Implement Type->getEnumCaseObject()

src/Type/Accessory/HasMethodType.php

@@ -13,6 +13,7 @@
 use PHPStan\TrinaryLogic;
 use PHPStan\Type\AcceptsResult;
 use PHPStan\Type\CompoundType;
+use PHPStan\Type\Enum\EnumCaseObjectType;
 use PHPStan\Type\ErrorType;
 use PHPStan\Type\IntersectionType;
 use PHPStan\Type\IsSuperTypeOfResult;
@@ -166,6 +167,11 @@ public function getEnumCases(): array
 		return [];
 	}
 
+	public function getEnumCaseObject(): ?EnumCaseObjectType
+	{
+		return null;
+	}
+
 	public function traverse(callable $cb): Type
 	{
 		return $this;

src/Type/Accessory/HasOffsetType.php

@@ -11,6 +11,7 @@
 use PHPStan\Type\CompoundType;
 use PHPStan\Type\Constant\ConstantIntegerType;
 use PHPStan\Type\Constant\ConstantStringType;
+use PHPStan\Type\Enum\EnumCaseObjectType;
 use PHPStan\Type\ErrorType;
 use PHPStan\Type\IntegerRangeType;
 use PHPStan\Type\IntersectionType;
@@ -412,6 +413,11 @@ public function getEnumCases(): array
 		return [];
 	}
 
+	public function getEnumCaseObject(): ?EnumCaseObjectType
+	{
+		return null;
+	}
+
 	public function traverse(callable $cb): Type
 	{
 		return $this;

src/Type/Accessory/HasOffsetValueType.php

@@ -13,6 +13,7 @@
 use PHPStan\Type\Constant\ConstantIntegerType;
 use PHPStan\Type\Constant\ConstantStringType;
 use PHPStan\Type\ConstantScalarType;
+use PHPStan\Type\Enum\EnumCaseObjectType;
 use PHPStan\Type\ErrorType;
 use PHPStan\Type\IntegerRangeType;
 use PHPStan\Type\IntegerType;
@@ -476,6 +477,11 @@ public function getEnumCases(): array
 		return [];
 	}
 
+	public function getEnumCaseObject(): ?EnumCaseObjectType
+	{
+		return null;
+	}
+
 	public function traverse(callable $cb): Type
 	{
 		$newValueType = $cb($this->valueType);

src/Type/Accessory/HasPropertyType.php

@@ -9,6 +9,7 @@
 use PHPStan\TrinaryLogic;
 use PHPStan\Type\AcceptsResult;
 use PHPStan\Type\CompoundType;
+use PHPStan\Type\Enum\EnumCaseObjectType;
 use PHPStan\Type\ErrorType;
 use PHPStan\Type\IntersectionType;
 use PHPStan\Type\IsSuperTypeOfResult;
@@ -149,6 +150,11 @@ public function getEnumCases(): array
 		return [];
 	}
 
+	public function getEnumCaseObject(): ?EnumCaseObjectType
+	{
+		return null;
+	}
+
 	public function traverse(callable $cb): Type
 	{
 		return $this;

src/Type/CallableType.php

@@ -26,6 +26,7 @@
 use PHPStan\ShouldNotHappenException;
 use PHPStan\TrinaryLogic;
 use PHPStan\Type\Accessory\AccessoryNonEmptyStringType;
+use PHPStan\Type\Enum\EnumCaseObjectType;
 use PHPStan\Type\Generic\TemplateType;
 use PHPStan\Type\Generic\TemplateTypeHelper;
 use PHPStan\Type\Generic\TemplateTypeMap;
@@ -645,6 +646,11 @@ public function getEnumCases(): array
 		return [];
 	}
 
+	public function getEnumCaseObject(): ?EnumCaseObjectType
+	{
+		return null;
+	}
+
 	public function isCommonCallable(): bool
 	{
 		return $this->isCommonCallable;

src/Type/ClosureType.php

@@ -35,6 +35,7 @@
 use PHPStan\Type\Constant\ConstantArrayType;
 use PHPStan\Type\Constant\ConstantBooleanType;
 use PHPStan\Type\Constant\ConstantIntegerType;
+use PHPStan\Type\Enum\EnumCaseObjectType;
 use PHPStan\Type\Generic\TemplateType;
 use PHPStan\Type\Generic\TemplateTypeHelper;
 use PHPStan\Type\Generic\TemplateTypeMap;
@@ -423,6 +424,11 @@ public function getEnumCases(): array
 		return [];
 	}
 
+	public function getEnumCaseObject(): ?EnumCaseObjectType
+	{
+		return null;
+	}
+
 	public function isCommonCallable(): bool
 	{
 		return $this->isCommonCallable;

src/Type/Enum/EnumCaseObjectType.php

@@ -217,6 +217,11 @@ public function getEnumCases(): array
 		return [$this];
 	}
 
+	public function getEnumCaseObject(): ?EnumCaseObjectType
+	{
+		return $this;
+	}
+
 	public function toPhpDocNode(): TypeNode
 	{
 		return new ConstTypeNode(

src/Type/IntersectionType.php

@@ -37,6 +37,7 @@
 use PHPStan\Type\Constant\ConstantArrayType;
 use PHPStan\Type\Constant\ConstantIntegerType;
 use PHPStan\Type\Constant\ConstantStringType;
+use PHPStan\Type\Enum\EnumCaseObjectType;
 use PHPStan\Type\Generic\TemplateType;
 use PHPStan\Type\Generic\TemplateTypeMap;
 use PHPStan\Type\Generic\TemplateTypeVariance;
@@ -1032,6 +1033,25 @@ public function getEnumCases(): array
 		return array_values(array_intersect_key(...$compare));
 	}
 
+	public function getEnumCaseObject(): ?EnumCaseObjectType
+	{
+		$singleCase = null;
+		foreach ($this->types as $type) {
+			$caseObject = $type->getEnumCaseObject();
+			if ($caseObject === null) {
+				continue;
+			}
+
+			if ($singleCase !== null) {
+				return null;
+			}
+
+			$singleCase = $caseObject;
+		}
+
+		return $singleCase;
+	}
+
 	public function isCallable(): TrinaryLogic
 	{
 		return $this->intersectResults(static fn (Type $type): TrinaryLogic => $type->isCallable());

src/Type/IterableType.php

@@ -7,6 +7,7 @@
 use PHPStan\PhpDocParser\Ast\Type\IdentifierTypeNode;
 use PHPStan\PhpDocParser\Ast\Type\TypeNode;
 use PHPStan\TrinaryLogic;
+use PHPStan\Type\Enum\EnumCaseObjectType;
 use PHPStan\Type\Generic\GenericObjectType;
 use PHPStan\Type\Generic\TemplateMixedType;
 use PHPStan\Type\Generic\TemplateTypeMap;
@@ -421,6 +422,11 @@ public function getEnumCases(): array
 		return [];
 	}
 
+	public function getEnumCaseObject(): ?EnumCaseObjectType
+	{
+		return null;
+	}
+
 	public function inferTemplateTypes(Type $receivedType): TemplateTypeMap
 	{
 		if ($receivedType instanceof UnionType || $receivedType instanceof IntersectionType) {

src/Type/MixedType.php

@@ -32,6 +32,7 @@
 use PHPStan\Type\Constant\ConstantFloatType;
 use PHPStan\Type\Constant\ConstantIntegerType;
 use PHPStan\Type\Constant\ConstantStringType;
+use PHPStan\Type\Enum\EnumCaseObjectType;
 use PHPStan\Type\Generic\TemplateMixedType;
 use PHPStan\Type\Generic\TemplateType;
 use PHPStan\Type\Traits\NonGeneralizableTypeTrait;
@@ -320,6 +321,11 @@ public function getEnumCases(): array
 		return [];
 	}
 
+	public function getEnumCaseObject(): ?EnumCaseObjectType
+	{
+		return null;
+	}
+
 	public function getCallableParametersAcceptors(ClassMemberAccessAnswerer $scope): array
 	{
 		return [new TrivialParametersAcceptor()];

src/Type/NeverType.php

@@ -13,6 +13,7 @@
 use PHPStan\Reflection\Type\UnresolvedPropertyPrototypeReflection;
 use PHPStan\ShouldNotHappenException;
 use PHPStan\TrinaryLogic;
+use PHPStan\Type\Enum\EnumCaseObjectType;
 use PHPStan\Type\Traits\NonGeneralizableTypeTrait;
 use PHPStan\Type\Traits\NonGenericTypeTrait;
 use PHPStan\Type\Traits\NonRemoveableTypeTrait;
@@ -558,6 +559,11 @@ public function getEnumCases(): array
 		return [];
 	}
 
+	public function getEnumCaseObject(): ?EnumCaseObjectType
+	{
+		return null;
+	}
+
 	public function exponentiate(Type $exponent): Type
 	{
 		return $this;

src/Type/NonexistentParentClassType.php

@@ -13,6 +13,7 @@
 use PHPStan\Reflection\Type\UnresolvedPropertyPrototypeReflection;
 use PHPStan\ShouldNotHappenException;
 use PHPStan\TrinaryLogic;
+use PHPStan\Type\Enum\EnumCaseObjectType;
 use PHPStan\Type\Traits\NonArrayTypeTrait;
 use PHPStan\Type\Traits\NonCallableTypeTrait;
 use PHPStan\Type\Traits\NonGeneralizableTypeTrait;
@@ -212,6 +213,11 @@ public function getEnumCases(): array
 		return [];
 	}
 
+	public function getEnumCaseObject(): ?EnumCaseObjectType
+	{
+		return null;
+	}
+
 	public function exponentiate(Type $exponent): Type
 	{
 		return new ErrorType();

src/Type/ObjectShapeType.php

@@ -21,6 +21,7 @@
 use PHPStan\Type\Accessory\HasPropertyType;
 use PHPStan\Type\Constant\ConstantArrayType;
 use PHPStan\Type\Constant\ConstantStringType;
+use PHPStan\Type\Enum\EnumCaseObjectType;
 use PHPStan\Type\Generic\TemplateTypeMap;
 use PHPStan\Type\Generic\TemplateTypeVariance;
 use PHPStan\Type\Traits\NonGeneralizableTypeTrait;
@@ -463,6 +464,11 @@ public function getEnumCases(): array
 		return [];
 	}
 
+	public function getEnumCaseObject(): ?EnumCaseObjectType
+	{
+		return null;
+	}
+
 	public function traverse(callable $cb): Type
 	{
 		$properties = [];

src/Type/ObjectType.php

@@ -1516,6 +1516,17 @@ public function getEnumCases(): array
 		return self::$enumCases[$cacheKey] = $cases;
 	}
 
+	public function getEnumCaseObject(): ?EnumCaseObjectType
+	{
+		$cases = $this->getEnumCases();
+
+		if (count($cases) === 1) {
+			return $cases[0];
+		}
+
+		return null;
+	}
+
 	public function isCallable(): TrinaryLogic
 	{
 		$parametersAcceptors = RecursionGuard::run($this, fn () => $this->findCallableParametersAcceptors());

src/Type/ObjectWithoutClassType.php

@@ -4,6 +4,7 @@
 
 use PHPStan\PhpDocParser\Ast\Type\IdentifierTypeNode;
 use PHPStan\PhpDocParser\Ast\Type\TypeNode;
+use PHPStan\Type\Enum\EnumCaseObjectType;
 use PHPStan\Type\Traits\NonGeneralizableTypeTrait;
 use PHPStan\Type\Traits\NonGenericTypeTrait;
 use PHPStan\Type\Traits\ObjectTypeTrait;
@@ -130,6 +131,11 @@ public function getEnumCases(): array
 		return [];
 	}
 
+	public function getEnumCaseObject(): ?EnumCaseObjectType
+	{
+		return null;
+	}
+
 	public function subtract(Type $type): Type
 	{
 		if ($type instanceof self) {

src/Type/StaticType.php

@@ -15,6 +15,7 @@
 use PHPStan\Reflection\Type\UnresolvedMethodPrototypeReflection;
 use PHPStan\Reflection\Type\UnresolvedPropertyPrototypeReflection;
 use PHPStan\TrinaryLogic;
+use PHPStan\Type\Enum\EnumCaseObjectType;
 use PHPStan\Type\Generic\GenericObjectType;
 use PHPStan\Type\Generic\TemplateTypeHelper;
 use PHPStan\Type\Traits\NonGeneralizableTypeTrait;
@@ -539,6 +540,11 @@ public function getEnumCases(): array
 		return $this->getStaticObjectType()->getEnumCases();
 	}
 
+	public function getEnumCaseObject(): ?EnumCaseObjectType
+	{
+		return $this->getStaticObjectType()->getEnumCaseObject();
+	}
+
 	public function isArray(): TrinaryLogic
 	{
 		return $this->getStaticObjectType()->isArray();

src/Type/StrictMixedType.php

@@ -13,6 +13,7 @@
 use PHPStan\Reflection\Type\UnresolvedPropertyPrototypeReflection;
 use PHPStan\ShouldNotHappenException;
 use PHPStan\TrinaryLogic;
+use PHPStan\Type\Enum\EnumCaseObjectType;
 use PHPStan\Type\Generic\TemplateMixedType;
 use PHPStan\Type\Generic\TemplateTypeMap;
 use PHPStan\Type\Generic\TemplateTypeVariance;
@@ -445,6 +446,11 @@ public function getEnumCases(): array
 		return [];
 	}
 
+	public function getEnumCaseObject(): ?EnumCaseObjectType
+	{
+		return null;
+	}
+
 	public function traverse(callable $cb): Type
 	{
 		return $this;

src/Type/Traits/LateResolvableTypeTrait.php

@@ -13,6 +13,7 @@
 use PHPStan\Type\AcceptsResult;
 use PHPStan\Type\BooleanType;
 use PHPStan\Type\CompoundType;
+use PHPStan\Type\Enum\EnumCaseObjectType;
 use PHPStan\Type\Generic\TemplateTypeMap;
 use PHPStan\Type\IsSuperTypeOfResult;
 use PHPStan\Type\LateResolvableType;
@@ -358,6 +359,11 @@ public function getEnumCases(): array
 		return $this->resolve()->getEnumCases();
 	}
 
+	public function getEnumCaseObject(): ?EnumCaseObjectType
+	{
+		return $this->resolve()->getEnumCaseObject();
+	}
+
 	public function getCallableParametersAcceptors(ClassMemberAccessAnswerer $scope): array
 	{
 		return $this->resolve()->getCallableParametersAcceptors($scope);

src/Type/Traits/NonObjectTypeTrait.php

@@ -10,6 +10,7 @@
 use PHPStan\Reflection\Type\UnresolvedPropertyPrototypeReflection;
 use PHPStan\ShouldNotHappenException;
 use PHPStan\TrinaryLogic;
+use PHPStan\Type\Enum\EnumCaseObjectType;
 use PHPStan\Type\ErrorType;
 use PHPStan\Type\Type;
 
@@ -126,6 +127,11 @@ public function getEnumCases(): array
 		return [];
 	}
 
+	public function getEnumCaseObject(): ?EnumCaseObjectType
+	{
+		return null;
+	}
+
 	public function getTemplateType(string $ancestorClassName, string $templateTypeName): Type
 	{
 		return new ErrorType();

src/Type/Type.php

@@ -186,6 +186,8 @@ public function spliceArray(Type $offsetType, Type $lengthType, Type $replacemen
 	 */
 	public function getEnumCases(): array;
 
+	public function getEnumCaseObject(): ?EnumCaseObjectType;
+
 	/**
 	 * Returns a list of finite values.
 	 *