wallet: add GetAccount() method to Wallet

It is useful to be able to get account specified by script hash.

pkg/wallet/wallet.go

@@ -6,6 +6,7 @@ import (
 	"os"
 
 	"github.com/CityOfZion/neo-go/pkg/crypto/keys"
+	"github.com/CityOfZion/neo-go/pkg/util"
 )
 
 const (
@@ -117,3 +118,14 @@ func (w *Wallet) Close() {
 		rc.Close()
 	}
 }
+
+// GetAccount returns account corresponding to the provided scripthash.
+func (w *Wallet) GetAccount(h util.Uint160) *Account {
+	for _, acc := range w.Accounts {
+		if c := acc.Contract; c != nil && h.Equals(c.ScriptHash()) {
+			return acc
+		}
+	}
+
+	return nil
+}

pkg/wallet/wallet_test.go

@@ -6,6 +6,7 @@ import (
 	"os"
 	"testing"
 
+	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
 
@@ -119,3 +120,28 @@ func removeWallet(t *testing.T, walletPath string) {
 	err := os.RemoveAll(walletPath)
 	require.NoError(t, err)
 }
+
+func TestWallet_GetAccount(t *testing.T) {
+	wallet := checkWalletConstructor(t)
+	accounts := []*Account{
+		{
+			Contract: &Contract{
+				Script: []byte{0, 1, 2, 3},
+			},
+		},
+		{
+			Contract: &Contract{
+				Script: []byte{3, 2, 1, 0},
+			},
+		},
+	}
+
+	for _, acc := range accounts {
+		wallet.AddAccount(acc)
+	}
+
+	for i, acc := range accounts {
+		h := acc.Contract.ScriptHash()
+		assert.Equal(t, acc, wallet.GetAccount(h), "can't get %d account", i)
+	}
+}