error handling in factory contracts

[FrankiePower]

Pull Request: Improve Error Handling in StrapexFactory Contract

feat:error handling in factory contracts

Context

The StrapexFactory contract previously lacked structured error handling, making it difficult to debug and ensure proper execution flow. The suggested approach was to use an Errors module with an enum and #[error_code] attributes. However, this approach does not work due to limitations in the current Cairo version. Instead, we opted for a simpler, more effective solution using const error codes.

This PR enhances the error-handling mechanism while maintaining compatibility with the existing Cairo contract structure.

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Related issue #33

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Changes

1. Implemented Errors Module with Constants

   • Replaced the proposed #[error_code] enum with const values.
   • Ensured all relevant contract functions utilize meaningful error codes.

2. Updated Constructor to Include Additional Validations

   • Prevents deployment with invalid parameters.
   • Ensures non-zero values for owner, childHash, and depositToken.

3. Improved create_strapex_contract Handling

   • Added an explicit check to verify deploy_syscall success.
   • Ensured failed deployments do not proceed further.

4. Enhanced getUserStrapexAccount and get_childClassHash

   • Prevents returning uninitialized values by enforcing checks.
   • Returns a default value when an account does not exist.

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Reasons for Not Using Suggested Approach

• #[error_code] and Enum-Based Error Handling Are Not Supported:

  • The current Cairo version does not support #[error_code] annotations.
  • Using an enum for errors introduces unnecessary complexity when const values suffice.

• Constants Provide a More Readable and Efficient Approach:

  • Direct const values make it easy to reference errors across functions.
  • Reduces overhead associated with enum-to-integer conversions.

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Acceptance Criteria

1. General Improvements:

   • The contract follows a structured approach for error handling.
   • Error codes are used consistently across functions.

2. constructor Function:

   • Rejects invalid owner, hash, or token addresses.
   • Initializes contract state correctly.

3. create_strapex_contract Function:

   • Ensures deploy_syscall succeeds before proceeding.
   • Stores and emits events correctly.

4. getUserStrapexAccount and get_childClassHash Functions:

   • Ensures non-existent accounts return a default value instead of uninitialized data.

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Type of Change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Code refactoring
• Performance improvement

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Testing

• Unit tests added/updated
• Integration tests added/updated
• Manual testing performed

Test Instructions

1. Checkout branch
2. Run pnpm install
3. Additional steps...

Screenshots

Checklist

• My code follows the project's coding style
• I have commented my code, particularly in hard-to-understand areas
• I have updated the documentation accordingly
• My changes generate no new warnings
• New and existing unit tests pass locally
• I have added tests that prove my fix/feature works
• Any dependent changes have been merged and published
• Closes #XX (Reference the corresponding issue if applicable).

Additional Notes

• On scarb build: Verified successful compilation with new error handling.

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[machuwey]

Overall looks good! Nice work @FrankiePower