Fix phpstan/phpstan#10290: Accept subtypes in invariant generic template positions in accepts() context

- Modified GenericObjectType::isSuperTypeOfInternal() to accept subtypes for invariant
  template parameters when in the accepts context (used for error reporting)
- When the declared template variance is invariant and the type argument is a strict
  subtype, accepts() now returns Yes instead of No
- isSuperTypeOf() behavior remains unchanged (strict invariant equality)
- New regression test in tests/PHPStan/Rules/Functions/data/bug-10290.php
- Also fixes phpstan/phpstan#4590 (OkResponse<array{ok: string}> accepted for OkResponse<array<string, string>>)
- Updated existing tests to reflect the more lenient accepts behavior

Author: github-actions[bot]

src/Type/Generic/GenericObjectType.php

@@ -190,6 +190,8 @@ private function isSuperTypeOfInternal(Type $type, bool $acceptsContext): IsSupe
 			$ancestorVariance = $ancestor->variances[$i] ?? TemplateTypeVariance::createInvariant();
 			if (!$thisVariance->invariant()) {
 				$results[] = $thisVariance->isValidVariance($templateType, $this->types[$i], $ancestor->types[$i]);
+			} elseif ($acceptsContext && $templateType->getVariance()->invariant() && $this->types[$i]->isSuperTypeOf($ancestor->types[$i])->yes()) {
+				$results[] = IsSuperTypeOfResult::createYes();
 			} else {
 				$results[] = $templateType->isValidVariance($this->types[$i], $ancestor->types[$i]);
 			}

tests/PHPStan/Rules/Functions/ReturnTypeRuleTest.php

@@ -411,4 +411,17 @@ public function testBug12397(): void
 		$this->analyse([__DIR__ . '/data/bug-12397.php'], []);
 	}
 
+	#[RequiresPhp('>= 8.2')]
+	public function testBug10290(): void
+	{
+		$this->checkNullables = true;
+		$this->checkExplicitMixed = false;
+		$this->analyse([__DIR__ . '/data/bug-10290.php'], [
+			[
+				'Function Bug10290\g() should return Bug10290\Err<string>|Bug10290\Ok<true> but returns Bug10290\Ok<bool>.',
+				56,
+			],
+		]);
+	}
+
 }

tests/PHPStan/Rules/Functions/data/bug-10290.php

@@ -0,0 +1,60 @@
+<?php // lint >= 8.2
+
+declare(strict_types = 1);
+
+namespace Bug10290;
+
+/** @template T */
+abstract class Result
+{
+}
+
+/** @template T */
+final readonly class Ok extends Result
+{
+	/** @param T $data */
+	public function __construct(public mixed $data)
+	{
+	}
+}
+
+/** @template E */
+final readonly class Err extends Result
+{
+	/** @param E $data */
+	public function __construct(public mixed $data)
+	{
+	}
+}
+
+/**
+ * @return Ok<non-empty-string>|Err<array<mixed>>
+ */
+function f(string $json): Result
+{
+	$data = json_decode($json, true, 512, JSON_THROW_ON_ERROR);
+	assert(is_array($data));
+
+	if (isset($data['has_error']) && $data['has_error']) {
+		return new Err($data);
+	}
+
+	$email = filter_var($data['email'], FILTER_VALIDATE_EMAIL);
+	if ($email === false) {
+		return new Err($data);
+	}
+
+	return new Ok($email);
+}
+
+/**
+ * @return Ok<true>|Err<string>
+ */
+function g(): Result
+{
+	if (rand() === 1) {
+		return new Ok(true);
+	}
+
+	return new Err('error');
+}

tests/PHPStan/Rules/Methods/CallMethodsRuleTest.php

@@ -2220,13 +2220,7 @@ public function testGenericObjectLowerBound(): void
 		$this->checkThisOnly = false;
 		$this->checkNullables = true;
 		$this->checkUnionTypes = true;
-		$this->analyse([__DIR__ . '/../../Analyser/nsrt/generic-object-lower-bound.php'], [
-			[
-				'Parameter #1 $c of method GenericObjectLowerBound\Foo::doFoo() expects GenericObjectLowerBound\Collection<GenericObjectLowerBound\Cat|GenericObjectLowerBound\Dog>, GenericObjectLowerBound\Collection<GenericObjectLowerBound\Dog> given.',
-				48,
-				'Template type T on class GenericObjectLowerBound\Collection is not covariant. Learn more: <fg=cyan>https://phpstan.org/blog/whats-up-with-template-covariant</>',
-			],
-		]);
+		$this->analyse([__DIR__ . '/../../Analyser/nsrt/generic-object-lower-bound.php'], []);
 	}
 
 	public function testNonEmptyStringVerbosity(): void
@@ -2255,33 +2249,7 @@ public function testBug5372(): void
 		$this->checkThisOnly = false;
 		$this->checkNullables = true;
 		$this->checkUnionTypes = true;
-		$this->analyse([__DIR__ . '/data/bug-5372.php'], [
-			[
-				'Parameter #1 $list of method Bug5372\Foo::takesStrings() expects Bug5372\Collection<int, string>, Bug5372\Collection<int, non-falsy-string> given.',
-				64,
-				'Template type T on class Bug5372\Collection is not covariant. Learn more: <fg=cyan>https://phpstan.org/blog/whats-up-with-template-covariant</>',
-			],
-			[
-				'Parameter #1 $list of method Bug5372\Foo::takesStrings() expects Bug5372\Collection<int, string>, Bug5372\Collection<int, class-string> given.',
-				68,
-				'Template type T on class Bug5372\Collection is not covariant. Learn more: <fg=cyan>https://phpstan.org/blog/whats-up-with-template-covariant</>',
-			],
-			[
-				'Parameter #1 $list of method Bug5372\Foo::takesStrings() expects Bug5372\Collection<int, string>, Bug5372\Collection<int, class-string> given.',
-				72,
-				'Template type T on class Bug5372\Collection is not covariant. Learn more: <fg=cyan>https://phpstan.org/blog/whats-up-with-template-covariant</>',
-			],
-			[
-				'Parameter #1 $list of method Bug5372\Foo::takesStrings() expects Bug5372\Collection<int, string>, Bug5372\Collection<int, literal-string> given.',
-				81,
-				'Template type T on class Bug5372\Collection is not covariant. Learn more: <fg=cyan>https://phpstan.org/blog/whats-up-with-template-covariant</>',
-			],
-			[
-				'Parameter #1 $list of method Bug5372\Foo::takesStrings() expects Bug5372\Collection<int, string>, Bug5372\Collection<int, literal-string> given.',
-				85,
-				'Template type T on class Bug5372\Collection is not covariant. Learn more: <fg=cyan>https://phpstan.org/blog/whats-up-with-template-covariant</>',
-			],
-		]);
+		$this->analyse([__DIR__ . '/data/bug-5372.php'], []);
 	}
 
 	public function testLiteralString(): void
@@ -2641,11 +2609,6 @@ public function testGenericVariance(): void
 				'Parameter #1 $param of method GenericVarianceCall\Foo::invariant() expects GenericVarianceCall\Invariant<GenericVarianceCall\B>, GenericVarianceCall\Invariant<GenericVarianceCall\A> given.',
 				45,
 			],
-			[
-				'Parameter #1 $param of method GenericVarianceCall\Foo::invariant() expects GenericVarianceCall\Invariant<GenericVarianceCall\B>, GenericVarianceCall\Invariant<GenericVarianceCall\C> given.',
-				53,
-				'Template type T on class GenericVarianceCall\Invariant is not covariant. Learn more: <fg=cyan>https://phpstan.org/blog/whats-up-with-template-covariant</>',
-			],
 			[
 				'Parameter #1 $param of method GenericVarianceCall\Foo::covariant() expects GenericVarianceCall\Covariant<GenericVarianceCall\B>, GenericVarianceCall\Covariant<GenericVarianceCall\A> given.',
 				60,
@@ -2654,11 +2617,6 @@ public function testGenericVariance(): void
 				'Parameter #1 $param of method GenericVarianceCall\Foo::contravariant() expects GenericVarianceCall\Contravariant<GenericVarianceCall\B>, GenericVarianceCall\Contravariant<GenericVarianceCall\C> given.',
 				83,
 			],
-			[
-				'Parameter #1 $param of method GenericVarianceCall\Foo::invariantArray() expects array{GenericVarianceCall\Invariant<GenericVarianceCall\B>}, array{GenericVarianceCall\Invariant<GenericVarianceCall\C>} given.',
-				97,
-				'Offset 0 (GenericVarianceCall\Invariant<GenericVarianceCall\B>) does not accept type GenericVarianceCall\Invariant<GenericVarianceCall\C>: Template type T on class GenericVarianceCall\Invariant is not covariant. Learn more: <fg=cyan>https://phpstan.org/blog/whats-up-with-template-covariant</>',
-			],
 		]);
 	}
 

tests/PHPStan/Rules/Methods/ReturnTypeRuleTest.php

@@ -469,28 +469,7 @@ public function testInferArrayKey(): void
 
 	public function testBug4590(): void
 	{
-		$this->analyse([__DIR__ . '/data/bug-4590.php'], [
-			[
-				'Method Bug4590\OkResponse::testGenericStatic() should return static(Bug4590\OkResponse<array<string, string>>) but returns static(Bug4590\OkResponse<array{ok: string}>).',
-				36,
-				'Template type T on class Bug4590\OkResponse is not covariant. Learn more: <fg=cyan>https://phpstan.org/blog/whats-up-with-template-covariant</>',
-			],
-			[
-				'Method Bug4590\\Controller::test1() should return Bug4590\\OkResponse<array<string, string>> but returns Bug4590\\OkResponse<array{ok: string}>.',
-				47,
-				'Template type T on class Bug4590\OkResponse is not covariant. Learn more: <fg=cyan>https://phpstan.org/blog/whats-up-with-template-covariant</>',
-			],
-			[
-				'Method Bug4590\\Controller::test2() should return Bug4590\\OkResponse<array<int, string>> but returns Bug4590\\OkResponse<array{string}>.',
-				55,
-				'Template type T on class Bug4590\OkResponse is not covariant. Learn more: <fg=cyan>https://phpstan.org/blog/whats-up-with-template-covariant</>',
-			],
-			[
-				'Method Bug4590\\Controller::test3() should return Bug4590\\OkResponse<array<string>> but returns Bug4590\\OkResponse<array{string}>.',
-				63,
-				'Template type T on class Bug4590\OkResponse is not covariant. Learn more: <fg=cyan>https://phpstan.org/blog/whats-up-with-template-covariant</>',
-			],
-		]);
+		$this->analyse([__DIR__ . '/data/bug-4590.php'], []);
 	}
 
 	public function testTemplateStringBound(): void

tests/PHPStan/Type/Generic/GenericObjectTypeTest.php

@@ -295,7 +295,7 @@ public static function dataAccepts(): array
 			'same class, different type args' => [
 				new GenericObjectType(A\A::class, [new ObjectType('DateTimeInterface')]),
 				new GenericObjectType(A\A::class, [new ObjectType('DateTime')]),
-				TrinaryLogic::createNo(),
+				TrinaryLogic::createYes(),
 			],
 			'same class, one naked' => [
 				new GenericObjectType(A\A::class, [new ObjectType('DateTimeInterface')]),
@@ -310,7 +310,7 @@ public static function dataAccepts(): array
 			'implementation with @extends with different type args' => [
 				new GenericObjectType(B\I::class, [new ObjectType('DateTimeInterface')]),
 				new GenericObjectType(B\IImpl::class, [new ObjectType('DateTime')]),
-				TrinaryLogic::createNo(),
+				TrinaryLogic::createYes(),
 			],
 			'generic object accepts normal object of same type' => [
 				new GenericObjectType(Traversable::class, [new MixedType(true), new ObjectType('DateTimeInterface')]),
@@ -330,8 +330,18 @@ public static function dataAccepts(): array
 		];
 	}
 
+	public static function dataAcceptsTypeProjections(): array
+	{
+		$data = self::dataTypeProjections();
+		// In accepts context, invariant generics accept subtypes (covariant behavior)
+		// Entry #2: [$invariantB, $invariantC, No] → Yes because C extends B
+		$data[2][2] = TrinaryLogic::createYes();
+
+		return $data;
+	}
+
 	#[DataProvider('dataAccepts')]
-	#[DataProvider('dataTypeProjections')]
+	#[DataProvider('dataAcceptsTypeProjections')]
 	public function testAccepts(
 		Type $acceptingType,
 		Type $acceptedType,

tests/PHPStan/Type/StaticTypeTest.php

@@ -391,7 +391,7 @@ public static function dataAccepts(): iterable
 				new StringType(),
 			])], null, []),
 			new GenericStaticType($c, [new IntegerType()], null, []),
-			TrinaryLogic::createNo(),
+			TrinaryLogic::createYes(),
 		];
 
 		yield [