`closureUsesThis` should not be reported when `@param-closure-this` is used to change the `$this`

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Assessment

Difficulty
4/5
Estimated time
3-5 days
Newbie friendliness
35/100
Issue type
Bug
Clarity
Mostly clear
Activity status
Stale
Tech stack
php
Domain
tooling

Research direction

Start by reproducing the provided Macroable and SpecialScope example and inspect the closureUsesThis rule. The fix is done when @param-closure-this changing the closure's $this type prevents this diagnostic for the captured outer $this, while the existing warning remains for matching types.

Written by the indexing model from the issue text.

Description

Hello!

When using macros, the $this parameter inside the provided closure is overridden using @param-closure-this:

trait Macroable
{
    /**
     * Register a custom macro.
     *
     * @param-closure-this $this $macro
     */
    public static function macro(string $name, Closure $macro): void;
}
class Builder
{
    use Macroable;
}

However, in some cases, the original class $this needs to be referenced inside the closure:

class SpecialScope
{
    protected function addOnlyConfidential(Builder $query): void
    {
        $scope = $this;

        $query->macro('onlyConfidential', function (Builder $query) use ($scope) {
            $query->withoutGlobalScope($scope);

            return $query->where($scope->column, $scope->invert ? false : true);
        });
    }
}

But this triggers the closureUsesThis rule:

Anonymous function uses $this assigned to variable $scope. Use $this directly in the function body.  
         🪪  closure.useThis

The rule probably shouldn't be triggered if the $this type outside the closure does not match the type inside the closure

Dominant language
PHP
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Merged PRs (30d)
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