Refactor TryRemove/Accepts for DateTime|DateTimeImmutable and Exception|Error

Author: VincentLanglet

phpstan-baseline.neon

@@ -1422,7 +1422,7 @@ parameters:
 		-
 			message: '#^Doing instanceof PHPStan\\Type\\ObjectType is error\-prone and deprecated\. Use Type\:\:isObject\(\) or Type\:\:getObjectClassNames\(\) instead\.$#'
 			identifier: phpstanApi.instanceofType
-			count: 6
+			count: 3
 			path: src/Type/ObjectType.php
 
 		-

src/Type/ObjectType.php

@@ -5,11 +5,6 @@
 use ArrayAccess;
 use Closure;
 use Countable;
-use DateTime;
-use DateTimeImmutable;
-use DateTimeInterface;
-use Error;
-use Exception;
 use Iterator;
 use IteratorAggregate;
 use PHPStan\Analyser\OutOfClassScope;
@@ -46,7 +41,6 @@
 use PHPStan\Type\Traits\NonGeneralizableTypeTrait;
 use PHPStan\Type\Traits\NonGenericTypeTrait;
 use PHPStan\Type\Traits\UndecidedComparisonTypeTrait;
-use Throwable;
 use Traversable;
 use function array_key_exists;
 use function array_map;
@@ -1560,23 +1554,21 @@ private function getInterfaces(): array
 
 	public function tryRemove(Type $typeToRemove): ?Type
 	{
-		if ($this->getClassName() === DateTimeInterface::class) {
-			if ($typeToRemove instanceof ObjectType && $typeToRemove->getClassName() === DateTimeImmutable::class) {
-				return new ObjectType(DateTime::class);
-			}
-
-			if ($typeToRemove instanceof ObjectType && $typeToRemove->getClassName() === DateTime::class) {
-				return new ObjectType(DateTimeImmutable::class);
-			}
-		}
+		if ($typeToRemove instanceof ObjectType) {
+			foreach (UnionType::EQUAL_UNION_CLASSES as $baseClass => $classes) {
+				if ($this->getClassName() !== $baseClass) {
+					continue;
+				}
 
-		if ($this->getClassName() === Throwable::class) {
-			if ($typeToRemove instanceof ObjectType && $typeToRemove->getClassName() === Error::class) {
-				return new ObjectType(Exception::class); // phpcs:ignore SlevomatCodingStandard.Exceptions.ReferenceThrowableOnly.ReferencedGeneralException
-			}
+				foreach ($classes as $index => $class) {
+					if ($typeToRemove->getClassName() === $class) {
+						unset($classes[$index]);
 
-			if ($typeToRemove instanceof ObjectType && $typeToRemove->getClassName() === Exception::class) { // phpcs:ignore SlevomatCodingStandard.Exceptions.ReferenceThrowableOnly.ReferencedGeneralException
-				return new ObjectType(Error::class);
+						return TypeCombinator::union(
+							...array_map(static fn (string $objectClass): Type => new ObjectType($objectClass), $classes),
+						);
+					}
+				}
 			}
 		}
 

src/Type/UnionType.php

@@ -5,6 +5,8 @@
 use DateTime;
 use DateTimeImmutable;
 use DateTimeInterface;
+use Error;
+use Exception;
 use PHPStan\Php\PhpVersion;
 use PHPStan\PhpDocParser\Ast\Type\TypeNode;
 use PHPStan\PhpDocParser\Ast\Type\UnionTypeNode;
@@ -26,6 +28,7 @@
 use PHPStan\Type\Generic\TemplateTypeVariance;
 use PHPStan\Type\Generic\TemplateUnionType;
 use PHPStan\Type\Traits\NonGeneralizableTypeTrait;
+use Throwable;
 use function array_diff_assoc;
 use function array_fill_keys;
 use function array_map;
@@ -45,6 +48,11 @@ class UnionType implements CompoundType
 
 	use NonGeneralizableTypeTrait;
 
+	public const EQUAL_UNION_CLASSES = [
+		DateTimeInterface::class => [DateTimeImmutable::class, DateTime::class],
+		Throwable::class => [Error::class, Exception::class], // phpcs:ignore SlevomatCodingStandard.Exceptions.ReferenceThrowableOnly.ReferencedGeneralException
+	];
+
 	private bool $sortedTypes = false;
 
 	/** @var array<int, string> */
@@ -183,14 +191,18 @@ public function getConstantStrings(): array
 
 	public function accepts(Type $type, bool $strictTypes): AcceptsResult
 	{
-		if (
-			$type->equals(new ObjectType(DateTimeInterface::class))
-			&& $this->accepts(
-				new UnionType([new ObjectType(DateTime::class), new ObjectType(DateTimeImmutable::class)]),
-				$strictTypes,
-			)->yes()
-		) {
-			return AcceptsResult::createYes();
+		foreach (self::EQUAL_UNION_CLASSES as $baseClass => $classes) {
+			if (!$type->equals(new ObjectType($baseClass))) {
+				continue;
+			}
+
+			$union = TypeCombinator::union(
+				...array_map(static fn (string $objectClass): Type => new ObjectType($objectClass), $classes),
+			);
+			if ($this->accepts($union, $strictTypes)->yes()) {
+				return AcceptsResult::createYes();
+			}
+			break;
 		}
 
 		$result = AcceptsResult::createNo();