hardhat-storage-layout-changes

Hardhat plugin to check for storage layout changes

What

When working with complex and upgradable contracts, it can be difficult to manually see whether some solidity changes broke the storage layout or not. A mistake can cause undefined behavior in deployed contracts. This plugin aims to help notice any storage layout breakings while dev works on solidity changes.

Installation

npm install hardhat-storage-layout-changes

Import the plugin in your hardhat.config.js:

require("hardhat-storage-layout-changes");

Or if you are using TypeScript, in your hardhat.config.ts:

import "hardhat-storage-layout-changes";

Tasks

This plugin adds the storage-layout task to Hardhat:

Usage: hardhat [GLOBAL OPTIONS] storage-layout [--check] [--update]

OPTIONS:

  --check       Checks if storage layout has changed
  --update      Updates storage layout artifact

Configuration

This plugin extends the HardhatUserConfig's ProjectPathsUserConfig object with an optional storageLayouts field and also adds a storageLayoutConfig.

This is an example of how to set it:

module.exports = {
  paths: {
    storageLayouts: ".storage-layouts",
  },
  storageLayoutConfig: {
    contracts: ["Pool"],
    fullPath: false
  };
};

Usage

npx hardhat storage-layout --check

Contract: Pool
   "accounts": at same location
         "user": at same location
         "balance": at same location
   "owner": changed slot from 1 to 2
   "lastUpdate": found new storage entry at slot 1 offset 0
   "owner": found new storage entry at slot 2 offset 0

Error: Storage Layout Changed. If this was intentional, please update the storage layout files using "npx hardhat storage-layout --update".

npx hardhat storage-layout --update

Contract: Pool
updating Pool.json