test: add gas usage tests for updateMiddlewareDataHash (fixes #1)

[RonTuretzky]

Summary

• Added comprehensive gas usage tests for the updateMiddlewareDataHash function to address issue Check that updateMiddlewareDataHash function won't pass gas block limit #1
• Tests confirm that the function will exceed block gas limits under realistic operating conditions
• Documented findings and recommendations for mitigation strategies

Changes

• Created MiddlewareShimGasTest.t.sol with multiple test scenarios:
  • Varying operator counts (10-500)
  • Varying history lengths (5-100)
  • Gas growth rate analysis
  • Worst-case scenario testing
• Added GAS_FINDINGS.md documentation with detailed analysis

Key Findings

Gas Usage Exceeds Block Limits:

• 500 operators: 38.46M gas (128% of 30M block limit) ❌
• 100 history entries (with 100 operators): 52.58M gas (175% of block limit) ❌
• 250 operators + 50 history: 82.99M gas (276% of block limit) ❌

Growth Rates:

• Operator count has super-linear growth: 2x operators = 2.09x gas
• History length has super-linear growth: 2x history = 1.58x gas

Safe Operating Thresholds:

• Maximum ~400 operators with minimal history
• Maximum ~80 history entries with 100 operators

Recommendations

1. Immediate: Implement gas limit checks and circuit breakers
2. Long-term: Consider multi-step updates, history trimming, or pagination

Test Results

All gas tests pass and provide clear metrics:

✓ testGasUsageWithVaryingOperatorCounts
✓ testGasUsageWithVaryingHistoryLengths  
✓ testGasGrowthRate
✓ testWorstCaseScenario

Related Issues

Fixes #1

🤖 Generated with Claude Code