Extract AllowedArrayKeysTypes::narrowOffsetKeyType() to ease re-use

Author: staabm

src/Analyser/TypeSpecifier.php

@@ -28,6 +28,7 @@
 use PHPStan\Reflection\ParametersAcceptorWithPhpDocs;
 use PHPStan\Reflection\ReflectionProvider;
 use PHPStan\Reflection\ResolvedFunctionVariant;
+use PHPStan\Rules\Arrays\AllowedArrayKeysTypes;
 use PHPStan\ShouldNotHappenException;
 use PHPStan\TrinaryLogic;
 use PHPStan\Type\Accessory\AccessoryArrayListType;
@@ -820,47 +821,8 @@ public function specifyTypesInCondition(
 						);
 					} else {
 						$varType = $scope->getType($var->var);
-						if ($varType->isArray()->yes() && !$varType->isIterableAtLeastOnce()->no()) {
-							$varIterableKeyType = $varType->getIterableKeyType();
-
-							if ($varIterableKeyType->isConstantScalarValue()->yes()) {
-								$narrowedKey = TypeCombinator::union(
-									$varIterableKeyType,
-									TypeCombinator::remove($varIterableKeyType->toString(), new ConstantStringType('')),
-								);
-
-								if (!$varType->hasOffsetValueType(new ConstantIntegerType(0))->no()) {
-									$narrowedKey = TypeCombinator::union(
-										$narrowedKey,
-										new ConstantBooleanType(false),
-									);
-								}
-
-								if (!$varType->hasOffsetValueType(new ConstantIntegerType(1))->no()) {
-									$narrowedKey = TypeCombinator::union(
-										$narrowedKey,
-										new ConstantBooleanType(true),
-									);
-								}
-
-								if (!$varType->hasOffsetValueType(new ConstantStringType(''))->no()) {
-									$narrowedKey = TypeCombinator::addNull($narrowedKey);
-								}
-
-								if (!$varIterableKeyType->isNumericString()->no() || !$varIterableKeyType->isInteger()->no()) {
-									$narrowedKey = TypeCombinator::union($narrowedKey, new FloatType());
-								}
-							} else {
-								$narrowedKey = new MixedType(
-									false,
-									new UnionType([
-										new ArrayType(new MixedType(), new MixedType()),
-										new ObjectWithoutClassType(),
-										new ResourceType(),
-									]),
-								);
-							}
-
+						$narrowedKey = AllowedArrayKeysTypes::narrowOffsetKeyType($varType);
+						if ($narrowedKey !== null) {
 							$types = $types->unionWith(
 								$this->create(
 									$var->dim,

src/Rules/Arrays/AllowedArrayKeysTypes.php

@@ -2,12 +2,20 @@
 
 namespace PHPStan\Rules\Arrays;
 
+use PHPStan\Type\ArrayType;
 use PHPStan\Type\BooleanType;
+use PHPStan\Type\Constant\ConstantBooleanType;
+use PHPStan\Type\Constant\ConstantIntegerType;
+use PHPStan\Type\Constant\ConstantStringType;
 use PHPStan\Type\FloatType;
 use PHPStan\Type\IntegerType;
+use PHPStan\Type\MixedType;
 use PHPStan\Type\NullType;
+use PHPStan\Type\ObjectWithoutClassType;
+use PHPStan\Type\ResourceType;
 use PHPStan\Type\StringType;
 use PHPStan\Type\Type;
+use PHPStan\Type\TypeCombinator;
 use PHPStan\Type\UnionType;
 
 final class AllowedArrayKeysTypes
@@ -24,4 +32,51 @@ public static function getType(): Type
 		]);
 	}
 
+	public static function narrowOffsetKeyType(Type $varType): ?Type {
+		if (!$varType->isArray()->yes() || $varType->isIterableAtLeastOnce()->no()) {
+			return null;
+		}
+
+		$varIterableKeyType = $varType->getIterableKeyType();
+
+		if ($varIterableKeyType->isConstantScalarValue()->yes()) {
+			$narrowedKey = TypeCombinator::union(
+				$varIterableKeyType,
+				TypeCombinator::remove($varIterableKeyType->toString(), new ConstantStringType('')),
+			);
+
+			if (!$varType->hasOffsetValueType(new ConstantIntegerType(0))->no()) {
+				$narrowedKey = TypeCombinator::union(
+					$narrowedKey,
+					new ConstantBooleanType(false),
+				);
+			}
+
+			if (!$varType->hasOffsetValueType(new ConstantIntegerType(1))->no()) {
+				$narrowedKey = TypeCombinator::union(
+					$narrowedKey,
+					new ConstantBooleanType(true),
+				);
+			}
+
+			if (!$varType->hasOffsetValueType(new ConstantStringType(''))->no()) {
+				$narrowedKey = TypeCombinator::addNull($narrowedKey);
+			}
+
+			if (!$varIterableKeyType->isNumericString()->no() || !$varIterableKeyType->isInteger()->no()) {
+				$narrowedKey = TypeCombinator::union($narrowedKey, new FloatType());
+			}
+		} else {
+			$narrowedKey = new MixedType(
+				false,
+				new UnionType([
+					new ArrayType(new MixedType(), new MixedType()),
+					new ObjectWithoutClassType(),
+					new ResourceType(),
+				]),
+			);
+		}
+
+		return $narrowedKey;
+	}
 }