Support value-of<BackedEnum>

src/PhpDoc/TypeNodeResolver.php

@@ -525,6 +525,26 @@ private function resolveGenericTypeNode(GenericTypeNode $typeNode, NameScope $na
 			return new ErrorType();
 		} elseif ($mainTypeName === 'value-of') {
 			if (count($genericTypes) === 1) { // value-of<ValueType>
+				if ($genericTypes[0] instanceof TypeWithClassName) {
+					if ($this->getReflectionProvider()->hasClass($genericTypes[0]->getClassName())) {
+						$classReflection = $this->getReflectionProvider()->getClass($genericTypes[0]->getClassName());
+
+						if ($classReflection->isBackedEnum()) {
+							$cases = [];
+							foreach ($classReflection->getEnumCases() as $enumCaseReflection) {
+								$backingType = $enumCaseReflection->getBackingValueType();
+								if ($backingType === null) {
+									continue;
+								}
+
+								$cases[] = $backingType;
+							}
+
+							return TypeCombinator::union(...$cases);
+						}
+					}
+				}
+
 				return $genericTypes[0]->getIterableValueType();
 			}
 

tests/PHPStan/Analyser/NodeScopeResolverTest.php

@@ -806,6 +806,10 @@ public function dataFileAsserts(): iterable
 			yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-6251.php');
 		}
 
+		if (PHP_VERSION_ID >= 80100) {
+			yield from $this->gatherAssertTypes(__DIR__ . '/data/value-of-enum.php');
+		}
+
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-6584.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-6439.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-6748.php');

tests/PHPStan/Analyser/data/value-of-enum.php

@@ -0,0 +1,36 @@
+<?php // lint >= 8.1
+
+declare(strict_types=1);
+
+namespace ValueOfEnum;
+
+use function PHPStan\Testing\assertType;
+
+enum Country: string
+{
+	case NL = 'The Netherlands';
+	case US = 'United States';
+}
+
+class Foo {
+	/**
+	 * @return value-of<Country>
+	 */
+	function us()
+	{
+		return Country::US;
+	}
+
+	/**
+	 * @param value-of<Country> $countryName
+	 */
+	function hello($countryName)
+	{
+		assertType("'The Netherlands'|'United States'", $countryName);
+	}
+
+	function doFoo() {
+		assertType("'The Netherlands'|'United States'", $this->us());
+	}
+}
+

tests/PHPStan/Rules/Methods/CallMethodsRuleTest.php

@@ -2287,6 +2287,22 @@ public function testEnums(): void
 				'Call to an undefined method CallMethodInEnum\Bar::doNonexistent().',
 				22,
 			],
+			[
+				'Parameter #1 $countryName of method CallMethodInEnum\FooCall::hello() expects \'The Netherlands\'|\'United States\', CallMethodInEnum\CountryNo::NL given.',
+				63,
+			],
+			[
+				'Parameter #1 $countryMap of method CallMethodInEnum\FooCall::helloArray() expects array<\'The Netherlands\'|\'United States\', bool>, array{abc: true} given.',
+				66,
+			],
+			[
+				'Parameter #1 $countryMap of method CallMethodInEnum\FooCall::helloArray() expects array<\'The Netherlands\'|\'United States\', bool>, array{abc: 123} given.',
+				67,
+			],
+			[
+				'Parameter #1 $countryMap of method CallMethodInEnum\FooCall::helloArray() expects array<\'The Netherlands\'|\'United States\', bool>, array{true} given.',
+				70,
+			],
 		]);
 	}
 

tests/PHPStan/Rules/Methods/data/call-method-in-enum.php

@@ -30,3 +30,43 @@ enum Bar
 	use FooTrait;
 
 }
+
+enum Country: string
+{
+	case NL = 'The Netherlands';
+	case US = 'United States';
+}
+
+enum CountryNo: int
+{
+	case NL = 1;
+	case US = 2;
+}
+
+enum FooCall {
+	/**
+	 * @param value-of<Country> $countryName
+	 */
+	function hello(string $countryName): void
+	{
+		// ...
+	}
+
+	/**
+	 * @param array<value-of<Country>, bool> $countryMap
+	 */
+	function helloArray(array $countryMap): void {
+		// ...
+	}
+
+	function doFooArray() {
+		$this->hello(CountryNo::NL);
+
+		// 'abc' does not match value-of<Country>
+		$this->helloArray(['abc' => true]);
+		$this->helloArray(['abc' => 123]);
+
+		// wrong key type
+		$this->helloArray([true]);
+	}
+}

tests/PHPStan/Rules/PhpDoc/IncompatiblePhpDocTypeRuleTest.php

@@ -204,4 +204,24 @@ public function testEnums(): void
 		]);
 	}
 
+	public function testValueOfEnum(): void
+	{
+		if (PHP_VERSION_ID < 80100) {
+			$this->markTestSkipped('This test needs PHP 8.1');
+		}
+
+		require __DIR__ . '/data/value-of-enum.php';
+
+		$this->analyse([__DIR__ . '/data/value-of-enum.php'], [
+			[
+				'PHPDoc tag @param for parameter $shouldError with type string is incompatible with native type int.',
+				31,
+			],
+			[
+				'PHPDoc tag @param for parameter $shouldError with type int is incompatible with native type string.',
+				38,
+			],
+		]);
+	}
+
 }

tests/PHPStan/Rules/PhpDoc/data/value-of-enum.php

@@ -0,0 +1,47 @@
+<?php // lint >= 8.1
+
+declare(strict_types=1);
+
+namespace ValueOfEnum;
+
+enum Country: string
+{
+	case NL = 'The Netherlands';
+	case US = 'United States';
+}
+
+enum CountryNo: int
+{
+	case NL = 1;
+	case US = 2;
+}
+
+class Foo {
+	/**
+	 * @param value-of<Country> $countryName
+	 */
+	function hello(string $countryName): void
+	{
+		// ...
+	}
+
+	/**
+	 * @param value-of<Country> $shouldError
+	 */
+	function helloError(int $shouldError): void
+	{
+		// ...
+	}
+	/**
+	 * @param value-of<CountryNo> $shouldError
+	 */
+	function helloError2(string $shouldError): void
+	{
+		// ...
+	}
+
+	function doFoo() {
+		$this->hello(Country::NL);
+	}
+}
+