resolve class constant types when patching return types

Author: xabbuh

DebugClassLoader.php

@@ -849,6 +849,30 @@ private function setReturnType(string $types, string $class, string $method, str
         $docTypes = [];
 
         foreach ($typesMap as $n => $t) {
+            if (str_contains($n, '::')) {
+                [$definingClass, $constantName] = explode('::', $n, 2);
+                $definingClass = match ($definingClass) {
+                    'self', 'static', 'parent' => $class,
+                    default => $definingClass,
+                };
+
+                if (!\defined($definingClass.'::'.$constantName)) {
+                    return;
+                }
+
+                $constant = new \ReflectionClassConstant($definingClass, $constantName);
+
+                if (\PHP_VERSION_ID >= 80300 && $constantType = $constant->getType()) {
+                    if ($constantType instanceof \ReflectionNamedType) {
+                        $n = $constantType->getName();
+                    } else {
+                        return;
+                    }
+                } else {
+                    $n = \gettype($constant->getValue());
+                }
+            }
+
             if ('null' === $n) {
                 $nullable = true;
                 continue;
@@ -872,7 +896,7 @@ private function setReturnType(string $types, string $class, string $method, str
                 continue;
             }
 
-            if (!isset($phpTypes[''])) {
+            if (!isset($phpTypes['']) && !\in_array($n, $phpTypes, true)) {
                 $phpTypes[] = $n;
             }
         }

Tests/DebugClassLoaderTest.php

@@ -401,6 +401,26 @@ class_exists('Test\\'.ReturnType::class, true);
             'Method "Symfony\Component\ErrorHandler\Tests\Fixtures\ReturnTypeParent::true()" might add "true" as a native return type declaration in the future. Do the same in child class "Test\Symfony\Component\ErrorHandler\Tests\ReturnType" now to avoid errors or add an explicit @return annotation to suppress this message.',
             'Method "Symfony\Component\ErrorHandler\Tests\Fixtures\ReturnTypeParent::never()" might add "never" as a native return type declaration in the future. Do the same in child class "Test\Symfony\Component\ErrorHandler\Tests\ReturnType" now to avoid errors or add an explicit @return annotation to suppress this message.',
             'Method "Symfony\Component\ErrorHandler\Tests\Fixtures\ReturnTypeParent::null()" might add "null" as a native return type declaration in the future. Do the same in child class "Test\Symfony\Component\ErrorHandler\Tests\ReturnType" now to avoid errors or add an explicit @return annotation to suppress this message.',
+            'Method "Symfony\Component\ErrorHandler\Tests\Fixtures\ReturnTypeParent::classConstant()" might add "string" as a native return type declaration in the future. Do the same in child class "Test\Symfony\Component\ErrorHandler\Tests\ReturnType" now to avoid errors or add an explicit @return annotation to suppress this message.',
+        ], $deprecations);
+    }
+
+    /**
+     * @requires PHP >= 8.3
+     */
+    public function testReturnTypePhp83()
+    {
+        $deprecations = [];
+        set_error_handler(function ($type, $msg) use (&$deprecations) { $deprecations[] = $msg; });
+        $e = error_reporting(E_USER_DEPRECATED);
+
+        class_exists('Test\\'.ReturnTypePhp83::class, true);
+
+        error_reporting($e);
+        restore_error_handler();
+
+        $this->assertSame([
+            'Method "Symfony\Component\ErrorHandler\Tests\Fixtures\ReturnTypeParentPhp83::classConstantWithType()" might add "string" as a native return type declaration in the future. Do the same in child class "Test\Symfony\Component\ErrorHandler\Tests\ReturnTypePhp83" now to avoid errors or add an explicit @return annotation to suppress this message.',
         ], $deprecations);
     }
 
@@ -542,6 +562,8 @@ public function ownAbstractBaseMethod() { }
             }');
         } elseif ('Test\\'.ReturnType::class === $class) {
             return $fixtureDir.\DIRECTORY_SEPARATOR.'ReturnType.php';
+        } elseif ('Test\\'.ReturnTypePhp83::class === $class) {
+            return $fixtureDir.\DIRECTORY_SEPARATOR.'ReturnTypePhp83.php';
         } elseif ('Test\\'.Fixtures\OutsideInterface::class === $class) {
             return $fixtureDir.\DIRECTORY_SEPARATOR.'OutsideInterface.php';
         } elseif ('Test\\'.OverrideOutsideFinalProperty::class === $class) {

Tests/Fixtures/ReturnType.php

@@ -51,4 +51,5 @@ public function true() { }
     public function never() { }
     public function null() { }
     public function outsideMethod() { }
+    public function classConstant() { }
 }

Tests/Fixtures/ReturnTypeParent.php

@@ -4,6 +4,8 @@
 
 abstract class ReturnTypeParent extends ReturnTypeGrandParent implements ReturnTypeParentInterface
 {
+    const FOO = 'foo';
+
     /**
      * @return void
      */
@@ -254,4 +256,11 @@ public function null()
     public function notExtended()
     {
     }
+
+    /**
+     * @return self::FOO
+     */
+    public function classConstant()
+    {
+    }
 }

Tests/Fixtures/ReturnTypeParentPhp83.php

@@ -0,0 +1,23 @@
+<?php
+
+namespace Symfony\Component\ErrorHandler\Tests\Fixtures;
+
+abstract class ReturnTypeParentPhp83
+{
+    const string FOO = 'foo';
+    const string|int BAR = 'bar';
+
+    /**
+     * @return self::FOO
+     */
+    public function classConstantWithType()
+    {
+    }
+
+    /**
+     * @return self::BAR
+     */
+    public function classConstantWithUnionType()
+    {
+    }
+}

Tests/Fixtures/ReturnTypePhp83.php

@@ -0,0 +1,11 @@
+<?php
+
+namespace Test\Symfony\Component\ErrorHandler\Tests;
+
+use Symfony\Component\ErrorHandler\Tests\Fixtures\ReturnTypeParentPhp83;
+
+class ReturnTypePhp83 extends ReturnTypeParentPhp83
+{
+    public function classConstantWithType() { }
+    public function classConstantWithUnionType() { }
+}