Make value-of<...> lazier

Author: ondrejmirtes

src/PhpDoc/TypeNodeResolver.php

@@ -696,22 +696,8 @@ static function (string $variance): TemplateTypeVariance {
 return new ErrorType();
 } elseif ($mainTypeName === 'value-of') {
 if (count($genericTypes) === 1) { // value-of<ValueType>
-$genericType = $genericTypes[0];
-if ($genericType->isEnum()->yes()) {
-$valueTypes = [];
-foreach ($genericType->getEnumCases() as $enumCase) {
-$valueType = $enumCase->getBackingValueType();
-if ($valueType === null) {
-continue;
-}
-
-$valueTypes[] = $valueType;
-}
-
-return TypeCombinator::union(...$valueTypes);
-}
+$type = new ValueOfType($genericTypes[0]);
 
-$type = new ValueOfType($genericType);
 return $type->isResolvable() ? $type->resolve() : $type;
 }
 

src/Type/ValueOfType.php

@@ -49,6 +49,20 @@ public function isResolvable(): bool
 
 protected function getResult(): Type
 {
+if ($this->type->isEnum()->yes()) {
+$valueTypes = [];
+foreach ($this->type->getEnumCases() as $enumCase) {
+$valueType = $enumCase->getBackingValueType();
+if ($valueType === null) {
+continue;
+}
+
+$valueTypes[] = $valueType;
+}
+
+return TypeCombinator::union(...$valueTypes);
+}
+
 return $this->type->getIterableValueType();
 }
 

tests/PHPStan/Analyser/NodeScopeResolverTest.php

@@ -334,6 +334,11 @@ public function dataFileAsserts(): iterable
 yield from $this->gatherAssertTypes(__DIR__ . '/data/array-sum.php');
 yield from $this->gatherAssertTypes(__DIR__ . '/data/array-plus.php');
 yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-4573.php');
+
+if (PHP_VERSION_ID >= 80100) {
+yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-9881.php');
+}
+
 yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-4577.php');
 yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-4579.php');
 yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-3321.php');

tests/PHPStan/Analyser/data/bug-9881.php

@@ -0,0 +1,27 @@
+<?php // lint >= 8.1
+
+namespace Bug9881;
+
+use BackedEnum;
+use function PHPStan\Testing\assertType;
+
+class HelloWorld
+{
+/**
+ * @template B of BackedEnum
+ * @param B[] $enums
+ * @return value-of<B>[]
+ */
+public static function arrayEnumToStrings(array $enums): array
+{
+return array_map(static fn (BackedEnum $code): string|int => $code->value, $enums);
+}
+}
+
+enum Test: string {
+case DA = 'da';
+}
+
+function (Test ...$da): void {
+assertType('array<\'da\'>', HelloWorld::arrayEnumToStrings($da));
+};