🧮 feat: Improve structured token spending and testing; fix: Anthropic Cache Spend

[danny-avila]

Summary

I implemented improvements in the structured token spending functionality and added comprehensive unit tests. The changes include:

• Updated the calculateStructuredTokenValue method in the Transaction model to handle negative token values and ensure correct rate calculations.
• Improved the spendStructuredTokens function to correctly handle negative token counts for prompt tokens.
• Added extensive unit tests for both regular and structured token spending scenarios.
• Updated the logging in spendTokens and spendStructuredTokens to provide more detailed information about transactions.
• Refactored the spendTokens function to always record transactions, even when token counts are zero.
• Fixed an edge case where the balance could incorrectly increase for certain Anthropic model transactions.
• Updated the Jest and mongodb-memory-server dependencies to their latest versions for improved testing capabilities.

Testing

To test these changes:

1. Run the unit tests using npm test in the api directory.
2. Manually test token spending scenarios in the application, particularly with Anthropic models and structured token spending.
3. Verify that the balance updates correctly for various token usage scenarios.
4. Check the logs to ensure that transaction details are being recorded accurately.

Test Configuration:

• Node.js environment
• MongoDB instance (using mongodb-memory-server for tests)
• Updated Jest version 29.7.0
• Various token spending scenarios, including edge cases with zero or negative token counts

Checklist

• My code adheres to this project's style guidelines
• I have performed a self-review of my own code
• I have commented in any complex areas of my code
• I have made pertinent documentation changes
• My changes do not introduce new warnings
• I have written tests demonstrating that my changes are effective or that my feature works
• Local unit tests pass with my changes