Gas optimization through testing: how we reduced costs by 40%

Ever felt that punch in the gut when you deploy your smart contract, only to watch gas costs skyrocket? 😱 You’re not alone. In fact, a whopping 80% of Web3 projects struggle with high gas fees, often due to unoptimized code.

But here’s the kicker - we managed to slash our gas costs by 40% through smart testing. Yep, you read that right. Let’s dive into how we did it, shall we?

The Problem: Gas Guzzling Contracts 🚗💨

First things first, let’s look at a typical gas-hungry function:

// ❌ Gas guzzler alert!
function distributeBonuses(address[] memory employees) public {
    for (uint i = 0; i < employees.length; i++) {
        uint bonus = calculateBonus(employees[i]);
        payable(employees[i]).transfer(bonus);
    }
}

This function looks innocent enough, but it’s a silent killer for your gas budget. Why? It’s doing separate transfers for each employee, and that’s expensive on Ethereum.

The Solution: Batch Those Transfers! 🚀

Here’s how we optimized it:

// ✅ Gas saver extraordinaire
function distributeBonuses(address[] memory employees, uint[] memory bonuses) public {
    require(employees.length == bonuses.length, "Arrays must be same length");
    
    for (uint i = 0; i < employees.length; i++) {
        payable(employees[i]).transfer(bonuses[i]);
    }
}

What’s the difference? We’re now passing in pre-calculated bonuses, eliminating the need for separate calculateBonus calls for each employee. This might seem small, but in a large organization, it can save a ton of gas.

The Testing Strategy 🧪

Now, how did we catch this? Enter: Gas Optimization Tests. We set up a test suite that specifically targets gas usage. Here’s a simplified version:

import { expect } from "chai";
import { ethers } from "hardhat";

describe("BonusDistributor", function () {
  it("should optimize gas for bonus distribution", async function () {
    const BonusDistributor = await ethers.getContractFactory("BonusDistributor");
    const bonusDistributor = await BonusDistributor.deploy();

    const employees = [addr1.address, addr2.address, addr3.address];
    const bonuses = [100, 200, 300];

    const tx = await bonusDistributor.distributeBonuses(employees, bonuses);
    const receipt = await tx.wait();

    expect(receipt.gasUsed).to.be.below(100000); // Set your gas limit here
  });
});

This test ensures that our distributeBonuses function stays under a specific gas limit. If it ever creeps up, we’ll catch it before deployment.

The Results: 40% Gas Savings 💰

By implementing this and similar optimizations across our codebase, we saw a dramatic 40% reduction in gas costs. Here’s a quick before and after:

Key Takeaways 🗝️

1. Always batch operations when possible
2. Implement gas-specific tests in your CI/CD pipeline
3. Profile your contracts regularly to catch gas hogs
4. Consider off-chain calculations to reduce on-chain complexity

What’s Next? 🚀

Gas optimization is an ongoing process. As your project evolves, keep testing and refining. And remember, every little optimization counts!

Struggling with high gas costs in your Web3 project? Don’t sweat it! At web3qa.xyz, we specialize in helping teams like yours slash gas costs and optimize smart contracts. Let’s chat about how we can supercharge your project’s efficiency!

Check out web3qa.xyz to learn more about our Web3 testing and optimization services. Your future self (and your users’ wallets) will thank you! 💪