Support null templates

Author: SplotyCode

src/Rules/Generics/TemplateTypeCheck.php

@@ -28,6 +28,7 @@
 use PHPStan\Type\IterableType;
 use PHPStan\Type\KeyOfType;
 use PHPStan\Type\MixedType;
+use PHPStan\Type\NullType;
 use PHPStan\Type\ObjectShapeType;
 use PHPStan\Type\ObjectType;
 use PHPStan\Type\ObjectWithoutClassType;
@@ -132,6 +133,7 @@ public function check(
 				&& $boundTypeClass !== GenericObjectType::class
 				&& $boundTypeClass !== KeyOfType::class
 				&& $boundTypeClass !== IterableType::class
+				&& $boundTypeClass !== NullType::class
 				&& !$boundType instanceof UnionType
 				&& !$boundType instanceof IntersectionType
 				&& !$boundType instanceof TemplateType

tests/PHPStan/Analyser/AnalyserIntegrationTest.php

@@ -1496,7 +1496,7 @@ public function testBug12979(): void
 
 	public function testBug12095(): void
 	{
-		$errors = $this->runAnalyse(__DIR__ . '/data/bug-12095.php');
+		$errors = $this->runAnalyse(__DIR__ . '/nsrt/bug-12894.php');
 		$this->assertNoErrors($errors);
 	}
 

tests/PHPStan/Analyser/nsrt/bug-12894.php

@@ -1,18 +1,25 @@
-<?php declare(strict_types = 1);
+<?php declare(strict_types = 1); // lint >= 8.0
 
 namespace Bug12894;
 
+use Closure;
+
 /**
  * @template TValue of object|null
  */
-interface Dependency {
+interface Dependency
+{
+
 	/**
 	 * @return TValue
 	 */
 	public function __invoke(): object|null;
+
 }
 
-interface DependencyResolver {
+interface DependencyResolver
+{
+
 	/**
 	 * @template V of object|null
 	 * @template D of Dependency<V>
@@ -22,25 +29,23 @@ interface DependencyResolver {
 	 * @return V
 	 */
 	public function resolve(Dependency $dependency): object|null;
+
 }
 
-/**
- * @internal
- */
-class Resolver implements DependencyResolver {
-	public function __construct(
-		/**
-		 * @var Closure(object|null): void
-		 */
-		protected readonly Closure $run,
-	) {
-		// empty
-	}
+class Resolver implements DependencyResolver
+{
+	/**
+	 * @var Closure(object|null): void
+	 */
+	protected Closure $run;
 
 	public function resolve(Dependency $dependency): object|null {
 		$resolved = $dependency();
+		\PHPStan\Testing\assertType('V of object|null (method Bug12894\DependencyResolver::resolve(), argument)', $resolved);
 		$result = is_object($resolved) ? 1 : 2;
+		\PHPStan\Testing\assertType('V of object (method Bug12894\DependencyResolver::resolve(), argument)|V of null (method Bug12894\DependencyResolver::resolve(), argument)', $resolved);
 		($this->run)($resolved);
 		return $resolved;
 	}
+
 }

tests/PHPStan/Analyser/nsrt/bug-12989.php

@@ -10,8 +10,8 @@
 function a(?int $b): ?int
 {
 	if ($b === null) {
+		\PHPStan\Testing\assertType('T of null (function Bug12989\a(), argument)', $b);
 		return $b;
 	}
 	return $b;
 }
-

tests/PHPStan/Analyser/nsrt/template-null-bound.php

@@ -17,10 +17,20 @@ public function doFoo(?int $p): ?int
 		return $p;
 	}
 
+	/**
+	 * @template T of null
+	 * @return T
+	 */
+	public function nullTemplate(): mixed
+	{
+		return null;
+	}
+
 }
 
 function (Foo $f, ?int $i): void {
 	assertType('null', $f->doFoo(null));
 	assertType('1', $f->doFoo(1));
 	assertType('int|null', $f->doFoo($i));
+	assertType('null', $f->nullTemplate());
 };

tests/PHPStan/Rules/Generics/FunctionTemplateTypeRuleTest.php

@@ -56,10 +56,6 @@ public function testRule(): void
 				'PHPDoc tag @template T for function FunctionTemplateType\resourceBound() with bound type resource is not supported.',
 				50,
 			],
-			[
-				'PHPDoc tag @template T for function FunctionTemplateType\nullNotSupported() with bound type null is not supported.',
-				68,
-			],
 			[
 				'Call-site variance of covariant int in generic type FunctionTemplateType\GenericCovariant<covariant int> in PHPDoc tag @template U is redundant, template type T of class FunctionTemplateType\GenericCovariant has the same variance.',
 				94,

tests/PHPStan/Rules/Generics/data/function-template.php

@@ -65,7 +65,7 @@ function nakano()
 }
 
 /** @template T of null */
-function nullNotSupported()
+function nullSupported()
 {
 
 }

tests/PHPStan/Rules/PhpDoc/IncompatiblePhpDocTypeRuleTest.php

@@ -320,10 +320,6 @@ public function testGenericCallables(): void
 				'PHPDoc tag @param for parameter $invalidBoundType template T of Closure<T of GenericCallablesIncompatible\Invalid>(T): T has invalid bound type GenericCallablesIncompatible\Invalid.',
 				25,
 			],
-			[
-				'PHPDoc tag @param for parameter $notSupported template T of Closure<T of null>(T): T with bound type null is not supported.',
-				32,
-			],
 			[
 				'PHPDoc tag @param for parameter $shadows template T of Closure<T of mixed>(T): T shadows @template T for function GenericCallablesIncompatible\testShadowFunction.',
 				40,
@@ -360,10 +356,6 @@ public function testGenericCallables(): void
 				'PHPDoc tag @return template T of Closure<T of GenericCallablesIncompatible\Invalid>(T): T has invalid bound type GenericCallablesIncompatible\Invalid.',
 				90,
 			],
-			[
-				'PHPDoc tag @return template T of Closure<T of null>(T): T with bound type null is not supported.',
-				97,
-			],
 			[
 				'PHPDoc tag @return template T of Closure<T of mixed>(T): T shadows @template T for function GenericCallablesIncompatible\testShadowFunctionReturn.',
 				105,
@@ -380,10 +372,6 @@ public function testGenericCallables(): void
 				'PHPDoc tag @param for parameter $invalidBoundType template T of Closure<T of GenericCallablesIncompatible\Invalid>(T): T has invalid bound type GenericCallablesIncompatible\Invalid.',
 				131,
 			],
-			[
-				'PHPDoc tag @param for parameter $notSupported template T of Closure<T of null>(T): T with bound type null is not supported.',
-				138,
-			],
 			[
 				'PHPDoc tag @return template of Closure<stdClass of mixed>(stdClass): stdClass cannot have existing class stdClass as its name.',
 				145,
@@ -396,10 +384,6 @@ public function testGenericCallables(): void
 				'PHPDoc tag @return template T of Closure<T of GenericCallablesIncompatible\Invalid>(T): T has invalid bound type GenericCallablesIncompatible\Invalid.',
 				159,
 			],
-			[
-				'PHPDoc tag @return template T of Closure<T of null>(T): T with bound type null is not supported.',
-				166,
-			],
 			[
 				'PHPDoc tag @param-out for parameter $existingClass template T of Closure<T of mixed>(T): T shadows @template T for function GenericCallablesIncompatible\shadowsParamOut.',
 				175,

tests/PHPStan/Rules/PhpDoc/IncompatiblePropertyPhpDocTypeRuleTest.php

@@ -186,10 +186,6 @@ public function testGenericCallables(): void
 				'PHPDoc tag @var template of callable<TypeAlias of mixed>(TypeAlias): TypeAlias cannot have existing type alias TypeAlias as its name.',
 				26,
 			],
-			[
-				'PHPDoc tag @var template TNull of callable<TNull of null>(TNull): TNull with bound type null is not supported.',
-				31,
-			],
 			[
 				'PHPDoc tag @var template TInvalid of callable<TInvalid of GenericCallableProperties\Invalid>(TInvalid): TInvalid has invalid bound type GenericCallableProperties\Invalid.',
 				36,

tests/PHPStan/Rules/PhpDoc/data/generic-callables-incompatible.php

@@ -27,9 +27,9 @@ function invalidBoundType(Closure $invalidBoundType): void
 }
 
 /**
- * @param Closure<T of null>(T $val): T $notSupported
+ * @param Closure<T of null>(T $val): T $closure
  */
-function notSupported(Closure $notSupported): void
+function testNull(Closure $closure): void
 {
 }
 
@@ -94,7 +94,7 @@ function invalidBoundTypeReturn(): Closure
 /**
  * @return Closure<T of null>(T $val): T
  */
-function notSupportedReturn(): Closure
+function nullReturn(): Closure
 {
 }
 
@@ -133,9 +133,9 @@ public function invalidBoundType(Closure $invalidBoundType): void
 	}
 
 	/**
-	 * @param Closure<T of null>(T $val): T $notSupported
+	 * @param Closure<T of null>(T $val): T $closure
 	 */
-	public function notSupported(Closure $notSupported): void
+	public function nullType(Closure $closure): void
 	{
 	}
 
@@ -163,7 +163,7 @@ public function invalidBoundTypeReturn(): Closure
 	/**
 	 * @return Closure<T of null>(T $val): T
 	 */
-	public function notSupportedReturn(): Closure
+	public function nullReturn(): Closure
 	{
 	}
 }