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Visual Testing Script Refactoring Strategy

Current Architecture Overview

Core Components

  1. VisualTester Class
  2. Responsible for setting up, executing, and tearing down visual tests
  3. Key methods:

    • setup(): Builds documentation and starts local server
    • teardown(): Stops local server
    • capture_page(): Takes screenshots of individual pages
    • test_navigation(): Performs navigation menu testing
  4. Utility Functions

  5. safe_get(): Defensive value retrieval
  6. safe_evaluate(): Safe JavaScript evaluation
  7. print_nav_results(): Result reporting
  8. YAML and navigation parsing utilities

  9. Test Execution Flow

  10. run_tests(): Async function managing test workflow
  11. visual(): Typer CLI entry point

Refactoring Recommendations

1. Separation of Concerns

  • Split the monolithic visual.py into multiple modules:
  • visual/core.py: Core testing logic
  • visual/utils.py: Utility functions
  • visual/cli.py: Command-line interface

2. Error Handling and Logging

  • Implement a more robust logging mechanism
  • Create custom exception classes for different failure modes
  • Add detailed error context and traceability

3. Configuration Management

  • Move hardcoded values to a configuration file
  • Support dynamic configuration for:
  • Server settings
  • Screenshot parameters
  • Timeout values

4. Performance Optimization

  • Implement parallel page capture with better concurrency control
  • Add more granular timeout and retry mechanisms
  • Optimize network request handling

5. Testing Strategy Enhancements

  • Add support for:
  • Responsive design testing
  • Accessibility checks
  • Performance metrics capture

6. Code Quality Improvements

  • Increase type hints and runtime type checking
  • Add comprehensive docstrings
  • Implement more defensive programming techniques

Proposed Refactoring Workflow

  1. Modularization

    # visual/core.py
    class VisualTester:
        # Core testing logic
    
    # visual/utils.py
    def safe_get(...):
        # Utility functions
    
    # visual/cli.py
    def run_visual_tests(...):
        # CLI entry point
    

  2. Enhanced Configuration

    # visual_config.yaml
    server:
      base_url: "http://localhost:8000"
      timeout: 30
    
    screenshot:
      width: 1280
      height: 720
      format: "png"
    
    testing:
      retry_attempts: 3
      parallel_jobs: 4
    

  3. Advanced Error Handling

    class VisualTestError(Exception):
        """Base exception for visual testing"""
        def __init__(self, message, context=None):
            self.context = context
            super().__init__(message)
    
    class NavigationTestFailure(VisualTestError):
        """Specific exception for navigation testing failures"""
    

Performance Metrics and Logging

  • Track and log:
  • Total test duration
  • Per-page capture time
  • Resource utilization
  • Detailed error logs

Future Considerations

  • Integration with CI/CD pipelines
  • Support for multiple browsers
  • Machine learning-assisted visual regression testing

Refining Page Capture Strategy

Current Challenge

Our current page capture mechanism in capture_page_with_advanced_strategy needs refinement to improve: - Code readability - Error handling - Performance - Maintainability

Key Observations

Complexity Factors

  1. Multiple nested try-except blocks
  2. Complex retry logic
  3. Inline configuration for timeout and complexity

Proposed Refactoring Approach

Goals

  • Separate concerns
  • Make code more declarative
  • Improve error traceability
  • Create more testable components

Potential Improvements

  • Extract timeout calculation logic
  • Create explicit error handling strategies
  • Use more descriptive variable names
  • Implement a clear retry mechanism

Next Steps

  1. Analyze current implementation
  2. Break down complex logic into smaller functions
  3. Create clear, single-responsibility methods
  4. Add comprehensive logging
  5. Implement robust error tracking

Guiding Principles

  • Clarity over complexity
  • Explicit over implicit
  • Testability is key
  • Performance matters, but readability first

Conclusion

The current visual testing script provides a solid foundation. Refactoring will improve maintainability, performance, and extensibility.