gangster / code-refactor-exercise

Code Refactor Exercise

Project Summary

This project entailed a comprehensive refactor of the executeStandardPTOperations function in a Node.js environment, focusing on enhancing code quality, particularly in the context of RDS database transactions. The objective was to improve the codebase across readability, maintainability, testability, and architecture.

Requirements

• Objective: Refactor and unit test the executeStandardPTOperations function.
• Key Areas: Emphasis on readability, maintainability, testability, and understandability.
• Testing: Implement mocking for RDS calls and ensure comprehensive unit test coverage.

Assumptions

• Language: TypeScript, chosen for type safety.
• Environment: Node.js runtime.
• Database Details: Database schema specifics deemed non-critical.
• Transactional Handling: External management of transactions.
• Testing Aim: Behavioral validation of executeStandardPTOperations.

Technical Approach

TypeScript Integration

• Type Safety: Early detection of errors, proper data structure usage, and correct parameter passing.
• Developer Experience: Tooling support such as autocompletion and informative error messages.
• Readability and Maintainability: Clear type annotations for better code comprehension and maintenance.

Separation of Concerns

• Modular Structure: Specific database functions like insertPayment for focused database interaction.
• Database Interaction Abstraction: The DB interface simplifies the business logic by abstracting SQL query construction.
• Input Validation with Zod: Ensures data integrity before processing.
• Configuration Management: Independent management of environmental variables.
• Testing Isolation: Unit tests written in separate files, targeting individual components.

Testability Enhancements

• Modular Design: Facilitates isolated testing of smaller components.
• Defined Inputs/Outputs: Simplifies test creation and understanding.
• Mocking External Dependencies: Enables behavior testing without real database dependencies.
• Robust Error Handling: Supports testing under varied failure scenarios.
• Stateless Design: Reduces complexity in test setup and cleanup.

Design Patterns

• Factory Pattern: Used in creating database operations, enhancing modularity.
• Module Pattern: TypeScript modules for cohesive and encapsulated code organization.
• Strategy Pattern: Demonstrated in interchangeable database operations.
• Facade Pattern: DB interface acts as a simplified gateway to complex database logic.

Code Quality

• ESLint: Used for enforcing coding standards and identifying potential issues.
• Automated Testing: Continuous quality checks and prevention of regression errors.
• Performance Optimization: Focused on database interaction efficiency and response times.
• Scalability Considerations: Modular and abstracted design for easy scaling and modifications.