Solidity Type Conversion Utils

NOTE: this repo is super early in development and no where near production-ready. Please use under careful discretion.

Motivation

Conversion between types in Solidity can be tricky. Sometimes explicit typecasting would do the work, while it won't in other occasions (e.g. addressToString, i.e. hexstring to UTF-8).

If you are looking for utility library for bytes and string operations, look no further than Goncalo's bytes-utils and Nick Johnson's stringutils.

This library is mainly for conversion between types, especially between uint, bytes and string, fixed or dyanmic, we would like to abstract away those details and provide clean, intuitive API for Solidity dev.

Installation

npm install solidity-conv

TODO: publish under EthPM when more ready.

Usage

in your Solidity contract, import it using:

import "solidity-conv/contracts/(whichever).sol";

make sure your solc version is update to date, (currently the library uses ^0.5.5) otherwise compilation errors occur. My personal recommendation is specify this in your truffle-config.json (or whatever name you give to your truffle config)

module.exports = {
  compilers: {
    solc: {
      version: "0.5.5",
    },
  }
}

Examples

pragma solidity ^0.5.5;

import "solidity-conv/contracts/LibBytesString.sol";

contract myContract is LibBytesString {
  function myFunc() public pure returns (string memory) {
    address dai = 0x89d24A6b4CcB1B6fAA2625fE562bDD9a23260359;
    // ERROR: Explicit type conversion not allowed (from fixed to dyanmic)
    // string memory greet = string(dai);
    
    // CORRECT: this how you rock:
    string memory greet = addressToString(dai);
    return greet;
  }
}

Contributing

All contributions are welcomed.

Roadmap:

addressToString PoC with tests
extending to bytesToString, stringToBytes, uintToBytes, etc.
consider exposing better API
inline assembly optimization

alxiong / solidity-conv