Add comprehensive testing suite for PositionManager

[TexasCoding]

This pull request introduces a complete testing suite for the PositionManager class found in src/project_x_py/position_manager. It includes several test files that cover key functionalities, including position analytics, core methods, risk metrics, and position tracking.

The additions include:

• Fixtures for setting up the testing environment (tests/position_manager/conftest.py).
• Tests for calculating profit and loss, validating positions, and ensuring functionality such as position updates and cache behavior.
• Risk metrics assessments to ensure correct calculations of exposures and diversification.

These tests improve code reliability and maintainability, addressing the need for a structured testing approach as outlined in the associated issue.

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This pull request was co-created with Cosine Genie

Original Task: project-x-py/dzga7th7u7ic
Author: Jeff West

[claude]

Claude finished @TexasCoding's task —— View job

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PR Review: PositionManager Testing Suite

I've thoroughly reviewed this pull request and found several issues that need to be addressed. Here's my comprehensive analysis:

🚨 Critical Issues

1. Test Implementation Bug in test_analytics.py:33

Location: tests/position_manager/test_analytics.py:33

# INCORRECT - This will fail
total_pnl, positions_with_prices = pm.calculate_portfolio_pnl(prices)

Problem: The test assumes calculate_portfolio_pnl() returns a tuple, but the actual implementation returns a dictionary. According to the source code (analytics.py:184-191), it returns:

return {
    "total_pnl": total_pnl,
    "positions_count": len(positions),
    "positions_with_prices": positions_with_prices,
    "positions_without_prices": len(positions) - positions_with_prices,
    "position_breakdown": position_breakdown,
    "timestamp": datetime.now(),
}

Fix Required:

result = await pm.calculate_portfolio_pnl(prices)
total_pnl = result["total_pnl"]
positions_with_prices = result["positions_with_prices"]

2. Missing Async/Await in test_analytics.py

Problem: Line 33 calls pm.calculate_portfolio_pnl(prices) without await, but the method is async.

Fix Required:

result = await pm.calculate_portfolio_pnl(prices)

3. Key Mismatch in Risk Metrics Test

Location: tests/position_manager/test_risk.py:10-12

# INCORRECT
expected_total_exposure = sum(abs(d["size"]) for d in mock_positions_data)
expected_num_contracts = len(set(d["contractId"] for d in mock_positions_data))
# Later: metrics["num_contracts"] == expected_num_contracts

Problem: The test expects num_contracts but the implementation returns position_count (see risk.py:96).

Fix Required:

assert metrics["position_count"] == expected_num_contracts

4. Incorrect Diversification Formula in Test

Location: tests/position_manager/test_risk.py:13

expected_diversification = (expected_num_contracts - 1) / (expected_num_contracts or 1)

Problem: This doesn't match the actual implementation in risk.py:88-90:

diversification_score = (
    1.0 - largest_position_risk if largest_position_risk < 1.0 else 0.0
)

The test formula is incorrect and will produce wrong expected values.

⚠️ Moderate Issues

5. Inconsistent Return Types

• Analytics: calculate_position_pnl() returns dict but test calls it directly expecting numeric value
• Test expects: Simple numeric return in test_analytics.py:10,15
• Actual returns: Complex dictionary with multiple fields

6. Missing Error Case Testing

• No tests for invalid position data
• No tests for missing price data scenarios
• No tests for edge cases (zero positions, negative prices)

7. Test Coverage Gaps

• Missing tests for calculate_portfolio_pnl() error handling
• No tests for risk warning generation (_generate_risk_warnings)
• Missing integration tests between modules

✅ Positive Aspects

Good Practices Found:

• ✅ Proper use of @pytest.mark.asyncio
• ✅ Good fixture organization in conftest.py
• ✅ Comprehensive mock data setup
• ✅ Clear test structure and naming
• ✅ Tests cover core functionality areas

Code Quality:

• ✅ Clean separation of test modules by functionality
• ✅ Proper async/await usage in most tests
• ✅ Good use of existing fixture patterns

🔧 Recommendations

Immediate Fixes Needed:

1. Fix test_calculate_portfolio_pnl() - Update to handle dict return and add await
2. Fix risk metrics assertions - Use correct return keys
3. Correct diversification calculation - Match actual implementation
4. Add missing await keywords where needed

Suggested Improvements:

1. Add error handling tests for robustness
2. Test edge cases (empty portfolios, invalid data)
3. Add integration tests combining multiple modules
4. Test async behavior more thoroughly

Performance Considerations:

• Tests appear lightweight and should run quickly
• Good use of mocking to avoid external dependencies
• Consider adding performance benchmarks for large portfolios

Security Assessment:

• ✅ No security concerns identified
• Tests properly isolate external dependencies
• Mock data doesn't expose sensitive information

📊 Test Coverage Assessment

Current Coverage: ~60% (estimated)

• ✅ Core methods covered
• ⚠️ Error paths missing
• ⚠️ Edge cases incomplete
• ❌ Integration scenarios absent

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Overall Assessment: The testing suite shows good structure and covers basic functionality, but requires several critical fixes before it can be considered reliable. The async architecture compliance is good, but some implementation details were misunderstood.