Gas benchmark for DiamondLoupeContract

[lumoswiz]

Summary

To aid evaluation of #155.

Adds a reusable gas benchmark harness for Diamond Loupe. It spins up a minimal diamond, plugs in a user-provided loupe facet, and synthetically builds a large diamond in storage (default: 200 facets × 10 selectors) so anyone can drop in an optimised loupe and immediately measure gas for the four view functions.

Changes Made

To tests/benchmark, added:

• MinimalDiamond.sol: adapted from a reference implementation.
• Base.t.sol: abstract test harness that deploys MinimalDiamond setup with four loupe selectors, and builds complex storage for the diamond.
• Utils.sol: storage helpers, constants and builder functions.
• Benchmark.t.sol: baseline gas tests against current DiamondLoupeFacet.
• Optimised.t.sol: same tests as the benchmark, but _deployLoupe should be overriden with the optimised contract.

Checklist

Before submitting this PR, please ensure:

• Code follows the Solidity feature ban - No inheritance, constructors, modifiers, public/private variables, external library functions, using for directives, or selfdestruct

• Code follows Design Principles - Readable, uses diamond storage, favors composition over inheritance

• Code matches the codebase style - Consistent formatting, documentation, and patterns (e.g. ERC20Facet.sol)

• Code is formatted with forge fmt

• Tests are included - All new functionality has comprehensive tests

• All tests pass - Run forge test and ensure everything works

• Documentation updated - If applicable, update relevant documentation

Make sure to follow the CONTRIBUTING.md guidelines.

Additional Notes

Run benchmarks with:
forge test --mt LoupeGasBenchmarkTest -vv
forge test --mt OptimisedLoupeBenchmarkTest -vv

[github-actions]

Coverage Report

Metric	Coverage	Details
Lines	49%	667/1370 lines
Functions	62%	143/232 functions
Branches	25%	63/249 branches

Last updated: Sun, 02 Nov 2025 22:06:38 GMT for commit 1161789

[github-actions]

Gas Report

No gas usage changes detected between main and bench/diamond-gas-200facets.

All functions maintain the same gas costs. ✅

Last updated: Sun, 02 Nov 2025 22:06:53 GMT for commit 1161789

[mudgen]

Thanks, I am going to try this out! The formatting check forge -fmt --check failed, but I will fix that.

[mudgen]

I tried it out, it works!