https://jeiwan.net/tags/solidity/ Recent content in Solidity on Going the distance Hugo -- gohugo.io en Sun, 24 Apr 2022 00:00:00 +0000 https://jeiwan.net/posts/programming-defi-uniswapv2-4/ Sun, 24 Apr 2022 00:00:00 +0000 https://jeiwan.net/posts/programming-defi-uniswapv2-4/ Photo by British Library on Unsplash Introduction Welcome to the final part of this series! Yes, we’ve almost done implementing a Uniswap V2 clone from scratch, and today we’re going to fill missing gaps. There’s a lot of things to do, so let’s get straight to business. You can find full source code of this part here: source code, part 4. LP-tokens burning bug We’ll begin with finishing the Router contract. https://jeiwan.net/posts/evaluating-defi-strategy-in-foundry/ Mon, 11 Apr 2022 00:00:00 +0000 https://jeiwan.net/posts/evaluating-defi-strategy-in-foundry/ Photo by Brett Jordan on Unsplash Introduction Nowadays, the ecosystem of Ethereum is quite rich and complex. There are multitudes of DeFi applications: decentralized exchanges, staking protocols, money markets, yield farming vaults, derivatives, leverages, etc. As DeFi protocol evolve, they become more and more intertwined, allowing for new complex strategies. In this article, I’ll show you how to program a custom DeFi strategy that interacts with several DeFi platforms to produce a leveraged position that earns passive income. https://jeiwan.net/posts/programming-defi-uniswapv2-3/ Tue, 15 Mar 2022 00:00:00 +0000 https://jeiwan.net/posts/programming-defi-uniswapv2-3/ Photo by C Dustin on Unsplash Introduction Another month, another blog post! 🙈 So far, our UniswapV2 implementation had the most crucial part done–the pair contract. We haven’t yet implemented protocol fees (the fee Uniswap takes from each liquidity deposit) but we’ll do this a little bit later since this is not a critical part of the exchange. Today, we’ll move forward and implement the factory contract, which serves as a registry of all deployed pair contracts. https://jeiwan.net/posts/programming-defi-uniswapv2-2/ Mon, 31 Jan 2022 00:00:00 +0000 https://jeiwan.net/posts/programming-defi-uniswapv2-2/ Photo by Jon Cellier on Unsplash Introduction Welcome back! Today we’ll add the core functionality to our clone of Uniswap V2–swapping. Decentralized tokens exchanging is what Uniswap was created for, and today we’ll see how it’s done. We’re still working on the core pair contract, which means that our implementation will be very low-level and minimal. There’s no convenient interface and we won’t even have price calculation at this point! https://jeiwan.net/posts/programming-defi-uniswapv2-1/ Tue, 11 Jan 2022 00:00:00 +0000 https://jeiwan.net/posts/programming-defi-uniswapv2-1/ Photo by Evangelos Mpikakis on Unsplash Introduction Uniswap is a decentralized exchange running on the Ethereum blockchain. It’s fully automated, not managed, and decentralized. It has come through multiple iterations of development: first version was launched in November 2018; second version–in May 2020; and final, third, version was launched in March 2021. In my previous series on Uniswap V1, I showed how to build it from scratch and explained its core mechanics. https://jeiwan.net/posts/ethernaut-tips-and-solutions/ Thu, 02 Dec 2021 00:00:00 +0000 https://jeiwan.net/posts/ethernaut-tips-and-solutions/ Photo by Jukan Tateisi on Unsplash Introduction Ethernaut is an (awesome) browser game that let’s you practice Web3 and Solidity whilte solving different tasks. The game consists of 23 levels (as of August 2021) and each level is focused on some Solidity feature or bug, smart contract design flaw, or unexpected behaviour of a contract. Your goals in each level is to hack it: to find a way of becoming a contract owner, to transfer all tokens to your own address, or abuse a feature of Solidity that wasn’t taken into consideration by a smart contract developer. https://jeiwan.net/posts/upgradeable-proxy-from-scratch/ Wed, 25 Aug 2021 00:00:00 +0000 https://jeiwan.net/posts/upgradeable-proxy-from-scratch/ Photo by Rafał Naczyński on Unsplash Immutability gives Ethereum a big benefit: once a smart contract is deployed, there’s no way to change it. This means that smart contract logic won’t change over time and it’ll remain as reliable as it was from the beginning, e.g. you won’t suddenly see a contract doing something no one thought it could do. However, immutability comes with drawbacks that can be significant in some cases.