Creating a basic example of making a Tx

transaction.go

@@ -0,0 +1,80 @@
+package bitcoin
+
+import (
+	"errors"
+
+	"github.com/bitcoinsv/bsvutil"
+	"github.com/libsv/libsv/transaction"
+	"github.com/libsv/libsv/transaction/output"
+	"github.com/libsv/libsv/transaction/signature"
+)
+
+// Utxo is an unspent transaction output
+type Utxo struct {
+	Satoshis  uint64 `json:"satoshis"`
+	ScriptSig string `json:"string"`
+	TxID      string `json:"tx_id"`
+	Vout      uint32 `json:"vout"`
+}
+
+// PayToAddress is the pay-to-address
+type PayToAddress struct {
+	Address  string `json:"address"`
+	Satoshis uint64 `json:"satoshis"`
+}
+
+// OpReturnData is the op return data to include in the tx
+type OpReturnData struct {
+	Data string `json:"data"`
+}
+
+// CreateTx will create a basic transaction
+func CreateTx(utxos []*Utxo, addresses []*PayToAddress, opReturns []*OpReturnData, wif string) (string, error) {
+
+	// Missing utxos
+	if len(utxos) == 0 {
+		return "", errors.New("utxos are required to create a tx")
+	}
+
+	// Start creating a new transaction
+	tx := transaction.New()
+
+	// Loop all utxos and add to the transaction
+	var err error
+	for _, utxo := range utxos {
+		if err = tx.From(utxo.TxID, utxo.Vout, utxo.ScriptSig, utxo.Satoshis); err != nil {
+			return "", err
+		}
+	}
+
+	// Loop any pay addresses
+	for _, address := range addresses {
+		if err = tx.PayTo(address.Address, address.Satoshis); err != nil {
+			return "", err
+		}
+	}
+
+	// Loop any op returns
+	var outPut *output.Output
+	for _, op := range opReturns {
+		if outPut, err = output.NewOpReturn([]byte(op.Data)); err != nil {
+			return "", err
+		}
+		tx.AddOutput(outPut)
+	}
+
+	// Decode the WIF
+	var decodedWif *bsvutil.WIF
+	if decodedWif, err = bsvutil.DecodeWIF(wif); err != nil {
+		return "", err
+	}
+
+	// Sign the transaction
+	signer := signature.InternalSigner{PrivateKey: decodedWif.PrivKey, SigHashFlag: 0}
+	if err = tx.SignAuto(&signer); err != nil {
+		return "", err
+	}
+
+	// Return the transaction as a raw string
+	return tx.ToString(), nil
+}

transaction_test.go

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+package bitcoin
+
+import "testing"
+
+// TestCreateTx will test the method CreateTx()
+func TestCreateTx(t *testing.T) {
+
+	// Example from: https://github.com/libsv/libsv
+
+	// Use a new UTXO
+	utxo := &Utxo{
+		TxID:      "b7b0650a7c3a1bd4716369783876348b59f5404784970192cec1996e86950576",
+		Vout:      0,
+		ScriptSig: "76a9149cbe9f5e72fa286ac8a38052d1d5337aa363ea7f88ac",
+		Satoshis:  1000,
+	}
+
+	// Add a pay-to address
+	payTo := &PayToAddress{
+		Address:  "1C8bzHM8XFBHZ2ZZVvFy2NSoAZbwCXAicL",
+		Satoshis: 500,
+	}
+
+	// Add some op return data
+	opReturns := &OpReturnData{Data: "This is the example data!"}
+
+	// Generate the TX
+	rawTx, err := CreateTx([]*Utxo{utxo}, []*PayToAddress{payTo}, []*OpReturnData{opReturns}, "L3VJH2hcRGYYG6YrbWGmsxQC1zyYixA82YjgEyrEUWDs4ALgk8Vu")
+	if err != nil {
+		t.Fatalf("error occurred: %s", err.Error())
+	}
+
+	// Show the results
+	t.Logf("created tx: %s", rawTx)
+}