ArrayType::setOffsetValueType() - generalize item type if it goes over a threshold

Author: ondrejmirtes

src/Type/ArrayType.php

@@ -285,10 +285,15 @@ public function setOffsetValueType(?Type $offsetType, Type $valueType, bool $uni
 			$keyType = $keyType->generalize(GeneralizePrecision::moreSpecific());
 		}
 
-		$array = new self(
-			$keyType,
-			$unionValues ? TypeCombinator::union($this->itemType, $valueType) : $valueType,
-		);
+		$itemType = $valueType;
+		if ($unionValues) {
+			$itemType = TypeCombinator::union($this->itemType, $valueType);
+			if (count(TypeUtils::getConstantScalars($itemType)) > ConstantArrayTypeBuilder::ARRAY_COUNT_LIMIT) {
+				$itemType = $itemType->generalize(GeneralizePrecision::moreSpecific());
+			}
+		}
+
+		$array = new self($keyType, $itemType,);
 		if ($offsetType instanceof ConstantIntegerType || $offsetType instanceof ConstantStringType) {
 			return TypeCombinator::intersect($array, new HasOffsetValueType($offsetType, $valueType), new NonEmptyArrayType());
 		}