--- title: Modifying EVM Storage to Seed Token Balances in Testing description: This post explores the concept of modifying EVM storage directly with a seeding function in order to simplify testing of smart contracts. It explains how EVM... canonical: https://daily.dev/posts/modifying-evm-storage-to-seed-token-balances-in-testing-pdknsa2zv twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Modifying EVM Storage to Seed Token Balances in Testing | daily.dev og:description: This post explores the concept of modifying EVM storage directly with a seeding function in order to simplify testing of smart contracts. It explains how EVM... og:url: https://daily.dev/posts/modifying-evm-storage-to-seed-token-balances-in-testing-pdknsa2zv og:image: https://api.daily.dev/og/posts/PdknSa2Zv.png og:image:alt: Modifying EVM Storage to Seed Token Balances in Testing og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Modifying EVM Storage to Seed Token Balances in Testing **[Coins Bench](https://daily.dev/sources/coinsbench)** · 8 min read · 0 upvotes · 0 comments ## Summary This post explores the concept of modifying EVM storage directly with a seeding function in order to simplify testing of smart contracts. It explains how EVM storage works, provides code examples, and demonstrates how to use Hardhat.js to manipulate the local EVM storage. The article also discusses nested mappings and offers a helper function for directly modifying storage. Overall, it offers insights into improving testing processes for smart contracts. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: --- Tags: [#testing](https://daily.dev/tags/testing), [#crypto](https://daily.dev/tags/crypto), [#blockchain](https://daily.dev/tags/blockchain), [#ethereum](https://daily.dev/tags/ethereum), [#smart-contracts](https://daily.dev/tags/smart-contracts), [#solidity](https://daily.dev/tags/solidity), [#hardhat](https://daily.dev/tags/hardhat) [View this post on daily.dev](https://daily.dev/posts/modifying-evm-storage-to-seed-token-balances-in-testing-pdknsa2zv) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Modifying EVM Storage to Seed Token Balances in Testing","url":"https://daily.dev/posts/modifying-evm-storage-to-seed-token-balances-in-testing-pdknsa2zv","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/modifying-evm-storage-to-seed-token-balances-in-testing-pdknsa2zv"},"datePublished":"2024-02-16T15:58:46.907Z","dateModified":"2024-05-09T09:28:18.744Z","description":"This post explores the concept of modifying EVM storage directly with a seeding function in order to simplify testing of smart contracts. 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