Consider static<T, U> same as static when the template types match

Author: ondrejmirtes

src/PhpDoc/TypeNodeResolver.php

@@ -65,6 +65,7 @@
 use PHPStan\Type\FloatType;
 use PHPStan\Type\Generic\GenericClassStringType;
 use PHPStan\Type\Generic\GenericObjectType;
+use PHPStan\Type\Generic\TemplateType;
 use PHPStan\Type\Generic\TemplateTypeVariance;
 use PHPStan\Type\Helper\GetTemplateTypeType;
 use PHPStan\Type\IntegerRangeType;
@@ -758,6 +759,29 @@ static function (string $variance): TemplateTypeVariance {
 
 			$classReflection = $this->getReflectionProvider()->getClass($mainTypeClassName);
 			if ($classReflection->isGeneric()) {
+				if ($mainTypeName === 'static') {
+					$templateTags = $classReflection->getTemplateTags();
+					$templateTypeMap = $classReflection->getTemplateTypeMap();
+					if (count($genericTypes) === $templateTypeMap->count()) {
+						$templateTypeList = $classReflection->typeMapToList($templateTypeMap);
+						foreach ($genericTypes as $i => $genericType) {
+							if (!$genericType instanceof TemplateType) {
+								break;
+							}
+							$templateType = $templateTypeList[$i];
+							if (!$templateType instanceof TemplateType) {
+								break;
+							}
+							if ($templateType->getName() !== $genericType->getName()) {
+								break;
+							}
+							unset($templateTags[$genericType->getName()]);
+						}
+						if (count($templateTags) === 0) {
+							return new StaticType($classReflection);
+						}
+					}
+				}
 				if (in_array($mainTypeClassName, [
 					Traversable::class,
 					IteratorAggregate::class,

tests/PHPStan/Analyser/NodeScopeResolverTest.php

@@ -149,6 +149,7 @@ public function dataFileAsserts(): iterable
 		yield from $this->gatherAssertTypes(__DIR__ . '/../Reflection/data/staticReturnType.php');
 
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/minmax.php');
+		yield from $this->gatherAssertTypes(__DIR__ . '/data/consistent-static.php');
 		if (PHP_VERSION_ID < 80000) {
 			yield from $this->gatherAssertTypes(__DIR__ . '/data/minmax-arrays.php');
 		}

tests/PHPStan/Analyser/data/consistent-static.php

@@ -0,0 +1,58 @@
+<?php
+
+namespace ConsistentStaticGenerics;
+
+use function PHPStan\Testing\assertType;
+
+/**
+ * @template T
+ * @template U
+ */
+class Foo
+{
+
+	/**
+	 * @return static
+	 */
+	public function doFoo(): self
+	{
+
+	}
+
+	/**
+	 * @return static<T, U>
+	 */
+	public function doBar(): self
+	{
+
+	}
+
+	/**
+	 * @return static<T>
+	 */
+	public function doBaz(): self
+	{
+
+	}
+
+	/**
+	 * @return static<U, T>
+	 */
+	public function doLorem(): self
+	{
+
+	}
+
+}
+
+class Bar extends Foo
+{
+
+}
+
+function (Bar $bar): void {
+	assertType(Bar::class, $bar->doFoo());
+	assertType(Bar::class, $bar->doBar());
+	assertType('ConsistentStaticGenerics\Foo<mixed>', $bar->doBaz()); // the definition should error
+	assertType('ConsistentStaticGenerics\Foo<mixed, mixed>', $bar->doLorem());
+};