Cleanup ConstantArrayTypeBuilder (#4955)

Author: staabm

phpstan-baseline.neon

@@ -948,7 +948,7 @@ parameters:
 		-
 			rawMessage: 'Doing instanceof PHPStan\Type\Constant\ConstantStringType is error-prone and deprecated. Use Type::getConstantStrings() instead.'
 			identifier: phpstanApi.instanceofType
-			count: 2
+			count: 1
 			path: src/Type/Constant/ConstantArrayTypeBuilder.php
 
 		-

src/Type/Constant/ConstantArrayTypeBuilder.php

@@ -240,7 +240,7 @@ public function setOffsetValueType(?Type $offsetType, Type $valueType, bool $opt
 				return;
 			}
 
-			$scalarTypes = $offsetType->getConstantScalarTypes();
+			$scalarTypes = $offsetType->toArrayKey()->getConstantScalarTypes();
 			if (count($scalarTypes) === 0) {
 				$integerRanges = TypeUtils::getIntegerRanges($offsetType);
 				if (count($integerRanges) > 0) {
@@ -260,15 +260,11 @@ public function setOffsetValueType(?Type $offsetType, Type $valueType, bool $opt
 				$match = true;
 				$valueTypes = $this->valueTypes;
 				foreach ($scalarTypes as $scalarType) {
-					$scalarOffsetType = $scalarType->toArrayKey();
-					if (!$scalarOffsetType instanceof ConstantIntegerType && !$scalarOffsetType instanceof ConstantStringType) {
-						throw new ShouldNotHappenException();
-					}
 					$offsetMatch = false;
 
 					/** @var ConstantIntegerType|ConstantStringType $keyType */
 					foreach ($this->keyTypes as $i => $keyType) {
-						if ($keyType->getValue() !== $scalarOffsetType->getValue()) {
+						if ($keyType->getValue() !== $scalarType->getValue()) {
 							continue;
 						}