Improve internal type safety

src/Meta/MetaResolver.php

@@ -39,8 +39,11 @@
 use Reflector;
 use function array_key_exists;
 use function array_merge;
+use function assert;
 use function get_class;
 use function is_a;
+use function is_int;
+use function is_string;
 use const PHP_VERSION_ID;
 
 /**
@@ -487,6 +490,7 @@ private function checkFieldNames(ReflectionClass $rootClass, CompileMeta $meta):
 			foreach ($fieldMeta->getModifiers() as $modifier) {
 				if ($modifier->getType() === FieldNameModifier::class) {
 					$fieldName = $modifier->getArgs()[FieldNameModifier::Name];
+					assert(is_string($fieldName) || is_int($fieldName));
 
 					break;
 				}

src/Printers/ErrorVisualPrinter.php

@@ -16,7 +16,7 @@
 use function get_class;
 
 /**
- * @template T of string|array
+ * @template T of string|array<mixed>
  */
 final class ErrorVisualPrinter implements ErrorPrinter, TypePrinter
 {
@@ -25,7 +25,7 @@ final class ErrorVisualPrinter implements ErrorPrinter, TypePrinter
 	private TypeToPrimitiveConverter $converter;
 
 	/**
-	 * @param TypeToPrimitiveConverter<T> $converter
+	 * @param TypeToPrimitiveConverter<covariant T> $converter
 	 */
 	public function __construct(TypeToPrimitiveConverter $converter)
 	{

src/Printers/TypeToPrimitiveConverter.php

@@ -6,7 +6,7 @@
 use Orisai\ObjectMapper\Types\TypeParameter;
 
 /**
- * @template T of string|array
+ * @template T of string|array<mixed>
  */
 interface TypeToPrimitiveConverter
 {

src/Rules/ArrayOfRule.php

@@ -15,9 +15,12 @@
 use Orisai\ObjectMapper\Processing\Value;
 use Orisai\ObjectMapper\Types\GenericArrayType;
 use Orisai\Utils\Arrays\ArrayMerger;
+use function assert;
 use function count;
 use function get_debug_type;
 use function is_array;
+use function is_int;
+use function is_string;
 use function sprintf;
 
 /**
@@ -159,6 +162,7 @@ public function processValue(
 						$property,
 						$dynamic->createClone(),
 					);
+					assert(is_int($key) || is_string($key));
 				} catch (ValueDoesNotMatch | InvalidData $exception) {
 					$type ??= $this->createType($args, $services, $dynamic);
 					$type->addInvalidKey($key, $exception);
@@ -221,7 +225,9 @@ public function processValue(
 		}
 
 		if ($args->mergeDefaults && $property->hasDefaultValue()) {
-			$value = ArrayMerger::merge($property->getDefaultValue(), $value);
+			$default = $property->getDefaultValue();
+			assert(is_array($default)); // Rule validates that default is an array
+			$value = ArrayMerger::merge($default, $value);
 		}
 
 		return $value;

src/Rules/ListOfRule.php

@@ -2,6 +2,7 @@
 
 namespace Orisai\ObjectMapper\Rules;
 
+use Orisai\Exceptions\Logic\InvalidArgument;
 use Orisai\ObjectMapper\Args\Args;
 use Orisai\ObjectMapper\Args\ArgsChecker;
 use Orisai\ObjectMapper\Exception\InvalidData;
@@ -15,9 +16,12 @@
 use Orisai\ObjectMapper\Types\GenericArrayType;
 use Orisai\ObjectMapper\Types\SimpleValueType;
 use Orisai\Utils\Arrays\ArrayMerger;
+use function assert;
 use function count;
+use function get_debug_type;
 use function is_array;
 use function is_int;
+use function sprintf;
 
 /**
  * @extends MultiValueRule<MultiValueArgs>
@@ -54,6 +58,20 @@ public function resolveArgs(array $args, MetaFieldContext $context): MultiValueA
 			$mergeDefaults = $checker->checkBool(self::MergeDefaults);
 		}
 
+		if (
+			$mergeDefaults
+			&& $context->hasDefaultValue()
+			&& !is_array($defaultValue = $context->getDefaultValue())
+		) {
+			throw InvalidArgument::create()
+				->withMessage(sprintf(
+					'Argument "%s" given to "%s" is set to true but the default value is "%s" insteadof an array.',
+					self::MergeDefaults,
+					self::class,
+					get_debug_type($defaultValue),
+				));
+		}
+
 		return new MultiValueArgs(
 			$itemRuleMeta,
 			$minItems,
@@ -186,7 +204,9 @@ public function processValue(
 		}
 
 		if ($args->mergeDefaults && $property->hasDefaultValue()) {
-			$value = ArrayMerger::merge($property->getDefaultValue(), $value);
+			$default = $property->getDefaultValue();
+			assert(is_array($default)); // Rule validates that default is an array
+			$value = ArrayMerger::merge($default, $value);
 		}
 
 		return $value;

tests/Doubles/Callbacks/CallbacksVO.php

@@ -14,6 +14,7 @@
 use Orisai\ObjectMapper\Rules\MixedValue;
 use Orisai\ObjectMapper\Rules\StringValue;
 use function array_key_exists;
+use function assert;
 use function is_array;
 
 /**
@@ -75,6 +76,8 @@ public static function beforeClass($data, ObjectContext $context)
 			return $data;
 		}
 
+		assert(is_array($data['array']));
+		assert(is_array($data['array']['beforeClassCallback']));
 		$data['array']['beforeClassCallback'][] = $context->shouldInitializeObjects();
 
 		// Set default value, processor don't know it's going to be structure and thinks value is required
@@ -97,6 +100,8 @@ public static function beforeClass($data, ObjectContext $context)
 	 */
 	public static function afterClass(array $data, ObjectContext $context): array
 	{
+		assert(is_array($data['array']));
+		assert(is_array($data['array']['afterClassCallback']));
 		$data['array']['afterClassCallback'][] = $context->shouldInitializeObjects();
 
 		if ($context->shouldInitializeObjects() && !$data['structure'] instanceof MappedObject) {
@@ -118,6 +123,7 @@ public static function afterClass(array $data, ObjectContext $context): array
 	 */
 	public static function afterArrayProcessing(array $array, FieldContext $context): array
 	{
+		assert(is_array($array['afterArrayProcessingCallback']));
 		$array['afterArrayProcessingCallback'][] = $context->shouldInitializeObjects();
 
 		return $array;
@@ -129,6 +135,7 @@ public static function afterArrayProcessing(array $array, FieldContext $context)
 	 */
 	public static function afterArrayInitialization(array $array, FieldContext $context): array
 	{
+		assert(is_array($array['afterArrayInitializationCallback']));
 		$array['afterArrayInitializationCallback'][] = $context->shouldInitializeObjects();
 
 		return $array;

tests/Doubles/Inheritance/trait-callback.php

@@ -6,6 +6,7 @@
 use Orisai\ObjectMapper\Callbacks\Before;
 use Orisai\ObjectMapper\MappedObject;
 use Orisai\ObjectMapper\Rules\StringValue;
+use function assert;
 use function is_array;
 use function is_string;
 
@@ -42,6 +43,7 @@ private function before($data)
 	 */
 	private function after(array $data): array
 	{
+		assert(is_string($data['string']));
 		$data['string'] .= '-A::after';
 
 		return $data;

tests/Unit/Processing/RawValuesMapTest.php

@@ -6,6 +6,7 @@
 use Orisai\ObjectMapper\Processing\RawValuesMap;
 use PHPUnit\Framework\TestCase;
 use Tests\Orisai\ObjectMapper\Doubles\DefaultsVO;
+use function assert;
 use function serialize;
 use function unserialize;
 use const PHP_VERSION_ID;
@@ -58,6 +59,7 @@ public function testUnset(): void
 		$data = serialize($object);
 		unset($object);
 		$object = unserialize($data);
+		assert($object instanceof DefaultsVO);
 
 		$this->expectException(InvalidState::class);
 		$map->getRawValues($object);

tests/Unit/Rules/BackedEnumRuleTest.php

@@ -8,6 +8,7 @@
 use Orisai\ObjectMapper\Rules\BackedEnumArgs;
 use Orisai\ObjectMapper\Rules\BackedEnumRule;
 use Orisai\ObjectMapper\Types\EnumType;
+use stdClass;
 use Tests\Orisai\ObjectMapper\Doubles\Php81\ExampleIntEnum;
 use Tests\Orisai\ObjectMapper\Doubles\Php81\ExampleStringEnum;
 use Tests\Orisai\ObjectMapper\Toolkit\ProcessingTestCase;
@@ -148,6 +149,18 @@ public function provideInvalidValues(): Generator
 			new BackedEnumArgs(ExampleIntEnum::class, false),
 			[0, 1],
 		];
+
+		yield [
+			['foo', 'bar'],
+			new BackedEnumArgs(ExampleIntEnum::class, false),
+			[0, 1],
+		];
+
+		yield [
+			new stdClass(),
+			new BackedEnumArgs(ExampleIntEnum::class, false),
+			[0, 1],
+		];
 	}
 
 	public function testType(): void

tests/Unit/Rules/DateTimeRuleTest.php

@@ -116,8 +116,8 @@ public function provideValidValues(): Generator
 	}
 
 	/**
-	 * @param mixed              $value
-	 * @param array<int, string> $invalidParameters
+	 * @param mixed $value
+	 * @param list<int|string|array<int|string, mixed>> $invalidParameters
 	 *
 	 * @dataProvider provideInvalidValues
 	 */
@@ -148,12 +148,9 @@ public function testProcessInvalid(
 			$parameters = [];
 			foreach ($type->getParameters() as $parameter) {
 				if ($parameter->isInvalid()) {
-					$parameterString = $parameter->getKey();
-					if ($parameter->hasValue()) {
-						$parameterString .= ": {$parameter->getValue()}";
-					}
-
-					$parameters[] = $parameterString;
+					$parameters[] = $parameter->hasValue()
+						? [$parameter->getKey(), $parameter->getValue()]
+						: $parameter->getKey();
 				}
 			}
 
@@ -177,7 +174,7 @@ public function provideInvalidValues(): Generator
 		]];
 
 		yield ['whatever', DateTimeInterface::ATOM, [
-			'format: Y-m-d\TH:i:sP',
+			['format', 'Y-m-d\TH:i:sP'],
 			'A four digit year could not be found',
 			PHP_VERSION_ID < 8_01_07 ? 'Data missing' : 'Not enough data available to satisfy format',
 		]];
@@ -187,7 +184,7 @@ public function provideInvalidValues(): Generator
 		], 'timestamp'];
 
 		yield ['2013-04-12T16:40:00-04:00', DateTimeInterface::COOKIE, [
-			'format: l, d-M-Y H:i:s T',
+			['format', 'l, d-M-Y H:i:s T'],
 			'A textual day could not be found',
 			'Unexpected data found.',
 			'The separation symbol could not be found',

tools/phpstan.baseline.neon

@@ -1,5 +1,11 @@
 parameters:
 	ignoreErrors:
+		-
+			message: '#^Property Orisai\\ObjectMapper\\Printers\\ErrorVisualPrinter\<T of array\<mixed\>\|string\>\:\:\$converter \(Orisai\\ObjectMapper\\Printers\\TypeToPrimitiveConverter\<T of array\<mixed\>\|string\>\) does not accept Orisai\\ObjectMapper\\Printers\\TypeToPrimitiveConverter\<covariant T of array\<mixed\>\|string\>\.$#'
+			identifier: assign.propertyType
+			count: 1
+			path: ../src/Printers/ErrorVisualPrinter.php
+
 		-
 			message: '#^Unreachable statement \- code above always terminates\.$#'
 			identifier: deadCode.unreachable