Short-circuit identical late-resolvable conditionals in subtype checks

Author: yt-catpaw

src/Type/Traits/LateResolvableTypeTrait.php

@@ -18,6 +18,7 @@
 use PHPStan\Type\LateResolvableType;
 use PHPStan\Type\NeverType;
 use PHPStan\Type\Type;
+use PHPStan\Type\UnionType;
 
 trait LateResolvableTypeTrait
 {
@@ -570,6 +571,18 @@ public function tryRemove(Type $typeToRemove): ?Type
 
 	public function isSubTypeOf(Type $otherType): IsSuperTypeOfResult
 	{
+		if ($this->equals($otherType)) {
+			return IsSuperTypeOfResult::createYes();
+		}
+
+		if ($otherType instanceof UnionType) {
+			foreach ($otherType->getTypes() as $innerType) {
+				if ($this->equals($innerType)) {
+					return IsSuperTypeOfResult::createYes();
+				}
+			}
+		}
+
 		$result = $this->resolve();
 
 		if ($result instanceof CompoundType) {

tests/PHPStan/Rules/Methods/MethodSignatureRuleTest.php

@@ -550,6 +550,13 @@ public function testBug10488(): void
 		$this->analyse([__DIR__ . '/data/bug-10488.php'], []);
 	}
 
+	public function testBug10942(): void
+	{
+		$this->reportMaybes = true;
+		$this->reportStatic = true;
+		$this->analyse([__DIR__ . '/data/bug-10942.php'], []);
+	}
+
 	#[RequiresPhp('>= 8.0')]
 	public function testBug12073(): void
 	{

tests/PHPStan/Rules/Methods/data/bug-10942.php

@@ -0,0 +1,27 @@
+<?php declare(strict_types = 1);
+
+namespace Bug10942;
+
+class A
+{
+
+	/**
+	 * @param string|($operator is 'in' ? int : never) $sqlRight
+	 */
+	protected function _renderConditionBinary(string $operator, string $sqlLeft, $sqlRight): string
+	{
+		return 'x';
+	}
+
+}
+
+class B extends A
+{
+
+	#[\Override]
+	protected function _renderConditionBinary(string $operator, string $sqlLeft, $sqlRight): string
+	{
+		return 'y';
+	}
+
+}