# Jesper Jesper is a simple, yet powerful, error generator for Solidity. It allows you to generate typescript errors from your Solidity code, and use them to create custom error messages. ## Installation ```bash npm install jasper ``` ## Usage Jesper automatically parses the output folder of your framework and generates a typescript file with all the errors in it. You can then import this file and use it to create custom error messages. You can also optionally leave a message on top of the error which will add a custom message to the error. The error arguments can also be injected into the message by using the `{}` syntax. Rules - The error message must be on the same line as the error declaration - The error message must start with `//#Message:` - The error message must be on the same line as the error declaration - The injected arguments must be wrapped in `{}` - The error must be wrapped in quotes "" ```typescript contract MyContract { error ErrIsContract(); //#Message: "USDG: NotVetoCouncilMember" error ErrNotVetoCouncilMember(); //#Message: "USDG: PermanentlyFrozen" error ErrPermanentlyFrozen(); //#Message: "USDG: ToCannotBeUSDCReceiver" error ToCannotBeUSDCReceiver(); //#Message: "USDG: CannotSwapZero" error ErrCannotSwapZero(); //#Message: "Cannot send to {user}" error ErrCannotSendToUser(address user, address sender); //......rest of logic } ``` ## Commands ### Init project This creates a default `jesper-config.json` file in the root of your project. `jesper init` ### Generate errors `jesper gen` ## Config ```typescript { "outputFolder": "./jesper-bindings", // The folder where the generated typescript file will be placed "typescript": true, //does nothing for now, will get JS bindings soon "framework": "foundry", //foundry | hardhat "contractsPath": "./contracts", //The path where the contracts are located "excludedFiles": ["./contracts/Migrations.sol"], //Files to exclude, doesen't work yet "extraIncludedFiles": [], //Extra files to include, doesen't work yet "modes": ["Viem"] //Viem | EthersV5 } ``` ## About The Output Jesper will output a typescript file with all the errors in it. The file will be named `jesper-bindings.ts` and will be placed in the `outputFolder` specified in the config. Another file will be generated based on the `modes` specified in the config. This file will be named `jesperParseError.ts` and will be placed in the `outputFolder` specified in the config as well. It exports a function called `jesperParseError` which takes in error data and returns a string. This function is used to parse the error message and inject the arguments into the message. ## Roadmap - [x] Make sure you can't inject an error argument that doesen't exist. - [x] Setup tests - [x] Setup CI - [x] More stuff I can't think of, just did a 12h bender on this ## Author Made by 0xSimon