decode

Inputs a Bitcoin transaction or a transaction id and returns its metadata if it is a Bitcoin Computer transaction.

Type

;(tx: NakamotoJS.Transaction | string) =>
  Promise<{
    exp: string
    env?: { [s: string]: string }
    mod?: string
  }>

Parameters

`tx`

A NakamotoJS transaction, or a string representing a transaction ID.

Return Value

An object containing the following properties:

Parameter	Description
exp	The JavaScript expression of the transaction
env	A mapping from variable names to revisions
mod	A module specifier

Description

The decode function takes a Bitcoin transaction or a transaction ID as input and retrieves the associated metadata if the transaction is a Bitcoin Computer transaction. This metadata includes the JavaScript expression, any environment variables, and an optional module specifier.

Example

import { Computer, Contract } from '@bitcoin-computer/lib'
import { chain, expect, network, url } from '../../utils/index.js'

describe('decode', () => {
  it('Should decode a transaction', async () => {
    // A smart contract
    class C extends Contract {}

    // Create and fund a wallet
    const computer = new Computer({ chain, network, url })
    await computer.faucet(1e8)

    // A transition encodes an update to the on-chain state
    const transition = {
      exp: `${C} new C()`,
      env: {},
      mod: undefined,
    }

    // Encode the transition to a transaction
    const { tx } = await computer.encode(transition)

    // Decode transaction back into transition
    const decoded = await computer.decode(tx!)
    expect(decoded).to.deep.equal(transition)
  })

  it('Should decode a txId', async () => {
    // A smart contract
    class C extends Contract {}

    // Create and fund a wallet
    const computer = new Computer({ chain, network, url })
    await computer.faucet(1e8)

    // A transition encodes an update to the on-chain state
    const transition = {
      exp: `${C} new C()`,
      env: {},
      mod: undefined,
    }

    // Encode the transition to a transaction
    const { tx } = await computer.encode(transition)
    await computer.broadcast(tx!)

    // Decode transaction back into transition
    const decoded = await computer.decode(tx!.getId())
    expect(decoded).to.deep.equal(transition)
  })
})

Source