Support @readonly PHPDoc on the class as alternative to @immutable

src/Reflection/ClassReflection.php

@@ -1238,7 +1238,7 @@ public function isImmutable(): bool
  {
  if ($this->isImmutable === null) {
  $resolvedPhpDoc = $this->getResolvedPhpDoc();
- $this->isImmutable = $resolvedPhpDoc !== null && $resolvedPhpDoc->isImmutable();
+ $this->isImmutable = $resolvedPhpDoc !== null && ($resolvedPhpDoc->isImmutable() || $resolvedPhpDoc->isReadOnly());
 
  $parentClass = $this->getParentClass();
  if ($parentClass !== null && !$this->isImmutable) {

tests/PHPStan/Rules/Properties/ReadOnlyByPhpDocPropertyAssignRuleTest.php

@@ -160,4 +160,22 @@ public function testFeature7648(): void
  $this->analyse([__DIR__ . '/data/feature-7648.php'], []);
  }
 
+ public function testFeature11775(): void
+ {
+ if (PHP_VERSION_ID < 70400) {
+ $this->markTestSkipped('Test requires PHP 7.4.');
+ }
+
+ $this->analyse([__DIR__ . '/data/feature-11775.php'], [
+ [
+ '@readonly property Feature11775\FooImmutable::$i is assigned outside of the constructor.',
+ 22,
+ ],
+ [
+ '@readonly property Feature11775\FooReadonly::$i is assigned outside of the constructor.',
+ 43,
+ ],
+ ]);
+ }
+
 }

tests/PHPStan/Rules/Properties/data/feature-11775.php

@@ -0,0 +1,45 @@
+<?php declare(strict_types = 1); // lint >= 7.4
+
+namespace Feature11775;
+
+/** @immutable */
+class FooImmutable
+{
+ private int $i;
+
+ public function __construct(int $i)
+ {
+ $this->i = $i;
+ }
+
+ public function getId(): int
+ {
+ return $this->i;
+ }
+
+ public function setId(): void
+ {
+ $this->i = 5;
+ }
+}
+
+/** @readonly */
+class FooReadonly
+{
+ private int $i;
+
+ public function __construct(int $i)
+ {
+ $this->i = $i;
+ }
+
+ public function getId(): int
+ {
+ return $this->i;
+ }
+
+ public function setId(): void
+ {
+ $this->i = 5;
+ }
+}