Add an integration test case for generic variance

Author: jiripudil

tests/PHPStan/Rules/Methods/CallMethodsRuleTest.php

@@ -2512,6 +2512,32 @@ public function testGenericsInferCollectionLevel8(): void
 ]);
 }
 
+public function testGenericVariance(): void
+{
+$this->checkThisOnly = false;
+$this->checkNullables = true;
+$this->checkUnionTypes = true;
+$this->checkExplicitMixed = false;
+$this->analyse([__DIR__ . '/data/generic-variance.php'], [
+[
+'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,
+],
+[
+'Parameter #1 $param of method GenericVarianceCall\Foo::covariant() expects GenericVarianceCall\Covariant<GenericVarianceCall\B>, GenericVarianceCall\Covariant<GenericVarianceCall\A> given.',
+60,
+],
+[
+'Parameter #1 $param of method GenericVarianceCall\Foo::contravariant() expects GenericVarianceCall\Contravariant<GenericVarianceCall\B>, GenericVarianceCall\Contravariant<GenericVarianceCall\C> given.',
+83,
+],
+]);
+}
+
 public function testBug6904(): void
 {
 if (PHP_VERSION_ID < 80100) {

tests/PHPStan/Rules/Methods/data/generic-variance.php

@@ -0,0 +1,85 @@
+<?php
+
+namespace GenericVarianceCall;
+
+class A {}
+class B extends A {}
+class C extends B {}
+
+/** @template T */
+class Invariant {}
+
+/** @template-covariant T */
+class Covariant {}
+
+/** @template-contravariant T */
+class Contravariant {}
+
+class Foo
+{
+/**
+ * @param Invariant<B> $param
+ */
+public function invariant(Invariant $param): void
+{
+}
+
+/**
+ * @param Covariant<B> $param
+ */
+public function covariant(Covariant $param): void
+{
+}
+
+/**
+ * @param Contravariant<B> $param
+ */
+public function contravariant(Contravariant $param): void
+{
+}
+
+public function testInvariant(): void
+{
+/** @var Invariant<A> $invariantA */
+$invariantA = new Invariant();
+$this->invariant($invariantA);
+
+/** @var Invariant<B> $invariantB */
+$invariantB = new Invariant();
+$this->invariant($invariantB);
+
+/** @var Invariant<C> $invariantC */
+$invariantC = new Invariant();
+$this->invariant($invariantC);
+}
+
+public function testCovariant(): void
+{
+/** @var Covariant<A> $covariantA */
+$covariantA = new Covariant();
+$this->covariant($covariantA);
+
+/** @var Covariant<B> $covariantB */
+$covariantB = new Covariant();
+$this->covariant($covariantB);
+
+/** @var Covariant<C> $covariantC */
+$covariantC = new Covariant();
+$this->covariant($covariantC);
+}
+
+public function testContravariant(): void
+{
+/** @var Contravariant<A> $contravariantA */
+$contravariantA = new Contravariant();
+$this->contravariant($contravariantA);
+
+/** @var Contravariant<B> $contravariantB */
+$contravariantB = new Contravariant();
+$this->contravariant($contravariantB);
+
+/** @var Contravariant<C> $contravariantC */
+$contravariantC = new Contravariant();
+$this->contravariant($contravariantC);
+}
+}