Fix infinite recursion when asking isSuperTypeOf() between template union types

Author: ondrejmirtes

src/Type/Generic/TemplateTypeTrait.php

@@ -118,7 +118,11 @@ public function isSuperTypeOf(Type $type): TrinaryLogic
 	public function isSubTypeOf(Type $type): TrinaryLogic
 	{
 		$boundClass = get_class($this->getBound());
-		if (!$type instanceof $boundClass && ($type instanceof UnionType || $type instanceof IntersectionType)) {
+		if (
+			!$type instanceof $boundClass
+			&& !$type instanceof TemplateType
+			&& ($type instanceof UnionType || $type instanceof IntersectionType)
+		) {
 			return $type->isSuperTypeOf($this);
 		}
 

tests/PHPStan/Type/TemplateTypeTest.php

@@ -206,6 +206,48 @@ public function dataIsSuperTypeOf(): array
 				TrinaryLogic::createMaybe(),
 				TrinaryLogic::createMaybe(),
 			],
+			[
+				$templateType('T', new MixedType(true)),
+				$templateType('U', new UnionType([new IntegerType(), new StringType()])),
+				TrinaryLogic::createMaybe(),
+				TrinaryLogic::createMaybe(),
+			],
+			[
+				$templateType('T', new MixedType(true)),
+				$templateType('U', new BenevolentUnionType([new IntegerType(), new StringType()])),
+				TrinaryLogic::createMaybe(),
+				TrinaryLogic::createMaybe(),
+			],
+			[
+				$templateType('T', new ObjectType(\stdClass::class)),
+				$templateType('U', new BenevolentUnionType([new IntegerType(), new StringType()])),
+				TrinaryLogic::createNo(),
+				TrinaryLogic::createNo(),
+			],
+			[
+				$templateType('T', new BenevolentUnionType([new IntegerType(), new StringType()])),
+				$templateType('T', new BenevolentUnionType([new IntegerType(), new StringType()])),
+				TrinaryLogic::createYes(),
+				TrinaryLogic::createYes(),
+			],
+			[
+				$templateType('T', new UnionType([new IntegerType(), new StringType()])),
+				$templateType('T', new UnionType([new IntegerType(), new StringType()])),
+				TrinaryLogic::createYes(),
+				TrinaryLogic::createYes(),
+			],
+			[
+				$templateType('T', new UnionType([new IntegerType(), new StringType()])),
+				$templateType('T', new BenevolentUnionType([new IntegerType(), new StringType()])),
+				TrinaryLogic::createMaybe(),
+				TrinaryLogic::createMaybe(),
+			],
+			[
+				$templateType('T', new UnionType([new IntegerType(), new StringType()])),
+				$templateType('T', new IntegerType()),
+				TrinaryLogic::createMaybe(),
+				TrinaryLogic::createMaybe(),
+			],
 		];
 	}