Treat all in-scope variables as used when a closure or constructor body contains include/require/eval

[phpstan-bot]

Summary

PHPStan reported Anonymous function has an unused use $container for a closure whose only use of the captured variable happens inside an include/required file. Because the included file executes in the closure's scope, it can reference any captured variable, so the use is not actually unused. This is a common pattern (used in phpstan-src itself, CommandHelper::executeBootstrapFile()) to isolate the include scope from surrounding locals.

The fix teaches UnusedFunctionParametersCheck that an include/require/eval in the body may consume any in-scope variable, so no unused-use / unused-parameter error should be reported for them.

Changes

• src/Rules/UnusedFunctionParametersCheck.php: in getUsedVariables(), when a Node\Expr\Include_ (include/include_once/require/require_once) or Node\Expr\Eval_ node is encountered, return $scope->getDefinedVariables() — the same short-circuit already used for func_get_args(), get_defined_vars() and compact().
• tests/PHPStan/Rules/Functions/data/unused-closure-uses.php + test: added closures capturing $container used only via require_once, include and eval.
• tests/PHPStan/Rules/Classes/data/unused-constructor-parameters-include.php + test: added a constructor whose parameter is used only inside a require_onced file (the analogous constructor.unusedParameter rule, which shares the same check).

Root cause

getUsedVariables() walks the AST collecting referenced variable names, and a variable used only inside an included file or eval'd string is invisible to that walk. The established remedy for constructs that can reference arbitrary in-scope variables (func_get_args, get_defined_vars, compact) is to return all defined variables so nothing is flagged. include/require and eval belong to that same family and were missing.

The pattern affects both rules built on UnusedFunctionParametersCheck:

• UnusedClosureUsesRule (closure.unusedUse)
• UnusedConstructorParametersRule (constructor.unusedParameter)

Both are fixed by the single change since they share getUsedVariables().

Test

• UnusedClosureUsesRuleTest: closures capturing $container and using it only through require_once, include and eval no longer report closure.unusedUse. Verified the test fails before the fix.
• UnusedConstructorParametersRuleTest::testParameterUsedInIncludedFile: a constructor parameter used only inside a require_onced file no longer reports constructor.unusedParameter. Verified this analogous case also failed before the fix and passes after.

Fixes phpstan/phpstan#14962

[staabm]

remaining CI errors are unrelated

edit: fixed in #6057