bdk-ffi/bdk-swift/Tests/BitcoinDevKitTests/LiveTxBuilderTests.swift

import XCTest
@testable import BitcoinDevKit

final class LiveTxBuilderTests: XCTestCase {
    func testTxBuilder() throws {
        let descriptor = try Descriptor(
            descriptor: "wpkh(tprv8ZgxMBicQKsPf2qfrEygW6fdYseJDDrVnDv26PH5BHdvSuG6ecCbHqLVof9yZcMoM31z9ur3tTYbSnr1WBqbGX97CbXcmp5H6qeMpyvx35B/84h/1h/0h/0/*)",
            network: Network.testnet
        )
        let wallet = try Wallet.newNoPersist(
            descriptor: descriptor,
            changeDescriptor: nil,
            network: .testnet
        )
        let esploraClient = EsploraClient(url: "https://mempool.space/testnet/api")
        let update = try esploraClient.scan(
            wallet: wallet,
            stopGap: 10,
            parallelRequests: 1
        )
        try wallet.applyUpdate(update: update)

        XCTAssertGreaterThan(wallet.getBalance().total, UInt64(0), "Wallet must have positive balance, please add funds")

        let recipient: Address = try Address(address: "tb1qrnfslnrve9uncz9pzpvf83k3ukz22ljgees989", network: .testnet)
        let psbt: PartiallySignedTransaction = try TxBuilder()
            .addRecipient(script: recipient.scriptPubkey(), amount: 4200)
            .feeRate(satPerVbyte: 2.0)
            .finish(wallet: wallet)

        print(psbt.serialize())
        XCTAssertTrue(psbt.serialize().hasPrefix("cHNi"), "PSBT should start with cHNI")
    }
}