Fix #1155: Refactor TaskExecutor to reduce complexity and improve maintainability

[trivikramkalagi91-commits]

Description

This PR refactors the TaskExecutor component in backend/secuscan/executor.py to reduce complexity and improve maintainability.

Changes Made

• Extracted guardrail validation logic into _enforce_guardrails()
• Extracted Docker network setup logic into _ensure_docker_network()
• Extracted modular scanner execution into _execute_modular_scanner()
• Extracted standard scanner execution into _execute_standard_scanner()
• Improved code readability through better separation of concerns
• Added type hints and documentation for extracted helper methods
• Added unit tests covering the new helper methods

This refactor preserves existing functionality while making the execution flow easier to understand, maintain, and test.

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Related Issues

Fixes #1155

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Type of Change

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

Note: This is primarily a code refactoring/maintenance improvement with no functional changes.

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How Has This Been Tested?

Unit Tests

.\venv\Scripts\pytest testing/backend/unit/test_executor.py

Result:

27 passed

Integration Tests

.\venv\Scripts\pytest testing/backend/integration/test_docker_hardening.py

Result:

7 passed, 9 skipped

Manual Verification

• Verified standard scanner execution flow remains unchanged.
• Verified modular scanner execution works correctly.
• Verified task status handling remains unchanged.
• Verified findings and reports continue to be persisted correctly.
• Verified no public APIs or database schemas were modified.

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Checklist

• My code follows the code style of this project.
• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas.
• I have made corresponding changes to the documentation.
• My changes generate no new warnings.