Introduce `ClosureType::isStaticClosure()` by phpstan-bot · Pull Request #5699 · phpstan/phpstan-src

phpstan-bot · 2026-05-18T15:21:56Z

Summary

Introduces isStaticClosure(): TrinaryLogic on ClosureType and CallableParametersAcceptor to track whether a closure is declared with the static keyword. This enables PHPStan to distinguish static from non-static closures in the type system, which is useful for rules that check closure binding compatibility and for narrowing the return types of Closure::bindTo() and Closure::bind().

Changes

Core type system

Added isStatic parameter (defaulting to Maybe) to ClosureType constructor (src/Type/ClosureType.php)
Added isStaticClosure(): TrinaryLogic method to ClosureType
Updated ClosureType::equals() to compare isStatic
Updated ClosureType::describe() to show static prefix at precise level and static/non-static at cache level
Updated ClosureType::traverse() and traverseSimultaneously() to preserve isStatic

Interface and implementations

Added isStaticClosure(): TrinaryLogic to CallableParametersAcceptor interface (src/Reflection/Callables/CallableParametersAcceptor.php)
Implemented in all concrete classes:
- CallableType — returns Maybe (callable could be anything)
- TrivialParametersAcceptor — returns Maybe
- FunctionCallableVariant — returns No (named functions are not closures)
- InaccessibleMethod — returns No
- ExtendedCallableFunctionVariant — propagated via constructor parameter
- ResolvedFunctionVariantWithCallable — propagated via constructor parameter

Closure creation

Updated ClosureTypeResolver to pass TrinaryLogic::createFromBoolean($expr->static) at all three ClosureType construction sites (src/Analyser/ExprHandler/Helper/ClosureTypeResolver.php)
Updated InitializerExprTypeResolver to set isStatic: TrinaryLogic::createYes() for static closures in constant contexts (src/Reflection/InitializerExprTypeResolver.php)

Propagation

ParametersAcceptorSelector — propagates isStaticClosure when combining/wrapping callable variants (src/Reflection/ParametersAcceptorSelector.php)
GenericParametersAcceptorResolver — propagates through template resolution (src/Reflection/GenericParametersAcceptorResolver.php)
ClosureFromCallableDynamicReturnTypeExtension — propagates from variant to new ClosureType
TypeNodeResolver — propagates when overriding ClosureType with PHPDoc
RuleLevelHelper — propagates when transforming closure types
CallableTypeHelper::isParametersAcceptorSuperTypeOf() — checks isStaticClosure compatibility

Root cause

The issue requested tracking whether a closure is static in the type system. Previously, the static keyword on closures was only tracked at the AST level ($expr->static) and used for scope resolution (preventing $this access), but was not represented in ClosureType. This meant rules and return type extensions that needed to know if a closure was static had to inspect the AST node directly rather than querying the type.

The fix adds isStatic: TrinaryLogic to ClosureType and propagates it through all relevant interfaces and creation sites. The TrinaryLogic three-valued logic (yes/no/maybe) is used because closures from PHPDoc annotations or generic type resolution may have unknown static-ness.

Test

Type inference test (tests/PHPStan/Analyser/nsrt/closure-static-type.php): Verifies static prefix in type descriptions for static closures and arrow functions, verifies Closure::bindTo() and Closure::bind() return null for static closures and Closure for non-static closures, and verifies Closure|null for closures with unknown static-ness.
Unit tests (tests/PHPStan/Type/ClosureTypeTest.php): Tests for isSuperTypeOf() with static/non-static/maybe-static closure combinations, equals() comparisons, describe() output at all verbosity levels, and isStaticClosure() method.
Updated existing tests: degrade-closures.php, bug-7031.php, bug-9764.php, bug-14324.php — updated to expect static prefix for static closures. bug-4734 test updated to expect the new error from calling null returned by Closure::bind() on a static closure.

Fixes phpstan/phpstan#14639

…o()`/`Closure::bind()` return type for static closures - Add `isStaticClosure(): TrinaryLogic` to `CallableParametersAcceptor` interface - Add `isStatic` parameter to `ClosureType` constructor, propagated through `equals()`, `describe()`, `traverse()`, `traverseSimultaneously()` - Show `static` prefix in `describe()` at precise level when closure is definitely static; show `non-static`/`static` at cache level when known - Implement `isStaticClosure()` in all `CallableParametersAcceptor` implementations: `CallableType` (maybe), `TrivialParametersAcceptor` (maybe), `FunctionCallableVariant` (no), `InaccessibleMethod` (no), `ExtendedCallableFunctionVariant` and `ResolvedFunctionVariantWithCallable` (propagated from source) - Set `isStatic` from `$expr->static` in `ClosureTypeResolver` for both `Closure` and `ArrowFunction` AST nodes - Add `isStaticClosure` check to `CallableTypeHelper::isParametersAcceptorSuperTypeOf()` - Propagate `isStaticClosure` through `ParametersAcceptorSelector`, `GenericParametersAcceptorResolver`, `ClosureFromCallableDynamicReturnTypeExtension`, `TypeNodeResolver`, and `RuleLevelHelper` - Narrow `Closure::bindTo()` to return `null` for static closures and `Closure|null` for maybe-static closures - Narrow `Closure::bind()` to return `null` for static closures and `Closure|null` for maybe-static closures - Update existing tests to expect `static` prefix in closure type descriptions

VincentLanglet

Remove all the change to ClosureBindDynamicReturnTypeExtension and ClosureBindToDynamicReturnTypeExtension.

This will be done in another PR

VincentLanglet · 2026-05-19T21:29:17Z

+				return $prefix . $printer->print($selfWithoutParameterNames->toPhpDocNode());
+			},
+			function (): string {
+				$prefix = !$this->isStatic->maybe() ? ($this->isStatic->yes() ? 'static ' : 'non-static ') : '';


There is no reason to use non-static here, we don't use non-pure.

Both commits are pushed. Here's a summary of the changes:

Commit 1: Revert Closure::bindTo()/Closure::bind() return type narrowing

Reverted ClosureBindDynamicReturnTypeExtension and ClosureBindToDynamicReturnTypeExtension to their original state (no static closure checks)

Updated closure-static-type.php test assertions to expect the closure type (not null) from bind/bindTo

Reverted bug-4734 integration test to original 5-error expectation

Commit 2: Use hyphen prefix and extract helper method

Changed prefix from 'static ' to 'static-' (matching pure-Closure convention)

Removed non-static prefix at cache level (consistent with not using non-pure)

Extracted describeWithPrefix() private method, eliminating the duplicated closure body across value, precise, and cache callbacks (cache now falls through to precise)

Updated all test assertion strings from 'static Closure' to 'static-Closure'

VincentLanglet · 2026-05-19T21:31:07Z


 				return $printer->print($selfWithoutParameterNames->toPhpDocNode());
 			},
+			function (): string {


Maybe a private methode could be created to refactor the value and precise level

VincentLanglet · 2026-05-19T21:31:47Z

 				return $printer->print($selfWithoutParameterNames->toPhpDocNode());
 			},
+			function (): string {
+				$prefix = $this->isStatic->yes() ? 'static ' : '';


prefix should be with a -

…r static closures This will be done in a separate PR. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

…` helper - Change prefix from `static ` to `static-` to match the `pure-Closure` convention - Remove `non-static` prefix at cache level (consistent with not using `non-pure`) - Extract `describeWithPrefix()` private method to deduplicate value/precise callbacks Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

VincentLanglet · 2026-05-19T22:05:29Z

+		);
+	}
+
+	private function describeWithPrefix(string $prefix): string


I prefer a method which take as param a bool to prefix pure and a bool to prefix static

Pushed. Changed describeWithPrefix(string $prefix) to describeBody(bool $showPure, bool $showStatic) as requested — the method now takes two booleans that control whether to include the pure- and static- prefixes, rather than receiving a pre-computed string. Tests and static analysis both pass.

…ic` booleans Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

VincentLanglet · 2026-05-19T22:16:02Z

+			fn (): string => $this->describeBody(showPure: true, showStatic: false),
+			fn (): string => $this->describeBody(showPure: true, showStatic: true),


Do not use namedParam

Done. Removed the named parameters from the describeBody() calls as requested by the reviewer. Tests and static analysis both pass.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

VincentLanglet

Some AttributeReflectionTest::testAttributeReflections test are failing in PHP 8.5 because the expected output is static-Closure rather than Closure

…tributes Static closures in PHP 8.5 attributes now correctly describe as `static-Closure(...)` at precise verbosity level. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

phpstan-bot · 2026-05-19T22:32:08Z

Pushed. Updated the 6 test expectations in AttributeReflectionTest where static closures in PHP 8.5 attributes now describe as static-Closure(...) instead of Closure(...) at precise verbosity level. All tests and static analysis pass.

VincentLanglet requested changes May 19, 2026

View reviewed changes

phpstan-bot and others added 2 commits May 19, 2026 21:43

Revert Closure::bindTo()/Closure::bind() return type narrowing fo…

eb5202f

…r static closures This will be done in a separate PR. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

VincentLanglet reviewed May 19, 2026

View reviewed changes

Replace describeWithPrefix() string param with showPure/`showStat…

cd04085

…ic` booleans Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

VincentLanglet reviewed May 19, 2026

View reviewed changes

VincentLanglet changed the title ~~Introduce ClosureType::isStaticClosure() and narrow Closure::bindTo()/Closure::bind() return type for static closures~~ Introduce ClosureType::isStaticClosure() May 19, 2026

Remove named parameters from describeBody() calls

792cece

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

VincentLanglet reviewed May 19, 2026

View reviewed changes

Update AttributeReflectionTest expectations for static closures in at…

86e8a15

…tributes Static closures in PHP 8.5 attributes now correctly describe as `static-Closure(...)` at precise verbosity level. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

VincentLanglet approved these changes May 19, 2026

View reviewed changes

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Introduce `ClosureType::isStaticClosure()`#5699

Introduce `ClosureType::isStaticClosure()`#5699
phpstan-bot wants to merge 6 commits into
phpstan:2.1.xfrom
phpstan-bot:create-pull-request/patch-hguxjyq

phpstan-bot commented May 18, 2026 •

edited by VincentLanglet

Loading

Uh oh!

VincentLanglet left a comment

Uh oh!

VincentLanglet May 19, 2026

Uh oh!

phpstan-bot May 19, 2026

Uh oh!

VincentLanglet May 19, 2026

Uh oh!

VincentLanglet May 19, 2026

Uh oh!

VincentLanglet May 19, 2026

Uh oh!

phpstan-bot May 19, 2026

Uh oh!

VincentLanglet May 19, 2026

Uh oh!

phpstan-bot May 19, 2026

Uh oh!

VincentLanglet left a comment

Uh oh!

phpstan-bot commented May 19, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

		fn (): string => $this->describeBody(showPure: true, showStatic: false),
		fn (): string => $this->describeBody(showPure: true, showStatic: true),

Conversation

phpstan-bot commented May 18, 2026 • edited by VincentLanglet Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Summary

Changes

Core type system

Interface and implementations

Closure creation

Propagation

Root cause

Test

Uh oh!

VincentLanglet left a comment

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

VincentLanglet left a comment

Choose a reason for hiding this comment

Uh oh!

phpstan-bot commented May 19, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

phpstan-bot commented May 18, 2026 •

edited by VincentLanglet

Loading