ethersjs

• ethers-io/ethers.js
  • MIT, TS
  • 内置 ether.util.BigNumber - 封装 BN.js
    • elliptic 使用的 BN.js - 因为必须包含 elliptic 所以使用 BN.js 不需要引入额外包
    • BN.js 与 ether 计算逻辑相同，底层为纯 int + decimals，两个数值计算要考虑 decimals
    • bignumber.js 底层存储了 c,e,s 辅助计算，两个数值可直接计算
    • 个人使用推荐 bignumber.js - 接口更友好
• 参考
  • https://docs.ethers.io/v5/
  • Why not BigNumber.js, BN.js, BigDecimal, etc?
  • ethers.js: Human-Readable Contract ABIs

Unit	Decimals
wei	0
kwei	3
mwei	6
gwei	9
szabo	12
finney	15
ether	18

// MetaMask
const provider = new ethers.providers.Web3Provider(window.ethereum);
const signer = provider.getSigner();

// Web3Provider({request,sendAsync,send})
// WebSocketProvider
// StaticJsonRpcProvider - 避免 chainId 修改的影响
// EtherscanProvider - homestead, ropsten, rinkeby, goerli, kovan
// InfuraProvider
// AlchemyProvider
// CloudflareProvider - homestead
// PocketProvider
// AnkrProvider - homestead, matic, arbitrum
// FallbackProvider - 支持多个 Provider
// IpcProvider
const provider = new ethers.providers.JsonRpcProvider('http://localhost:8545', {chainId: '1337', name: 'dev'});

let ecr20 = [
  `function name() view returns (string)`,
  `function symbol() view returns (string)`,
  `function decimals() view returns (uint8)`,
  `function totalSupply() view returns (uint256)`,
  'function balanceOf(address owner) view returns (uint)',
  'function transfer(address to, uint256 value) returns (bool success)',
  'function transferFrom(address from, address to, uint256 value) returns (bool success)',
  'function approve(address spender, uint256 value) returns (bool success)',
  'function allowance(address owner, address spender)  view returns (uint256 remaining)',

  'event Transfer(address indexed from, address indexed to, uint256 _value)',
  'event Approval(address indexed owner, address indexed spender, uint256 _value)',
];
let ecr165 = ['function supportsInterface(interfaceId bytes4) view returns (bool)'];
let ecr1820registry = [
  'function getInterfaceImplementer(address addr, bytes32 interfaceHash) view returns (address)',
  'function setInterfaceImplementer(address addr, bytes32 interfaceHash, address implementer)',
  'function setManager(address addr, address newManager)',
  'function getManager(address addr) view returns(address)',
  'function interfaceHash(string calldata interfaceName) pure returns(bytes32)',
];
let ecr1820implementer = [
  'function canImplementInterfaceForAddress(bytes32 interfaceHash, address addr) view returns(bytes32)',
];

// ropsten usdc
let contract = new ethers.Contract('0x07865c6E87B9F70255377e024ace6630C1Eaa37F', [...ecr20, ...ecr165], signer);

// 0x01ffc9a7 - 4bytes
let interfaceId = ethers.utils.keccak256(ethers.utils.toUtf8Bytes('supportsInterface(bytes4)')).substring(0, 10);
let interfaceId = ethers.utils.id('supportsInterface(bytes4)');
contract.supportsInterface(interfaceId);

new ethers.utils.Interface(ecr165).format(ethers.utils.FormatTypes.minimal);
// balanceOf
ethers.utils.formatUnits(await contract.balanceOf(await signer.getAddress()), await contract.decimals());

// abi - json,human readable
let iface =  new ethers.utils.Interface(abi);
iface.format(ethers.utils.FormatTypes.full);
iface.format(ethers.utils.FormatTypes.minimal);
iface.format(ethers.utils.FormatTypes.json);

ethers.utils.formatEther(value)
// 默认 ether
ethers.utils.formatUnits(value, "ether").

interface ECR20 {
  name(): Promise<string>;

  symbol(): Promise<string>;

  decimals(): Promise<number>;

  balanceOf(address: string): Promise<ethers.BigNumber>;
}

interface ECR165 {
  supportsInterface(interfaceId: any);
}

events

• https://docs.ethers.io/v5/concepts/events/

FAQ

requested too many blocks from 0 to 11846057, maximum is set to 2048

API Provider 限制了

• avax testnet 2048