Description

Hello. I'm a regular user and a big fan of this wonderful library.
I would like to propose an improvement.

The Current Problem

Currently, the validation Rules for GraphQL are managed in a global scope shared across the entire library. However, with the recent addition of features like Replace Rule, these global rules can now be modified at runtime.

This implementation can cause the following issues in a concurrent environment:

• Race conditions can occur, leading to unintended modifications of the rules.
• As a result, the set of rules used for validation can become unpredictable, causing unstable behavior.

Proposed Solution

As a first step to resolve this, I would like to refactor the way rules are managed. Specifically, I propose to stop managing rules with a global variable and instead introduce a new, dedicated Rules struct to handle them.

This will allow each validation process to have its own isolated set of rules, making it safe to manipulate them in a concurrent environment.

Changes in this Pull Request

As the first step toward implementing the solution above, this pull request introduces the following changes:

• Introduces the new Rules struct.
• Creates a new core directory and places the Rules struct there to avoid package import cycles.

Future Plans

Once this pull request is successfully merged, the next step is to add new Validate and LoadQuery functions that do not rely on the global rules. To maintain backward compatibility, these will be provided as new, separate functions.

Thank you for your consideration.

relates to

#380

I have:

• Added tests covering the bug / feature
• Updated any relevant documentation