Preserve template bound for enum-case, integer-range and constant-bool subtypes in TemplateTypeFactory::create() (#5905)

Co-authored-by: staabm <120441+staabm@users.noreply.github.com>
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

Author: 3 people

src/Type/Generic/TemplateTypeFactory.php

@@ -10,6 +10,7 @@
 use PHPStan\Type\Constant\ConstantIntegerType;
 use PHPStan\Type\Constant\ConstantStringType;
 use PHPStan\Type\FloatType;
+use PHPStan\Type\IntegerRangeType;
 use PHPStan\Type\IntegerType;
 use PHPStan\Type\IntersectionType;
 use PHPStan\Type\IterableType;
@@ -39,14 +40,17 @@ public static function create(TemplateTypeScope $scope, string $name, ?Type $bou
 		}
 
 		$boundClass = get_class($bound);
-		if ($bound instanceof ObjectType && ($boundClass === ObjectType::class || $bound instanceof TemplateType)) {
-			return new TemplateObjectType($scope, $strategy, $variance, $name, $bound, $default);
-		}
-
 		if ($bound instanceof GenericObjectType && ($boundClass === GenericObjectType::class || $bound instanceof TemplateType)) {
 			return new TemplateGenericObjectType($scope, $strategy, $variance, $name, $bound, $default);
 		}
 
+		// Catches plain ObjectType and any other object subtype without a dedicated
+		// Template* class (e.g. enum-case object types), preserving the precise bound
+		// instead of widening it to TemplateMixedType.
+		if ($bound instanceof ObjectType) {
+			return new TemplateObjectType($scope, $strategy, $variance, $name, $bound, $default);
+		}
+
 		if ($bound instanceof ObjectWithoutClassType && ($boundClass === ObjectWithoutClassType::class || $bound instanceof TemplateType)) {
 			return new TemplateObjectWithoutClassType($scope, $strategy, $variance, $name, $bound, $default);
 		}
@@ -71,7 +75,7 @@ public static function create(TemplateTypeScope $scope, string $name, ?Type $bou
 			return new TemplateConstantStringType($scope, $strategy, $variance, $name, $bound, $default);
 		}
 
-		if ($bound instanceof IntegerType && ($boundClass === IntegerType::class || $bound instanceof TemplateType)) {
+		if ($bound instanceof IntegerType && ($boundClass === IntegerType::class || $bound instanceof IntegerRangeType || $bound instanceof TemplateType)) {
 			return new TemplateIntegerType($scope, $strategy, $variance, $name, $bound, $default);
 		}
 
@@ -83,7 +87,7 @@ public static function create(TemplateTypeScope $scope, string $name, ?Type $bou
 			return new TemplateFloatType($scope, $strategy, $variance, $name, $bound, $default);
 		}
 
-		if ($bound instanceof BooleanType && ($boundClass === BooleanType::class || $bound instanceof TemplateType)) {
+		if ($bound instanceof BooleanType && ($boundClass === BooleanType::class || $bound->isTrue()->yes() || $bound->isFalse()->yes() || $bound instanceof TemplateType)) {
 			return new TemplateBooleanType($scope, $strategy, $variance, $name, $bound, $default);
 		}
 

tests/PHPStan/Analyser/nsrt/bug-10083.php

@@ -0,0 +1,49 @@
+<?php // lint >= 8.1
+
+namespace Bug10083;
+
+use function PHPStan\Testing\assertType;
+
+enum Foo
+{
+
+	case Abc;
+	case Bcd;
+
+}
+
+/**
+ * @template TFoo of Foo::*
+ * @param TFoo $foo
+ */
+function checkFoo($foo): void
+{
+}
+
+/**
+ * @template TFoo of Foo::*
+ * @param TFoo $foo
+ */
+function narrowEnum($foo): void
+{
+	if (Foo::Abc === $foo) {
+		assertType('TFoo of Bug10083\Foo::Abc (function Bug10083\narrowEnum(), argument)', $foo);
+	} else {
+		assertType('TFoo of Bug10083\Foo::Bcd (function Bug10083\narrowEnum(), argument)', $foo);
+	}
+
+	$filter = Foo::Abc === $foo ? 'Abc' : 'Bcd';
+	assertType('TFoo of Bug10083\Foo::Abc (function Bug10083\narrowEnum(), argument)|TFoo of Bug10083\Foo::Bcd (function Bug10083\narrowEnum(), argument)', $foo);
+	checkFoo($foo);
+}
+
+/**
+ * @template TInt of int
+ * @param TInt $int
+ */
+function narrowIntRange($int): void
+{
+	if ($int >= 0 && $int <= 5) {
+		assertType('TInt of int<0, 5> (function Bug10083\narrowIntRange(), argument)', $int);
+	}
+}

tests/PHPStan/Type/TypeCombinatorTest.php

@@ -45,6 +45,7 @@
 use PHPStan\Type\Generic\GenericObjectType;
 use PHPStan\Type\Generic\GenericStaticType;
 use PHPStan\Type\Generic\TemplateBenevolentUnionType;
+use PHPStan\Type\Generic\TemplateBooleanType;
 use PHPStan\Type\Generic\TemplateIntersectionType;
 use PHPStan\Type\Generic\TemplateMixedType;
 use PHPStan\Type\Generic\TemplateObjectType;
@@ -6354,8 +6355,8 @@ public static function dataRemove(): array
 					TemplateTypeVariance::createInvariant(),
 				),
 				new ConstantBooleanType(false),
-				TemplateMixedType::class, // should be TemplateConstantBooleanType
-				'T (class Foo, parameter)', // should be T of true
+				TemplateBooleanType::class,
+				'T of true (class Foo, parameter)',
 			],
 			[
 				new ObjectShapeType(['foo' => new IntegerType()], []),