🛡️ Efficient Error Handling: Gas Benchmarking & Patterns

A comparative research implementation analyzing the gas impact of different error handling strategies in Solidity. This project quantifies the trade-offs between legacy string-based validation and modern Custom Errors.

In the EVM, every byte of text stored in the contract bytecode increases deployment costs, and emitting those strings at runtime triggers memory expansion. This repository demonstrates how moving to 4-byte error selectors significantly reduces on-chain footprint.

🏗 Architecture & Design Decisions

1. Gas Optimization (Bytecode vs. Selector)

• Legacy Pattern (require strings):
  • Mechanism: Stores full ASCII strings in the bytecode. At runtime, it requires memory allocation (MSTORE) to encode the error message.
  • Cost: High deployment cost (bytecode size) and higher runtime gas due to dynamic memory expansion.
• Modern Pattern (Custom Errors):
  • Mechanism: Utilizes Solidity 0.8.4+ specific error Name().
  • Optimization: Returns a fixed 4-byte selector (hash of the error signature). This avoids memory expansion for string encoding and allows dynamic parameters to be passed efficiently via the stack.

2. Architectural Trade-offs

• Raw Reverts (if + revert()):
  • Implemented for benchmarking the "absolute floor" of gas usage. While cheapest, it is architecturally discouraged for production systems due to the lack of debugging context (DX).
• Semantic Validation:
  • The RequireTest contract demonstrates that revert CallerIsNotAdmin(msg.sender) provides superior observability compared to generic strings, allowing off-chain indexers to decode the exact failure reason and context parameters programmatically.

🛠 Tech Stack

• Core: Solidity ^0.8.24
• Features: Custom Errors (EIP-838), ABI Encoding
• Focus: Gas Profiling & Opcode Analysis

📝 Code Comparison

The benchmark isolates three distinct patterns for the same logical check:

// 1. Expensive (String stored in bytecode)
require(msg.sender == admin, "Caller must be admin");

// 2. Optimized (4-byte selector)
if (msg.sender != admin) {
    revert CallerIsNotAdmin(msg.sender);
}

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Reference implementation for EVM gas optimization strategies.