fix blockchain_test

blockchain/block.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"crypto/sha256"
 	"encoding/gob"
+	"fmt"
 	"log"
 	"time"
 )
@@ -38,6 +39,17 @@ func DeserializeBlock(d []byte) *Block {
 	return &block
 }
 
+// Used for debuging.
+func (b *Block) String() string {
+	res := fmt.Sprintf("Block created at %v\n", b.Timestamp)
+	for id, tx := range b.Transactions {
+		res += fmt.Sprintf("Transaction %v: %v\n", id, *tx)
+	}
+	res += fmt.Sprintf("previous blockhash: %v\n", b.PrevBlockHash)
+	res += fmt.Sprintf("hash: %v\n", b.Hash)
+	return res
+}
+
 // HashTransactions returns a hash of the transactions in the block
 func (b *Block) HashTransactions() []byte {
 	var txHashes [][]byte

blockchain/block_test.go

@@ -2,6 +2,7 @@ package blockchain
 
 import (
 	"bytes"
+	"fmt"
 	"testing"
 )
 
@@ -23,4 +24,6 @@ func TestBlockSerialize(t *testing.T) {
 	if bytes.Compare(block.Hash, deserializedBlock.Hash) != 0 {
 		t.Errorf("Serialize or Deserialize incorrect at Hash.")
 	}
+
+	fmt.Println(block)
 }

blockchain/blockchain.go

@@ -19,11 +19,11 @@ func (bc *Blockchain) FindUnspentTransactions(address string) []Transaction {
 	for index := len(bc.blocks) - 1; index >= 0; index-- {
 		block := bc.blocks[index]
 
-	BreakTransaction:
 		for _, tx := range block.Transactions {
 			txID := hex.EncodeToString(tx.ID)
 
 			idx := -1
+			// TODO(minhdoan): Optimize this.
 			if spentTXOs[txID] != nil {
 				idx = 0
 			}
@@ -35,7 +35,15 @@ func (bc *Blockchain) FindUnspentTransactions(address string) []Transaction {
 
 				if txOutput.Address == address {
 					unspentTXs = append(unspentTXs, *tx)
-					continue BreakTransaction
+					// Break because of the assumption that each address appears once in output.
+					break
+				}
+			}
+
+			for _, txInput := range tx.TxInput {
+				if address == txInput.Address {
+					ID := hex.EncodeToString(txInput.TxID)
+					spentTXOs[ID] = append(spentTXOs[ID], txInput.TxOutputIndex)
 				}
 			}
 		}

blockchain/blockchain_test.go

@@ -47,10 +47,8 @@ func TestAddNewTransferAmount(t *testing.T) {
 		t.Error("Failed to add new transfer")
 	}
 
-	t.Log(len(bc.blocks))
 	bc = bc.AddNewTransferAmount("minh", "rj", DefaultCoinbaseValue-2)
 
-	t.Log(len(bc.blocks))
 	if bc != nil {
 		t.Error("minh should not have enough fun to make the transfer")
 	}

blockchain/transaction.go

@@ -60,38 +60,31 @@ func NewCoinbaseTX(to, data string) *Transaction {
 	return &tx
 }
 
-// NewUTXOTransaction creates a new transaction
-func NewUTXOTransaction(from, to string, amount int, bc *Blockchain) *Transaction {
-	var inputs []TXInput
-	var outputs []TXOutput
-
-	acc, validOutputs := bc.FindSpendableOutputs(from, amount)
-
-	if acc < amount {
-		return nil
-	}
+// Used for debuging.
+func (txInput *TXInput) String() string {
+	res := fmt.Sprintf("TxID: %v, ", hex.EncodeToString(txInput.TxID))
+	res += fmt.Sprintf("TxOutputIndex: %v, ", txInput.TxOutputIndex)
+	res += fmt.Sprintf("Address: %v", txInput.Address)
+	return res
+}
 
-	// Build a list of inputs
-	for txid, outs := range validOutputs {
-		txID, err := hex.DecodeString(txid)
-		if err != nil {
-			return nil
-		}
+// Used for debuging.
+func (txOutput *TXOutput) String() string {
+	res := fmt.Sprintf("Value: %v, ", txOutput.Value)
+	res += fmt.Sprintf("Address: %v", txOutput.Address)
+	return res
+}
 
-		for _, out := range outs {
-			input := TXInput{txID, out, from}
-			inputs = append(inputs, input)
+// Used for debuging.
+func (tx *Transaction) String() string {
+	res := fmt.Sprintf("ID: %v\n", hex.EncodeToString(tx.ID))
+	res += fmt.Sprintf("TxInput:\n")
+	for id, value := range tx.TxInput {
+		res += fmt.Sprintf("%v: %v\n", id, value.String())
 	}
+	res += fmt.Sprintf("TxOutput:\n")
+	for id, value := range tx.TxOutput {
+		res += fmt.Sprintf("%v: %v\n", id, value.String())
 	}
-
-	// Build a list of outputs
-	outputs = append(outputs, TXOutput{amount, to})
-	if acc > amount {
-		outputs = append(outputs, TXOutput{acc - amount, from}) // a change
-	}
-
-	tx := Transaction{nil, inputs, outputs}
-	tx.SetID()
-
-	return &tx
+	return res
 }