enforceReadOnlyPublicProperty: fix false positive on PHP <= 8.0

src/Rule/EnforceReadonlyPublicPropertyRule.php

@@ -5,6 +5,7 @@
 use PhpParser\Node;
 use PHPStan\Analyser\Scope;
 use PHPStan\Node\ClassPropertyNode;
+use PHPStan\Php\PhpVersion;
 use PHPStan\Rules\Rule;
 
 /**
@@ -13,6 +14,13 @@
 class EnforceReadonlyPublicPropertyRule implements Rule
 {
 
+    private PhpVersion $phpVersion;
+
+    public function __construct(PhpVersion $phpVersion)
+    {
+        $this->phpVersion = $phpVersion;
+    }
+
     public function getNodeType(): string
     {
         return ClassPropertyNode::class;
@@ -24,6 +32,10 @@ public function getNodeType(): string
      */
     public function processNode(Node $node, Scope $scope): array
     {
+        if (!$this->phpVersion->supportsReadOnlyProperties()) {
+            return [];
+        }
+
         if (!$node->isPublic() || $node->isReadOnly()) {
             return [];
         }

tests/Rule/EnforceReadonlyPublicPropertyRuleTest.php

@@ -2,28 +2,39 @@
 
 namespace ShipMonk\PHPStan\Rule;
 
+use PHPStan\Php\PhpVersion;
 use PHPStan\Rules\Rule;
 use ShipMonk\PHPStan\RuleTestCase;
-use const PHP_VERSION_ID;
 
 /**
  * @extends RuleTestCase<EnforceReadonlyPublicPropertyRule>
  */
 class EnforceReadonlyPublicPropertyRuleTest extends RuleTestCase
 {
 
+    private ?PhpVersion $phpVersion = null;
+
     protected function getRule(): Rule
     {
-        return new EnforceReadonlyPublicPropertyRule();
+        self::assertNotNull($this->phpVersion);
+        return new EnforceReadonlyPublicPropertyRule($this->phpVersion);
+    }
+
+    public function testPhp81(): void
+    {
+        $this->phpVersion = $this->createPhpVersion(80_100);
+        $this->analyseFile(__DIR__ . '/data/EnforceReadonlyPublicPropertyRule/code-81.php');
     }
 
-    public function test(): void
+    public function testPhp80(): void
     {
-        if (PHP_VERSION_ID < 80_100) {
-            self::markTestSkipped('Requires PHP 8.1');
-        }
+        $this->phpVersion = $this->createPhpVersion(80_000);
+        $this->analyseFile(__DIR__ . '/data/EnforceReadonlyPublicPropertyRule/code-80.php');
+    }
 
-        $this->analyseFile(__DIR__ . '/data/EnforceReadonlyPublicPropertyRule/code.php');
+    private function createPhpVersion(int $version): PhpVersion
+    {
+        return new PhpVersion($version); // @phpstan-ignore-line ignore bc promise
     }
 
 }

tests/Rule/data/EnforceReadonlyPublicPropertyRule/code-80.php

@@ -0,0 +1,29 @@
+<?php
+
+namespace EnforceReadonlyPublicPropertyRule80;
+
+trait MyTrait {
+
+    public ?string $public;
+
+    protected string $protected;
+
+    private string $private;
+
+}
+
+class MyClass {
+
+    use MyTrait;
+
+    public ?int $foo;
+
+    public int $bar;
+
+    protected int $baz;
+
+    private int $bag;
+
+}
+
+

tests/Rule/data/EnforceReadonlyPublicPropertyRule/code.php → tests/Rule/data/EnforceReadonlyPublicPropertyRule/code-81.php

@@ -1,6 +1,6 @@
 <?php
 
-namespace EnforceReadonlyPublicPropertyRule;
+namespace EnforceReadonlyPublicPropertyRule81;
 
 trait MyTrait {