eip-712/src/utils/buffer.test.ts

Tiny library with utility functions that can help with signing and verifying EIP-712 based messages

import { bytesToHex } from '@noble/hashes/utils';
import { keccak256, toBuffer } from './buffer';

describe('keccak256', () => {
  it('returns a keccak256 hash of a string', () => {
    expect(bytesToHex(keccak256('foo bar'))).toBe('737fe0cb366697912e27136f93dfb531c58bab1b09c40842d999110387c86b54');
    expect(bytesToHex(keccak256('foo bar', 'utf8'))).toBe(
      '737fe0cb366697912e27136f93dfb531c58bab1b09c40842d999110387c86b54'
    );
  });

  it('returns a keccak256 hash of a buffer', () => {
    const buffer = Buffer.from('foo bar', 'utf8');
    expect(bytesToHex(keccak256(buffer))).toBe('737fe0cb366697912e27136f93dfb531c58bab1b09c40842d999110387c86b54');
  });
});

describe('toBuffer', () => {
  it('returns a buffer for a string', () => {
    expect(new TextDecoder().decode(toBuffer('666f6f20626172'))).toBe('foo bar');
    expect(new TextDecoder().decode(toBuffer('foo bar', 'utf8'))).toBe('foo bar');
  });

  it('works with a 0x prefix', () => {
    expect(new TextDecoder().decode(toBuffer('0x666f6f20626172'))).toBe('foo bar');
  });
});