const { describe, it, beforeEach } = require('mocha')
const assert = require('assert')
const baddress = require('../src/address')
const bscript = require('../src/script')
const payments = require('../src/payments')

const ECPair = require('../src/ecpair')
const Transaction = require('..').Transaction
const TransactionBuilder = require('..').TransactionBuilder
const NETWORKS = require('../src/networks')

const fixtures = require('./fixtures/transaction_builder')

function constructSign (f, txb) {
  const network = NETWORKS[f.network]
  const stages = f.stages && f.stages.concat()

  f.inputs.forEach((input, index) => {
    if (!input.signs) return
    input.signs.forEach(sign => {
      const keyPair = ECPair.fromWIF(sign.keyPair, network)
      let redeemScript
      let witnessScript
      let value

      if (sign.redeemScript) {
        redeemScript = bscript.fromASM(sign.redeemScript)
      }

      if (sign.value) {
        value = sign.value
      }

      if (sign.witnessScript) {
        witnessScript = bscript.fromASM(sign.witnessScript)
      }

      txb.sign(index, keyPair, redeemScript, sign.hashType, value, witnessScript)

      if (sign.stage) {
        const tx = txb.buildIncomplete()
        assert.strictEqual(tx.toHex(), stages.shift())
        txb = TransactionBuilder.fromTransaction(tx, network)
      }
    })
  })

  return txb
}

function construct (f, dontSign) {
  const network = NETWORKS[f.network]
  const txb = new TransactionBuilder(network)

  if (Number.isFinite(f.version)) txb.setVersion(f.version)
  if (f.locktime !== undefined) txb.setLockTime(f.locktime)

  f.inputs.forEach(input => {
    let prevTx
    if (input.txRaw) {
      const constructed = construct(input.txRaw)
      if (input.txRaw.incomplete) prevTx = constructed.buildIncomplete()
      else prevTx = constructed.build()
    } else if (input.txHex) {
      prevTx = Transaction.fromHex(input.txHex)
    } else {
      prevTx = input.txId
    }

    let prevTxScript
    if (input.prevTxScript) {
      prevTxScript = bscript.fromASM(input.prevTxScript)
    }

    txb.addInput(prevTx, input.vout, input.sequence, prevTxScript)
  })

  f.outputs.forEach(output => {
    if (output.address) {
      txb.addOutput(output.address, output.value)
    } else {
      txb.addOutput(bscript.fromASM(output.script), output.value)
    }
  })

  if (dontSign) return txb
  return constructSign(f, txb)
}

describe('TransactionBuilder', () => {
  // constants
  const keyPair = ECPair.fromPrivateKey(Buffer.from('0000000000000000000000000000000000000000000000000000000000000001', 'hex'))
  const scripts = [
    '1BgGZ9tcN4rm9KBzDn7KprQz87SZ26SAMH',
    '1cMh228HTCiwS8ZsaakH8A8wze1JR5ZsP'
  ].map(x => {
    return baddress.toOutputScript(x)
  })
  const txHash = Buffer.from('0e7cea811c0be9f73c0aca591034396e7264473fc25c1ca45195d7417b36cbe2', 'hex')

  describe('fromTransaction', () => {
    fixtures.valid.build.forEach(f => {
      it('returns TransactionBuilder, with ' + f.description, () => {
        const network = NETWORKS[f.network || 'bitcoin']

        const tx = Transaction.fromHex(f.txHex)
        const txb = TransactionBuilder.fromTransaction(tx, network)
        const txAfter = f.incomplete ? txb.buildIncomplete() : txb.build()

        assert.strictEqual(txAfter.toHex(), f.txHex)
        assert.strictEqual(txb.network, network)
      })
    })

    fixtures.valid.fromTransaction.forEach(f => {
      it('returns TransactionBuilder, with ' + f.description, () => {
        const tx = new Transaction()

        f.inputs.forEach(input => {
          const txHash2 = Buffer.from(input.txId, 'hex').reverse()

          tx.addInput(txHash2, input.vout, undefined, bscript.fromASM(input.scriptSig))
        })

        f.outputs.forEach(output => {
          tx.addOutput(bscript.fromASM(output.script), output.value)
        })

        const txb = TransactionBuilder.fromTransaction(tx)
        const txAfter = f.incomplete ? txb.buildIncomplete() : txb.build()

        txAfter.ins.forEach((input, i) => {
          assert.strictEqual(bscript.toASM(input.script), f.inputs[i].scriptSigAfter)
        })

        txAfter.outs.forEach((output, i) => {
          assert.strictEqual(bscript.toASM(output.script), f.outputs[i].script)
        })
      })
    })

    fixtures.valid.fromTransactionSequential.forEach(f => {
      it('with ' + f.description, () => {
        const network = NETWORKS[f.network]
        const tx = Transaction.fromHex(f.txHex)
        const txb = TransactionBuilder.fromTransaction(tx, network)

        tx.ins.forEach((input, i) => {
          assert.strictEqual(bscript.toASM(input.script), f.inputs[i].scriptSig)
        })

        constructSign(f, txb)
        const txAfter = f.incomplete ? txb.buildIncomplete() : txb.build()

        txAfter.ins.forEach((input, i) => {
          assert.strictEqual(bscript.toASM(input.script), f.inputs[i].scriptSigAfter)
        })

        assert.strictEqual(txAfter.toHex(), f.txHexAfter)
      })
    })

    it('classifies transaction inputs', () => {
      const tx = Transaction.fromHex(fixtures.valid.classification.hex)
      const txb = TransactionBuilder.fromTransaction(tx)

      txb.__INPUTS.forEach(i => {
        assert.strictEqual(i.prevOutType, 'scripthash')
        assert.strictEqual(i.redeemScriptType, 'multisig')
      })
    })

    fixtures.invalid.fromTransaction.forEach(f => {
      it('throws ' + f.exception, () => {
        const tx = Transaction.fromHex(f.txHex)

        assert.throws(() => {
          TransactionBuilder.fromTransaction(tx)
        }, new RegExp(f.exception))
      })
    })
  })

  describe('addInput', () => {
    let txb
    beforeEach(() => {
      txb = new TransactionBuilder()
    })

    it('accepts a txHash, index [and sequence number]', () => {
      const vin = txb.addInput(txHash, 1, 54)
      assert.strictEqual(vin, 0)

      const txIn = txb.__TX.ins[0]
      assert.strictEqual(txIn.hash, txHash)
      assert.strictEqual(txIn.index, 1)
      assert.strictEqual(txIn.sequence, 54)
      assert.strictEqual(txb.__INPUTS[0].prevOutScript, undefined)
    })

    it('accepts a txHash, index [, sequence number and scriptPubKey]', () => {
      const vin = txb.addInput(txHash, 1, 54, scripts[1])
      assert.strictEqual(vin, 0)

      const txIn = txb.__TX.ins[0]
      assert.strictEqual(txIn.hash, txHash)
      assert.strictEqual(txIn.index, 1)
      assert.strictEqual(txIn.sequence, 54)
      assert.strictEqual(txb.__INPUTS[0].prevOutScript, scripts[1])
    })

    it('accepts a prevTx, index [and sequence number]', () => {
      const prevTx = new Transaction()
      prevTx.addOutput(scripts[0], 0)
      prevTx.addOutput(scripts[1], 1)

      const vin = txb.addInput(prevTx, 1, 54)
      assert.strictEqual(vin, 0)

      const txIn = txb.__TX.ins[0]
      assert.deepStrictEqual(txIn.hash, prevTx.getHash())
      assert.strictEqual(txIn.index, 1)
      assert.strictEqual(txIn.sequence, 54)
      assert.strictEqual(txb.__INPUTS[0].prevOutScript, scripts[1])
    })

    it('returns the input index', () => {
      assert.strictEqual(txb.addInput(txHash, 0), 0)
      assert.strictEqual(txb.addInput(txHash, 1), 1)
    })

    it('throws if SIGHASH_ALL has been used to sign any existing scriptSigs', () => {
      txb.addInput(txHash, 0)
      txb.addOutput(scripts[0], 1000)
      txb.sign(0, keyPair)

      assert.throws(() => {
        txb.addInput(txHash, 0)
      }, /No, this would invalidate signatures/)
    })
  })

  describe('addOutput', () => {
    let txb
    beforeEach(() => {
      txb = new TransactionBuilder()
    })

    it('accepts an address string and value', () => {
      const { address } = payments.p2pkh({ pubkey: keyPair.publicKey })
      const vout = txb.addOutput(address, 1000)
      assert.strictEqual(vout, 0)

      const txout = txb.__TX.outs[0]
      assert.deepStrictEqual(txout.script, scripts[0])
      assert.strictEqual(txout.value, 1000)
    })

    it('accepts a ScriptPubKey and value', () => {
      const vout = txb.addOutput(scripts[0], 1000)
      assert.strictEqual(vout, 0)

      const txout = txb.__TX.outs[0]
      assert.deepStrictEqual(txout.script, scripts[0])
      assert.strictEqual(txout.value, 1000)
    })

    it('throws if address is of the wrong network', () => {
      assert.throws(() => {
        txb.addOutput('2NGHjvjw83pcVFgMcA7QvSMh2c246rxLVz9', 1000)
      }, /2NGHjvjw83pcVFgMcA7QvSMh2c246rxLVz9 has no matching Script/)
    })

    it('add second output after signed first input with SIGHASH_NONE', () => {
      txb.addInput(txHash, 0)
      txb.addOutput(scripts[0], 2000)
      txb.sign(0, keyPair, undefined, Transaction.SIGHASH_NONE)
      assert.strictEqual(txb.addOutput(scripts[1], 9000), 1)
    })

    it('add first output after signed first input with SIGHASH_NONE', () => {
      txb.addInput(txHash, 0)
      txb.sign(0, keyPair, undefined, Transaction.SIGHASH_NONE)
      assert.strictEqual(txb.addOutput(scripts[0], 2000), 0)
    })

    it('add second output after signed first input with SIGHASH_SINGLE', () => {
      txb.addInput(txHash, 0)
      txb.addOutput(scripts[0], 2000)
      txb.sign(0, keyPair, undefined, Transaction.SIGHASH_SINGLE)
      assert.strictEqual(txb.addOutput(scripts[1], 9000), 1)
    })

    it('add first output after signed first input with SIGHASH_SINGLE', () => {
      txb.addInput(txHash, 0)
      txb.sign(0, keyPair, undefined, Transaction.SIGHASH_SINGLE)
      assert.throws(() => {
        txb.addOutput(scripts[0], 2000)
      }, /No, this would invalidate signatures/)
    })

    it('throws if SIGHASH_ALL has been used to sign any existing scriptSigs', () => {
      txb.addInput(txHash, 0)
      txb.addOutput(scripts[0], 2000)
      txb.sign(0, keyPair)

      assert.throws(() => {
        txb.addOutput(scripts[1], 9000)
      }, /No, this would invalidate signatures/)
    })
  })

  describe('setLockTime', () => {
    it('throws if if there exist any scriptSigs', () => {
      const txb = new TransactionBuilder()
      txb.addInput(txHash, 0)
      txb.addOutput(scripts[0], 100)
      txb.sign(0, keyPair)

      assert.throws(() => {
        txb.setLockTime(65535)
      }, /No, this would invalidate signatures/)
    })
  })

  describe('sign', () => {
    it('supports the alternative abstract interface { publicKey, sign }', () => {
      const keyPair = {
        publicKey: ECPair.makeRandom({ rng: () => { return Buffer.alloc(32, 1) } }).publicKey,
        sign: hash => { return Buffer.alloc(64, 0x5f) }
      }

      const txb = new TransactionBuilder()
      txb.setVersion(1)
      txb.addInput('ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff', 1)
      txb.addOutput('1111111111111111111114oLvT2', 100000)
      txb.sign(0, keyPair)
      assert.strictEqual(txb.build().toHex(), '0100000001ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff010000006a47304402205f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f02205f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f0121031b84c5567b126440995d3ed5aaba0565d71e1834604819ff9c17f5e9d5dd078fffffffff01a0860100000000001976a914000000000000000000000000000000000000000088ac00000000')
    })

    fixtures.invalid.sign.forEach(f => {
      it('throws ' + f.exception + (f.description ? ' (' + f.description + ')' : ''), () => {
        const txb = construct(f, true)

        let threw = false
        f.inputs.forEach((input, index) => {
          input.signs.forEach(sign => {
            const keyPairNetwork = NETWORKS[sign.network || f.network]
            const keyPair2 = ECPair.fromWIF(sign.keyPair, keyPairNetwork)
            let redeemScript
            let witnessScript

            if (sign.redeemScript) {
              redeemScript = bscript.fromASM(sign.redeemScript)
            }

            if (sign.witnessScript) {
              witnessScript = bscript.fromASM(sign.witnessScript)
            }

            if (sign.throws) {
              assert.throws(() => {
                txb.sign(index, keyPair2, redeemScript, sign.hashType, sign.value, witnessScript)
              }, new RegExp(f.exception))
              threw = true
            } else {
              txb.sign(index, keyPair2, redeemScript, sign.hashType, sign.value, witnessScript)
            }
          })
        })

        assert.strictEqual(threw, true)
      })
    })
  })

  describe('build', () => {
    fixtures.valid.build.forEach(f => {
      it('builds "' + f.description + '"', () => {
        const txb = construct(f)
        const tx = f.incomplete ? txb.buildIncomplete() : txb.build()

        assert.strictEqual(tx.toHex(), f.txHex)
      })
    })

    // TODO: remove duplicate test code
    fixtures.invalid.build.forEach(f => {
      describe('for ' + (f.description || f.exception), () => {
        it('throws ' + f.exception, () => {
          assert.throws(() => {
            let txb
            if (f.txHex) {
              txb = TransactionBuilder.fromTransaction(Transaction.fromHex(f.txHex))
            } else {
              txb = construct(f)
            }

            txb.build()
          }, new RegExp(f.exception))
        })

        // if throws on incomplete too, enforce that
        if (f.incomplete) {
          it('throws ' + f.exception, () => {
            assert.throws(() => {
              let txb
              if (f.txHex) {
                txb = TransactionBuilder.fromTransaction(Transaction.fromHex(f.txHex))
              } else {
                txb = construct(f)
              }

              txb.buildIncomplete()
            }, new RegExp(f.exception))
          })
        } else {
          it('does not throw if buildIncomplete', () => {
            let txb
            if (f.txHex) {
              txb = TransactionBuilder.fromTransaction(Transaction.fromHex(f.txHex))
            } else {
              txb = construct(f)
            }

            txb.buildIncomplete()
          })
        }
      })
    })

    it('for incomplete with 0 signatures', () => {
      const randomTxData = '0100000000010100010000000000000000000000000000000000000000000000000000000000000000000000ffffffff01e8030000000000001976a9144c9c3dfac4207d5d8cb89df5722cb3d712385e3f88ac02483045022100aa5d8aa40a90f23ce2c3d11bc845ca4a12acd99cbea37de6b9f6d86edebba8cb022022dedc2aa0a255f74d04c0b76ece2d7c691f9dd11a64a8ac49f62a99c3a05f9d01232103596d3451025c19dbbdeb932d6bf8bfb4ad499b95b6f88db8899efac102e5fc71ac00000000'
      const randomAddress = '1BgGZ9tcN4rm9KBzDn7KprQz87SZ26SAMH'

      const randomTx = Transaction.fromHex(randomTxData)
      let tx = new TransactionBuilder()
      tx.addInput(randomTx, 0)
      tx.addOutput(randomAddress, 1000)
      tx = tx.buildIncomplete()
      assert(tx)
    })

    it('for incomplete P2SH with 0 signatures', () => {
      const inp = Buffer.from('010000000173120703f67318aef51f7251272a6816d3f7523bb25e34b136d80be959391c100000000000ffffffff0100c817a80400000017a91471a8ec07ff69c6c4fee489184c462a9b1b9237488700000000', 'hex') // arbitrary P2SH input
      const inpTx = Transaction.fromBuffer(inp)

      const txb = new TransactionBuilder(NETWORKS.testnet)
      txb.addInput(inpTx, 0)
      txb.addOutput('2NAkqp5xffoomp5RLBcakuGpZ12GU4twdz4', 1e8) // arbitrary output

      txb.buildIncomplete()
    })

    it('for incomplete P2WPKH with 0 signatures', () => {
      const inp = Buffer.from('010000000173120703f67318aef51f7251272a6816d3f7523bb25e34b136d80be959391c100000000000ffffffff0100c817a8040000001600141a15805e1f4040c9f68ccc887fca2e63547d794b00000000', 'hex')
      const inpTx = Transaction.fromBuffer(inp)

      const txb = new TransactionBuilder(NETWORKS.testnet)
      txb.addInput(inpTx, 0)
      txb.addOutput('2NAkqp5xffoomp5RLBcakuGpZ12GU4twdz4', 1e8) // arbitrary output

      txb.buildIncomplete()
    })

    it('for incomplete P2WSH with 0 signatures', () => {
      const inpTx = Transaction.fromBuffer(Buffer.from('010000000173120703f67318aef51f7251272a6816d3f7523bb25e34b136d80be959391c100000000000ffffffff0100c817a80400000022002072df76fcc0b231b94bdf7d8c25d7eef4716597818d211e19ade7813bff7a250200000000', 'hex'))

      const txb = new TransactionBuilder(NETWORKS.testnet)
      txb.addInput(inpTx, 0)
      txb.addOutput('2NAkqp5xffoomp5RLBcakuGpZ12GU4twdz4', 1e8) // arbitrary output

      txb.buildIncomplete()
    })
  })

  describe('multisig', () => {
    fixtures.valid.multisig.forEach(f => {
      it(f.description, () => {
        const network = NETWORKS[f.network]
        let txb = construct(f, true)
        let tx

        f.inputs.forEach((input, i) => {
          const redeemScript = bscript.fromASM(input.redeemScript)

          input.signs.forEach(sign => {
            // rebuild the transaction each-time after the first
            if (tx) {
              // manually override the scriptSig?
              if (sign.scriptSigBefore) {
                tx.ins[i].script = bscript.fromASM(sign.scriptSigBefore)
              }

              // rebuild
              txb = TransactionBuilder.fromTransaction(tx, network)
            }

            const keyPair2 = ECPair.fromWIF(sign.keyPair, network)
            txb.sign(i, keyPair2, redeemScript, sign.hashType)

            // update the tx
            tx = txb.buildIncomplete()

            // now verify the serialized scriptSig is as expected
            assert.strictEqual(bscript.toASM(tx.ins[i].script), sign.scriptSig)
          })
        })

        tx = txb.build()
        assert.strictEqual(tx.toHex(), f.txHex)
      })
    })
  })

  describe('various edge case', () => {
    const network = NETWORKS.testnet

    it('should warn of high fee for segwit transaction based on VSize, not Size', () => {
      const rawtx = '01000000000104fdaac89627208b4733484ca56bc291f4cf4fa8d7c5f29893c52b46788a0a' +
      '1df90000000000fffffffffdaac89627208b4733484ca56bc291f4cf4fa8d7c5f29893c52b46788a0a1df9' +
      '0100000000ffffffffa2ef7aaab316a3e5b5b0a78d1d35c774b95a079f9f0c762277a49caf1f26bca40000' +
      '000000ffffffffa2ef7aaab316a3e5b5b0a78d1d35c774b95a079f9f0c762277a49caf1f26bca401000000' +
      '00ffffffff0100040000000000001976a914cf307285359ab7ef6a2daa0522c7908ddf5fe7a988ac024730' +
      '440220113324438816338406841775e079b04c50d04f241da652a4035b1017ea1ecf5502205802191eb49c' +
      '54bf2a5667aea72e51c3ca92085efc60f12d1ebda3a64aff343201210283409659355b6d1cc3c32decd5d5' +
      '61abaac86c37a353b52895a5e6c196d6f44802483045022100dc2892874e6d8708e3f5a058c5c9263cdf03' +
      '969492270f89ee4933caf6daf8bb0220391dfe61a002709b63b9d64422d3db09b727839d1287e10a128a5d' +
      'b52a82309301210283409659355b6d1cc3c32decd5d561abaac86c37a353b52895a5e6c196d6f448024830' +
      '450221009e3ed3a6ae93a018f443257b43e47b55cf7f7f3547d8807178072234686b22160220576121cfe6' +
      '77c7eddf5575ea0a7c926247df6eca723c4f85df306e8bc08ea2df01210283409659355b6d1cc3c32decd5' +
      'd561abaac86c37a353b52895a5e6c196d6f44802473044022007be81ffd4297441ab10e740fc9bab9545a2' +
      '194a565cd6aa4cc38b8eaffa343402201c5b4b61d73fa38e49c1ee68cc0e6dfd2f5dae453dd86eb142e87a' +
      '0bafb1bc8401210283409659355b6d1cc3c32decd5d561abaac86c37a353b52895a5e6c196d6f44800000000'
      const txb = TransactionBuilder.fromTransaction(Transaction.fromHex(rawtx))
      txb.__INPUTS[0].value = 241530
      txb.__INPUTS[1].value = 241530
      txb.__INPUTS[2].value = 248920
      txb.__INPUTS[3].value = 248920

      assert.throws(() => {
        txb.build()
      }, new RegExp('Transaction has absurd fees'))
    })

    it('should classify witness inputs with witness = true during multisigning', () => {
      const keyPair = ECPair.fromWIF('cRAwuVuVSBZMPu7hdrYvMCZ8eevzmkExjFbaBLhqnDdrezxN3nTS', network)
      const witnessScript = Buffer.from('522102bbbd6eb01efcbe4bd9664b886f26f69de5afcb2e479d72596c8bf21929e352e22102d9c3f7180ef13ec5267723c9c2ffab56a4215241f837502ea8977c8532b9ea1952ae', 'hex')
      const redeemScript = Buffer.from('002024376a0a9abab599d0e028248d48ebe817bc899efcffa1cd2984d67289daf5af', 'hex')
      const scriptPubKey = Buffer.from('a914b64f1a3eacc1c8515592a6f10457e8ff90e4db6a87', 'hex')
      const txb = new TransactionBuilder(network)
      txb.setVersion(1)
      txb.addInput('a4696c4b0cd27ec2e173ab1fa7d1cc639a98ee237cec95a77ca7ff4145791529', 1, 0xffffffff, scriptPubKey)
      txb.addOutput(scriptPubKey, 99000)
      txb.sign(0, keyPair, redeemScript, null, 100000, witnessScript)

      // 2-of-2 signed only once
      const tx = txb.buildIncomplete()

      // Only input is segwit, so txid should be accurate with the final tx
      assert.strictEqual(tx.getId(), 'f15d0a65b21b4471405b21a099f8b18e1ae4d46d55efbd0f4766cf11ad6cb821')

      const txHex = tx.toHex()
      TransactionBuilder.fromTransaction(Transaction.fromHex(txHex))
    })

    it('should handle badly pre-filled OP_0s', () => {
      // OP_0 is used where a signature is missing
      const redeemScripSig = bscript.fromASM('OP_0 OP_0 3045022100daf0f4f3339d9fbab42b098045c1e4958ee3b308f4ae17be80b63808558d0adb02202f07e3d1f79dc8da285ae0d7f68083d769c11f5621ebd9691d6b48c0d4283d7d01 52410479be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b84104c6047f9441ed7d6d3045406e95c07cd85c778e4b8cef3ca7abac09b95c709ee51ae168fea63dc339a3c58419466ceaeef7f632653266d0e1236431a950cfe52a4104f9308a019258c31049344f85f89d5229b531c845836f99b08601f113bce036f9388f7b0f632de8140fe337e62a37f3566500a99934c2231b6cb9fd7584b8e67253ae')
      const redeemScript = bscript.fromASM('OP_2 0479be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8 04c6047f9441ed7d6d3045406e95c07cd85c778e4b8cef3ca7abac09b95c709ee51ae168fea63dc339a3c58419466ceaeef7f632653266d0e1236431a950cfe52a 04f9308a019258c31049344f85f89d5229b531c845836f99b08601f113bce036f9388f7b0f632de8140fe337e62a37f3566500a99934c2231b6cb9fd7584b8e672 OP_3 OP_CHECKMULTISIG')

      const tx = new Transaction()
      tx.addInput(Buffer.from('cff58855426469d0ef16442ee9c644c4fb13832467bcbc3173168a7916f07149', 'hex'), 0, undefined, redeemScripSig)
      tx.addOutput(Buffer.from('76a914aa4d7985c57e011a8b3dd8e0e5a73aaef41629c588ac', 'hex'), 1000)

      // now import the Transaction
      const txb = TransactionBuilder.fromTransaction(tx, NETWORKS.testnet)

      const keyPair2 = ECPair.fromWIF('91avARGdfge8E4tZfYLoxeJ5sGBdNJQH4kvjJoQFacbgx3cTMqe', network)
      txb.sign(0, keyPair2, redeemScript)

      const tx2 = txb.build()
      assert.strictEqual(tx2.getId(), 'eab59618a564e361adef6d918bd792903c3d41bcf1220137364fb847880467f9')
      assert.strictEqual(bscript.toASM(tx2.ins[0].script), 'OP_0 3045022100daf0f4f3339d9fbab42b098045c1e4958ee3b308f4ae17be80b63808558d0adb02202f07e3d1f79dc8da285ae0d7f68083d769c11f5621ebd9691d6b48c0d4283d7d01 3045022100a346c61738304eac5e7702188764d19cdf68f4466196729db096d6c87ce18cdd022018c0e8ad03054b0e7e235cda6bedecf35881d7aa7d94ff425a8ace7220f38af001 52410479be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b84104c6047f9441ed7d6d3045406e95c07cd85c778e4b8cef3ca7abac09b95c709ee51ae168fea63dc339a3c58419466ceaeef7f632653266d0e1236431a950cfe52a4104f9308a019258c31049344f85f89d5229b531c845836f99b08601f113bce036f9388f7b0f632de8140fe337e62a37f3566500a99934c2231b6cb9fd7584b8e67253ae')
    })

    it('should not classify blank scripts as nonstandard', () => {
      let txb = new TransactionBuilder()
      txb.setVersion(1)
      txb.addInput('aa94ab02c182214f090e99a0d57021caffd0f195a81c24602b1028b130b63e31', 0)

      const incomplete = txb.buildIncomplete().toHex()
      const keyPair = ECPair.fromWIF('L1uyy5qTuGrVXrmrsvHWHgVzW9kKdrp27wBC7Vs6nZDTF2BRUVwy')

      // sign, as expected
      txb.addOutput('1Gokm82v6DmtwKEB8AiVhm82hyFSsEvBDK', 15000)
      txb.sign(0, keyPair)
      const txId = txb.build().getId()
      assert.strictEqual(txId, '54f097315acbaedb92a95455da3368eb45981cdae5ffbc387a9afc872c0f29b3')

      // and, repeat
      txb = TransactionBuilder.fromTransaction(Transaction.fromHex(incomplete))
      txb.addOutput('1Gokm82v6DmtwKEB8AiVhm82hyFSsEvBDK', 15000)
      txb.sign(0, keyPair)
      const txId2 = txb.build().getId()
      assert.strictEqual(txId, txId2)
    })
  })
})