core-blockchain-helper

Blockchain utilities for EVM-style chains: addresses (EIP-55), hex/bytes, wei/ether units, chain IDs, and encoding helpers.

Install

npm install core-blockchain-helper

Usage

const {
  getAddress,
  isAddress,
  toChecksumAddress,
  shortenAddress,
  formatEther,
  parseEther,
  weiToGwei,
  getChainName,
  isHex,
  hexToBytes,
  toBytes32,
  concatHex,
} = require('core-blockchain-helper');

// Address (EIP-55 checksum)
getAddress('0xfb6916095ca1df60bb79ce92ce3ea74c37c5d359');
// => '0xfB6916095ca1df60bB79Ce92cE3Ea74c37c5d359'
isAddress('0x1234...');           // false
shortenAddress(addr);            // '0xfB69...d359'

// Units
formatEther(1000000000000000000n);  // '1'
parseEther('1.5');                  // 1500000000000000000n
weiToGwei(1000000000n);             // 1

// Chains
getChainName(1);    // 'Ethereum Mainnet'
getChainName(137);  // 'Polygon'

// Hex
isHex('0xdead');    // true
hexToBytes('0x0102'); // Uint8Array [1, 2]
toBytes32(255);     // '0x...' 32-byte hex
concatHex('0x01', '0x02'); // '0x0102'

Subpath imports

const { getAddress, toChecksumAddress } = require('core-blockchain-helper/address');
const { formatEther, parseEther } = require('core-blockchain-helper/units');
const { getChainName, CHAINS } = require('core-blockchain-helper/chains');
const { isHex, hexToBytes, bytesToHex } = require('core-blockchain-helper/hex');
const { toBytes32, leftPadHex } = require('core-blockchain-helper/encoding');

API

Address (lib/address.js)

| Method | Description | |--------|-------------| | isAddress(value) | Valid 20-byte hex address | | toChecksumAddress(address) | EIP-55 mixed-case checksum | | verifyChecksum(address) | True if address matches its checksum | | getAddress(address) | Checksummed address or throws | | isZeroAddress(address) | All zeros | | shortenAddress(address, chars?) | 0x1234...5678 |

Hex (lib/hex.js)

| Method | Description | |--------|-------------| | stripHex(value) | Remove 0x prefix | | ensureHex(value) | Ensure 0x prefix | | isHex(value, options?) | Valid hex string | | hexToBytes(hex) | Hex → Uint8Array | | bytesToHex(bytes) | Bytes → 0x hex | | hexToBigInt(hex) | Hex → BigInt | | bigIntToHex(value) | BigInt → hex | | hexToUtf8(hex) | Hex → UTF-8 string | | utf8ToHex(str) | UTF-8 string → hex | | isTxHash(value) | Valid tx hash (0x + 64 hex) | | shortenTxHash(txHash, chars?) | 0x1234...abcd |

Units (lib/units.js)

| Method | Description | |--------|-------------| | formatEther(wei) | Wei → decimal string (18 decimals) | | formatUnits(wei, decimals) | Wei → decimal string | | parseEther(ether) | Ether string → wei (BigInt) | | parseUnits(value, decimals) | Decimal string → wei (BigInt) | | weiToEther / etherToWei | Number conversion | | weiToGwei / gweiToWei | Gwei conversion |

Chains (lib/chains.js)

| Method | Description | |--------|-------------| | CHAINS | Object of chainId → name | | getChainName(chainId) | Human-readable network name | | isMainnet(chainId) | chainId === 1 | | isTestnet(chainId) | Known testnet |

Encoding (lib/encoding.js)

| Method | Description | |--------|-------------| | leftPadHex(hex, length?) | Pad to 32 bytes (default) | | rightPadHex(hex, length?) | Right-pad to length | | toBytes32(value) | Number/BigInt/hex → 32-byte hex | | fromBytes32(hex) | 32-byte hex → BigInt | | concatHex(...hexStrings) | Concatenate hex strings |

Dependencies

• js-sha3 – Keccak-256 for EIP-55 checksum

License

MIT