodeOn) {
             $val = $deserializer->deformatter->deserializeString($source, $field);
-            return $val === DeformatterResult::Missing ? null : $typeField->explode($val);
+            return $val === DeformatterResult::Missing || $val === null ? null : $typeField->explode($val);
         }
 
         return $deserializer->deformatter->deserializeDictionary($source, $field, $deserializer);

src/PropertyHandler/ObjectImporter.php

@@ -23,7 +23,7 @@ public function importValue(Deserializer $deserializer, Field $field, mixed $sou
         // Get the raw data as an array from the source.
         $dict = $deserializer->deformatter->deserializeObject($source, $field, $deserializer);
 
-        if ($dict instanceof DeformatterResult) {
+        if ($dict instanceof DeformatterResult || $dict === null) {
             return null;
         }
 

src/PropertyHandler/SequenceExporter.php

@@ -76,7 +76,7 @@ public function importValue(Deserializer $deserializer, Field $field, mixed $sou
         // We cannot easily tell them apart at the moment.
         if ($typeField instanceof SequenceField && $typeField->implodeOn) {
             $val = $deserializer->deformatter->deserializeString($source, $field);
-            return $val === DeformatterResult::Missing ? null : $typeField->explode($val);
+            return $val === DeformatterResult::Missing || $val === null ? null : $typeField->explode($val);
         }
 
         return $deserializer->deformatter->deserializeSequence($source, $field, $deserializer);

tests/ArrayBasedFormatterTestCases.php

@@ -144,6 +144,7 @@ protected function empty_values_validate(mixed $serialized): void
 
         self::assertEquals('narf', $toTest['nonConstructorDefault']);
         self::assertEquals('beep', $toTest['required']);
+        self::assertNull($toTest['requiredNullable']);
         self::assertEquals('boop', $toTest['withDefault']);
         self::assertArrayNotHasKey('nullableUninitialized', $toTest);
         self::assertArrayNotHasKey('uninitialized', $toTest);
@@ -427,7 +428,7 @@ public function class_level_renaming_applies_validate(mixed $serialized): void
         self::assertArrayHasKey('the_number', $toTest);
     }
 
-    public function null_stuff_validate(mixed $serialized): void
+    public function null_properties_are_allowed_validate(mixed $serialized): void
     {
         $toTest = $this->arrayify($serialized);
 

tests/Records/EmptyData.php

@@ -16,6 +16,7 @@ class EmptyData
 
     public function __construct(
         public string $required,
+        public ?string $requiredNullable,
         public string $withDefault = 'boop',
         public ?string $nullable = null,
         public readonly ?string $roNullable = null,

tests/SerdeTestCases.php

@@ -611,7 +611,7 @@ public function empty_values(): void
     {
         $s = new SerdeCommon(formatters: $this->formatters);
 
-        $data = new EmptyData('beep');
+        $data = new EmptyData('beep', null);
 
         $serialized = $s->serialize($data, $this->format);