Generics - do not generalize array shape

Author: ondrejmirtes

src/Type/Constant/ConstantArrayType.php

@@ -793,23 +793,9 @@ public function getReferencedTemplateTypes(TemplateTypeVariance $positionVarianc
 
 	public function traverse(callable $cb): Type
 	{
-		$keyTypes = [];
 		$valueTypes = [];
 
 		$stillOriginal = true;
-		foreach ($this->keyTypes as $keyType) {
-			$transformedKeyType = $cb($keyType);
-			if ($transformedKeyType !== $keyType) {
-				$stillOriginal = false;
-			}
-
-			if (!$transformedKeyType instanceof ConstantIntegerType && !$transformedKeyType instanceof ConstantStringType) {
-				throw new \PHPStan\ShouldNotHappenException();
-			}
-
-			$keyTypes[] = $transformedKeyType;
-		}
-
 		foreach ($this->valueTypes as $valueType) {
 			$transformedValueType = $cb($valueType);
 			if ($transformedValueType !== $valueType) {
@@ -823,7 +809,7 @@ public function traverse(callable $cb): Type
 			return $this;
 		}
 
-		return new self($keyTypes, $valueTypes, $this->nextAutoIndex, $this->optionalKeys);
+		return new self($this->keyTypes, $valueTypes, $this->nextAutoIndex, $this->optionalKeys);
 	}
 
 	public function isKeysSupersetOf(self $otherArray): bool

src/Type/Generic/TemplateMixedType.php

@@ -7,7 +7,6 @@
 use PHPStan\Type\IntersectionType;
 use PHPStan\Type\MixedType;
 use PHPStan\Type\Type;
-use PHPStan\Type\TypeUtils;
 use PHPStan\Type\UnionType;
 use PHPStan\Type\VerbosityLevel;
 
@@ -134,7 +133,7 @@ public function inferTemplateTypes(Type $receivedType): TemplateTypeMap
 
 		if ($this->getBound()->isSuperTypeOf($receivedType)->yes()) {
 			return new TemplateTypeMap([
-				$this->name => TypeUtils::generalizeType($receivedType),
+				$this->name => TemplateTypeHelper::generalizeType($receivedType),
 			]);
 		}
 

src/Type/Generic/TemplateObjectType.php

@@ -9,7 +9,6 @@
 use PHPStan\Type\ObjectWithoutClassType;
 use PHPStan\Type\Traits\UndecidedComparisonCompoundTypeTrait;
 use PHPStan\Type\Type;
-use PHPStan\Type\TypeUtils;
 use PHPStan\Type\UnionType;
 use PHPStan\Type\VerbosityLevel;
 
@@ -150,7 +149,7 @@ public function inferTemplateTypes(Type $receivedType): TemplateTypeMap
 
 		if ($this->getBound()->isSuperTypeOf($receivedType)->yes()) {
 			return new TemplateTypeMap([
-				$this->name => TypeUtils::generalizeType($receivedType),
+				$this->name => TemplateTypeHelper::generalizeType($receivedType),
 			]);
 		}
 

src/Type/Generic/TemplateObjectWithoutClassType.php

@@ -8,7 +8,6 @@
 use PHPStan\Type\ObjectWithoutClassType;
 use PHPStan\Type\Traits\UndecidedComparisonCompoundTypeTrait;
 use PHPStan\Type\Type;
-use PHPStan\Type\TypeUtils;
 use PHPStan\Type\UnionType;
 use PHPStan\Type\VerbosityLevel;
 
@@ -177,7 +176,7 @@ public function inferTemplateTypes(Type $receivedType): TemplateTypeMap
 
 		if ($this->getBound()->isSuperTypeOf($receivedType)->yes()) {
 			return new TemplateTypeMap([
-				$this->name => TypeUtils::generalizeType($receivedType),
+				$this->name => TemplateTypeHelper::generalizeType($receivedType),
 			]);
 		}
 

src/Type/Generic/TemplateTypeHelper.php

@@ -2,6 +2,8 @@
 
 namespace PHPStan\Type\Generic;
 
+use PHPStan\Type\Constant\ConstantArrayType;
+use PHPStan\Type\ConstantType;
 use PHPStan\Type\ErrorType;
 use PHPStan\Type\StaticType;
 use PHPStan\Type\Type;
@@ -58,4 +60,15 @@ public static function toArgument(Type $type): Type
 		});
 	}
 
+	public static function generalizeType(Type $type): Type
+	{
+		return TypeTraverser::map($type, static function (Type $type, callable $traverse): Type {
+			if ($type instanceof ConstantType && !$type instanceof ConstantArrayType) {
+				return $type->generalize();
+			}
+
+			return $traverse($type);
+		});
+	}
+
 }

tests/PHPStan/Analyser/data/generics.php

@@ -97,7 +97,7 @@ function testD($int, $float, $intFloat)
 	assertType('DateTime|int', d($int, new \DateTime()));
 	assertType('DateTime|float|int', d($intFloat, new \DateTime()));
 	assertType('array()|DateTime', d([], new \DateTime()));
-	assertType('(array<string, string>&nonEmpty)|DateTime', d(['blabla' => 'barrrr'], new \DateTime()));
+	assertType('array(\'blabla\' => string)|DateTime', d(['blabla' => 'barrrr'], new \DateTime()));
 }
 
 /**
@@ -1394,3 +1394,8 @@ public function process($class): void {
 function (\Throwable $e): void {
 	assertType('mixed', $e->getCode());
 };
+
+function (): void {
+	$array = ['a' => 1, 'b' => 2];
+	assertType('array(\'a\' => int, \'b\' => int)', a($array));
+};