Improve EnumSanityRule

Makefile

@@ -20,6 +20,7 @@ lint:
 		--exclude tests/PHPStan/Rules/Names/data \
 		--exclude tests/PHPStan/Rules/Operators/data/invalid-inc-dec.php \
 		--exclude tests/PHPStan/Rules/Arrays/data/offset-access-without-dim-for-reading.php \
+		--exclude tests/PHPStan/Rules/Classes/data/bug-13768.php \
 		--exclude tests/PHPStan/Rules/Classes/data/duplicate-declarations.php \
 		--exclude tests/PHPStan/Rules/Classes/data/duplicate-enum-cases.php \
 		--exclude tests/PHPStan/Rules/Classes/data/enum-sanity.php \

src/Rules/Classes/EnumSanityRule.php

@@ -8,6 +8,7 @@
 use PHPStan\Node\InClassNode;
 use PHPStan\Rules\Rule;
 use PHPStan\Rules\RuleErrorBuilder;
+use PHPStan\ShouldNotHappenException;
 use PHPStan\Type\IntegerType;
 use PHPStan\Type\StringType;
 use PHPStan\Type\VerbosityLevel;
@@ -16,6 +17,8 @@
 use function count;
 use function implode;
 use function in_array;
+use function is_int;
+use function is_string;
 use function sprintf;
 
 /**
@@ -145,27 +148,16 @@ public function processNode(Node $node, Scope $scope): array
 			}
 			$caseName = $stmt->name->name;
 
-			if ($stmt->expr instanceof Node\Scalar\Int_ || $stmt->expr instanceof Node\Scalar\String_) {
-				if ($enumNode->scalarType === null) {
-					$errors[] = RuleErrorBuilder::message(sprintf(
-						'Enum %s is not backed, but case %s has value %s.',
-						$classReflection->getDisplayName(),
-						$caseName,
-						$stmt->expr->value,
-					))
-						->identifier('enum.caseWithValue')
-						->line($stmt->getStartLine())
-						->nonIgnorable()
-						->build();
-				} else {
-					$caseValue = $stmt->expr->value;
-
-					if (!isset($enumCases[$caseValue])) {
-						$enumCases[$caseValue] = [];
-					}
-
-					$enumCases[$caseValue][] = $caseName;
-				}
+			if ($enumNode->scalarType === null && $stmt->expr !== null) {
+				$errors[] = RuleErrorBuilder::message(sprintf(
+					'Enum %s is not backed, but case %s has value.',
+					$classReflection->getDisplayName(),
+					$caseName,
+				))
+					->identifier('enum.caseWithValue')
+					->line($stmt->getStartLine())
+					->nonIgnorable()
+					->build();
 			}
 
 			if ($enumNode->scalarType === null) {
@@ -189,6 +181,20 @@ public function processNode(Node $node, Scope $scope): array
 			$exprType = $scope->getType($stmt->expr);
 			$scalarType = $enumNode->scalarType->toLowerString() === 'int' ? new IntegerType() : new StringType();
 			if ($scalarType->isSuperTypeOf($exprType)->yes()) {
+				$constantValues = $exprType->getConstantScalarValues();
+				if (count($constantValues) === 1) {
+					$caseValue = $constantValues[0];
+					if (!is_string($caseValue) && !is_int($caseValue)) {
+						throw new ShouldNotHappenException();
+					}
+
+					if (!isset($enumCases[$caseValue])) {
+						$enumCases[$caseValue] = [];
+					}
+
+					$enumCases[$caseValue][] = $caseName;
+				}
+
 				continue;
 			}
 

tests/PHPStan/Rules/Classes/EnumSanityRuleTest.php

@@ -95,7 +95,7 @@ public function testRule(): void
 				110,
 			],
 			[
-				'Enum EnumSanity\EnumWithValueButNotBacked is not backed, but case FOO has value 1.',
+				'Enum EnumSanity\EnumWithValueButNotBacked is not backed, but case FOO has value.',
 				114,
 			],
 			[
@@ -119,24 +119,28 @@ public function testBug9402(): void
 	}
 
 	#[RequiresPhp('>= 8.1')]
-	public function testBug11592(): void
+	public function testBug13768(): void
 	{
-		$this->analyse([__DIR__ . '/data/bug-11592.php'], [
+		$this->analyse([__DIR__ . '/data/bug-13768.php'], [
 			[
-				'Enum Bug11592\Test2 cannot redeclare native method cases().',
-				22,
+				'Enum Bug13768\Order is not backed, but case A has value.',
+				7,
 			],
 			[
-				'Enum Bug11592\BackedTest2 cannot redeclare native method cases().',
-				37,
+				'Enum Bug13768\Order is not backed, but case B has value.',
+				8,
 			],
 			[
-				'Enum Bug11592\BackedTest2 cannot redeclare native method from().',
-				39,
+				'Enum Bug13768\Order is not backed, but case C has value.',
+				9,
+			],
+			[
+				'Enum Bug13768\Order is not backed, but case D has value.',
+				10,
 			],
 			[
-				'Enum Bug11592\BackedTest2 cannot redeclare native method tryFrom().',
-				41,
+				'Enum Bug13768\Backed has duplicate value 1 for cases One, Two.',
+				18,
 			],
 		]);
 	}

tests/PHPStan/Rules/Classes/data/bug-13768.php

@@ -0,0 +1,21 @@
+<?php // lint >= 8.1
+
+namespace Bug13768;
+
+enum Order {
+	case U;
+	case A = 1.5;
+	case B = 2.5;
+	case C = 3;
+	case D = '3';
+}
+
+class Foo
+{
+	public const A = 1;
+}
+
+enum Backed: int {
+	case One = Foo::A;
+	case Two = Foo::A;
+}