web3js的一个Typescript移植

# web3x [](https://www.npmjs.com/package/web3x) [](https://www.npmjs.com/package/web3x) [](https://www.npmjs.com/package/web3x-es) [](https://github.com/xf00f/web3x) [](https://github.com/xf00f/web3x/stargazers) [](https://github.com/xf00f/web3x/issues) [](https://coveralls.io/github/xf00f/web3x) [](https://github.com/xf00f/web3x/blob/master/LICENSE) TypeScript port of web3.js - for perfect types and tiny builds.  ## Table of contents - [Why?](#why) - [Usage](#usage) - [Contract type safety](#contract-type-safety) - [Differences](#differences) - [Example projects](#example-projects) - [Documentation](#documentation) - [Packages](#packages) ## Why? web3.js is a very popular Ethereum library, but: - It has inaccurate typings and there's no way to to introduce type safety to contract code. - It's large, weighing in at ~800k uncompressed. web3x solves the above issues. - It's pure TypeScript and generates contract types from ABIs. - It's small, with a minimum sized contract interaction weighing in at ~150k uncompressed. ## Usage There are two builds of the library. `web3x` uses CommonJS style imports and is best used for Node.js backends. `web3x-es` uses ES6 imports and is best used for ES6 aware tools like Webpack. Example usage: ```typescript import { WebsocketProvider } from 'web3x-es/providers'; import { Eth } from 'web3x-es/eth'; import { fromWei } from 'web3x-es/utils'; async function main() { const provider = new WebsocketProvider('wss://mainnet.infura.io/ws'); const eth = Eth.fromProvider(provider); const balance = await eth.getBalance('0x0000000000000000000000000000000000000000'); document.body.innerText = `Balance of 0 address ETH: ${fromWei(balance, 'ether')}`; } main().catch(console.error); ``` See example projects for more complex examples. ## Contract type safety Interacting with contracts without type safety is tedious at best, and dangerous at worst. web3x provides a code generator called `web3x-codegen` to generate typings for contract ABIs either local, or remote from a simple configuration file called `contracts.json`. ### Defining contracts.json An example `contracts.json` looks like: ```json { "outputPath": "./src/contracts", "contracts": { "DaiContract": "http://api.etherscan.io/api?module=contract&action=getabi&address=0x89d24a6b4ccb1b6faa2625fe562bdd9a23260359&format=raw", "MyContract": "../truffle-project/build/contracts/MyContract.json" } } ``` Run the code generator: ``` yarn web3x-codegen ``` The generator downloads the ABI for the DAI token from the given location on etherscan, and generates the interface at `./src/contracts/DaiContract.ts`. It also specifies a local ABI file and generates its interface at `./src/contracts/MyContract.ts`. The json files output by truffle are not pure ABIs, but the code generator will detect it's a truffle output and will extract the ABI accordingly. For an example of the code generated, take a look at this [example](example-projects/node/src/contracts/DaiContract.ts). ### Using generated contracts The following code demonstrates how to use the generated contract class. It's the exact same API as used in web3.js, only now with typesafety. ```typescript import { fromWei } from 'web3x/utils'; import { WebsocketProvider } from 'web3x/providers'; import { Eth } from 'web3x/eth'; import { DaiContract } from './contracts/DaiContract'; const ZERO_ADDRESS = '0x0000000000000000000000000000000000000000'; const DAI_CONTRACT_ADDRESS = '0x89d24a6b4ccb1b6faa2625fe562bdd9a23260359'; async function main() { const provider = new WebsocketProvider('wss://mainnet.infura.io/ws'); const eth = Eth.fromProvider(provider); try { const contract = new DaiContract(eth, DAI_CONTRACT_ADDRESS); const daiBalance = await contract.methods.balanceOf(ZERO_ADDRESS).call(); console.log(`Balance of 0 address DAI: ${fromWei(daiBalance, 'ether')}`); } finally { provider.disconnect(); } } main().catch(console.error); ``` ## Differences This is not a perfect drop in replacement for web3.js, there are small differences. - Callbacks for request/response style calls no longer supported, promises only. - You should explicitly import parts of the library rather then accessing them via the web3 object. - Sanitized some hybrid types, e.g. access wallet accounts via `wallet.get(0)` rather than `wallet[0]`. ## Example projects Two example TypeScript projects are included, one for [webpack](example-projects/webpack) and one for [node.js](example-projects/node). They are configured to work with jest for testing. Adapting them to pure JavaScript if you don't want to use TypeScript should be trivial. ## Documentation API documentation has not yet been ported from web3.js. For now the recommended approach for familiarising yourself with the library would be the following, in preferential order: - Read the web3.js documentation at https://web3js.readthedocs.io/en/1.0/ to familiarise yourself with its API. - Take a look at the example projects such as the [webpack example](example-projects/webpack/src/index.ts). - Rely on your IDE and TypeScript to provide insight into the API. - Delve into the code. It's significantly easier to follow and understand than web3.js. ## Packages - [web3x](https://www.npmjs.com/package/web3x) (for Node.js) - [web3x-es](https://www.npmjs.com/package/web3x-es) (for ES6 aware tools such as Webpack)