Implement the creator role in bip174.

generate_a_unsigned_psbt.rs

/// impl bip174 by rust-bitcoin crate
/// Creates the PSBT, in BIP174 parlance this is the 'Creator'.

/// reference
/// https://crates.io/crates/bitcoin
/// https://github.com/bitcoin/bips/blob/master/bip-0174.mediawiki   
use third_party::bitcoin::psbt::{Psbt};
use third_party::bitcoin::{Amount, OutPoint, ScriptBuf, Sequence, Transaction, Txid, TxIn, TxOut, Witness};
use third_party::bitcoin_hashes::hex::FromHex;
use third_party::{hex};

#[test]
fn test_construct_unsigned_psbt(){
    /// Creates the PSBT, in BIP174 parlance this is the 'Creator'.
    let unsigned_tx = Transaction{
        version:third_party::bitcoin::transaction::Version::TWO,
        lock_time: third_party::bitcoin::blockdata::locktime::absolute::LockTime::ZERO,
        input: vec![
            TxIn{
                previous_output: OutPoint{
                txid: Txid::from_str("75ddabb27b8845f5247975c8a5ba7c6f336c4570708ebe230caf6db5217ae858").unwrap(),
                vout: 0,
            },
            script_sig: ScriptBuf::new(),
            sequence:Sequence::MAX,
            witness: Witness::default(),
            },
            TxIn{
                previous_output: OutPoint{
                txid: Txid::from_str("1dea7cd05979072a3578cab271c02244ea8a090bbb46aa680a65ecd027048d83").unwrap(),
                vout: 1,
            },
            script_sig: ScriptBuf::new(),
            sequence:Sequence::MAX,
            witness: Witness::default(),
            }
        ],
        output: vec![
            TxOut {
                value: Amount::from_sat(149990000),
                script_pubkey: ScriptBuf::from_hex("0014d85c2b71d0060b09c9886aeb815e50991dda124d").unwrap(),
            },
            TxOut {
                value: Amount::from_sat(100000000),
                script_pubkey: ScriptBuf::from_hex("001400aea9a2e5f0f876a588df5546e8742d1d87008f").unwrap(),
            },
        ],
    };
    let psbt = Psbt::from_unsigned_tx(unsigned_tx).unwrap();
    // serialize psbt
    let serialized_psbt = psbt.serialize();
    let hex_str = hex::encode(serialized_psbt);
    assert_eq!(
        "70736274ff01009a020000000258e87a21b56daf0c23be8e7070456c336f7cbaa5c8757924f545887bb2abdd750000000000ffffffff838d0427d0ec650a68aa46bb0b098aea4422c071b2ca78352a077959d07cea1d0100000000ffffffff0270aaf00800000000160014d85c2b71d0060b09c9886aeb815e50991dda124d00e1f5050000000016001400aea9a2e5f0f876a588df5546e8742d1d87008f000000000000000000",
        hex_str
    )
}