bitcoinjs-lib/test/integration/blocks.spec.ts

import * as assert from 'assert';
import { describe, it } from 'mocha';
import * as bitcoin from '../..';

describe('bitcoinjs-lib (blocks)', () => {
  it('can extract a height from a CoinBase transaction', () => {
    // from 00000000000000000097669cdca131f24d40c4cc7d80eaa65967a2d09acf6ce6
    const txHex =
      '010000000001010000000000000000000000000000000000000000000000000000000' +
      '000000000ffffffff50037f9a07174d696e656420627920416e74506f6f6c685b205a' +
      '2b1f7bfabe6d6d36afe1910eca9405b66f97750940a656e38e2c0312958190ff8e98f' +
      'd16761d220400000000000000aa340000d49f0000ffffffff02b07fc3660000000019' +
      '76a9148349212dc27ce3ab4c5b29b85c4dec643d764b1788ac0000000000000000266' +
      'a24aa21a9ed72d9432948505e3d3062f1307a3f027a5dea846ff85e47159680919c12' +
      'bf1e40012000000000000000000000000000000000000000000000000000000000000' +
      '0000000000000';
    const tx = bitcoin.Transaction.fromHex(txHex);

    assert.strictEqual(tx.ins.length, 1);
    const script = tx.ins[0].script;
    // bitcoin.script.decompile(script) // returns [] :(

    assert.strictEqual(script[0], 0x03);
    const heightBuffer = script.slice(1, 4);
    const height = bitcoin.script.number.decode(heightBuffer);
    assert.strictEqual(height, 498303);
  });
});