Deduplicate inferred template type generalization logic

Author: ondrejmirtes

src/Analyser/MutatingScope.php

@@ -5063,16 +5063,7 @@ private function exactInstantiation(New_ $node, string $className): ?Type
 						return $type->getBound();
 					}
 
-					if (!$type->getVariance()->covariant()) {
-						$isArrayKey = $type->getBound()->describe(VerbosityLevel::precise()) === '(int|string)';
-						if ($newType->isScalar()->yes() && $isArrayKey) {
-							$newType = $newType->generalize(GeneralizePrecision::templateArgument());
-						} elseif ($newType->isConstantValue()->yes() && (!$type->getBound()->isScalar()->yes() || $isArrayKey)) {
-							$newType = $newType->generalize(GeneralizePrecision::templateArgument());
-						}
-					}
-
-					return $newType;
+					return TemplateTypeHelper::generalizeInferredTemplateType($type, $newType);
 				}
 
 				return $traverse($type);

src/Reflection/ResolvedFunctionVariant.php

@@ -6,7 +6,6 @@
 use PHPStan\Reflection\Php\DummyParameterWithPhpDocs;
 use PHPStan\Type\ConditionalTypeForParameter;
 use PHPStan\Type\ErrorType;
-use PHPStan\Type\GeneralizePrecision;
 use PHPStan\Type\Generic\GenericObjectType;
 use PHPStan\Type\Generic\TemplateType;
 use PHPStan\Type\Generic\TemplateTypeHelper;
@@ -17,7 +16,6 @@
 use PHPStan\Type\Type;
 use PHPStan\Type\TypeTraverser;
 use PHPStan\Type\TypeUtils;
-use PHPStan\Type\VerbosityLevel;
 use function array_key_exists;
 use function array_map;
 
@@ -184,15 +182,7 @@ private function resolveResolvableTemplateTypes(Type $type, TemplateTypeVariance
 					return $traverse($type);
 				}
 
-				if (!$type->getVariance()->covariant()) {
-					$isArrayKey = $type->getBound()->describe(VerbosityLevel::precise()) === '(int|string)';
-					if ($newType->isScalar()->yes() && $isArrayKey) {
-						$newType = $newType->generalize(GeneralizePrecision::templateArgument());
-					} elseif ($newType->isConstantValue()->yes() && (!$type->getBound()->isScalar()->yes() || $isArrayKey)) {
-						$newType = $newType->generalize(GeneralizePrecision::templateArgument());
-					}
-				}
-
+				$newType = TemplateTypeHelper::generalizeInferredTemplateType($type, $newType);
 				$variance = TemplateTypeVariance::createInvariant();
 				foreach ($references as $reference) {
 					// this uses identity to distinguish between different occurrences of the same template type

src/Type/Generic/TemplateTypeHelper.php

@@ -3,9 +3,11 @@
 namespace PHPStan\Type\Generic;
 
 use PHPStan\Type\ErrorType;
+use PHPStan\Type\GeneralizePrecision;
 use PHPStan\Type\NonAcceptingNeverType;
 use PHPStan\Type\Type;
 use PHPStan\Type\TypeTraverser;
+use PHPStan\Type\VerbosityLevel;
 
 class TemplateTypeHelper
 {
@@ -93,4 +95,18 @@ public static function toArgument(Type $type): Type
 		});
 	}
 
+	public static function generalizeInferredTemplateType(TemplateType $templateType, Type $type): Type
+	{
+		if (!$templateType->getVariance()->covariant()) {
+			$isArrayKey = $templateType->getBound()->describe(VerbosityLevel::precise()) === '(int|string)';
+			if ($type->isScalar()->yes() && $isArrayKey) {
+				$type = $type->generalize(GeneralizePrecision::templateArgument());
+			} elseif ($type->isConstantValue()->yes() && (!$templateType->getBound()->isScalar()->yes() || $isArrayKey)) {
+				$type = $type->generalize(GeneralizePrecision::templateArgument());
+			}
+		}
+
+		return $type;
+	}
+
 }