Compute precise return types for getConstants() with multiple constant filter values

Instead of making all array keys optional when the filter has multiple
constant scalar values, compute the result for each filter value
separately and return their union.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: phpstan-bot

src/Type/Php/ReflectionClassGetConstantsDynamicReturnTypeExtension.php

@@ -118,8 +118,19 @@ private function resolveGetConstants(array $classReflections, ?Type $filterType)
 		$filterIsUncertain = false;
 		if ($filterType !== null) {
 			$filterScalars = $filterType->getConstantScalarValues();
-			if (count($filterScalars) === 1 && is_int($filterScalars[0])) {
-				$filter = $filterScalars[0];
+			$intFilters = [];
+			foreach ($filterScalars as $scalar) {
+				if (!is_int($scalar)) {
+					$intFilters = null;
+					break;
+				}
+				$intFilters[] = $scalar;
+			}
+
+			if ($intFilters !== null && count($intFilters) === 1) {
+				$filter = $intFilters[0];
+			} elseif ($intFilters !== null && count($intFilters) > 1) {
+				return $this->resolveGetConstantsForMultipleFilters($classReflections, $intFilters);
 			} else {
 				$filterIsUncertain = true;
 			}
@@ -141,6 +152,30 @@ private function resolveGetConstants(array $classReflections, ?Type $filterType)
 		return TypeCombinator::union(...$types);
 	}
 
+	/**
+	 * @param list<ClassReflection> $classReflections
+	 * @param list<int> $filters
+	 */
+	private function resolveGetConstantsForMultipleFilters(array $classReflections, array $filters): ?Type
+	{
+		$types = [];
+		foreach ($filters as $filter) {
+			foreach ($classReflections as $classReflection) {
+				$builder = ConstantArrayTypeBuilder::createEmpty();
+				foreach ($this->getClassConstants($classReflection, $filter) as [$name, $valueType]) {
+					$builder->setOffsetValueType(new ConstantStringType($name), $valueType);
+				}
+				$types[] = $builder->getArray();
+			}
+		}
+
+		if (count($types) === 0) {
+			return null;
+		}
+
+		return TypeCombinator::union(...$types);
+	}
+
 	/**
 	 * @return list<array{string, Type}>
 	 */

tests/PHPStan/Analyser/nsrt/reflection-class-get-constants.php

@@ -194,3 +194,12 @@ function testGetConstantsWithDynamicFilter(ReflectionClass $ref, int $filter): v
 {
 	assertType("array{A?: 1, B?: 'hello', C?: 3.14, D?: true}", $ref->getConstants($filter));
 }
+
+/**
+ * @param ReflectionClass<Foo> $ref
+ * @param \ReflectionClassConstant::IS_PUBLIC|\ReflectionClassConstant::IS_PROTECTED $filter
+ */
+function testGetConstantsWithMultipleConstantFilters(ReflectionClass $ref, int $filter): void
+{
+	assertType("array{A: 1, B: 'hello'}|array{C: 3.14}", $ref->getConstants($filter));
+}