Add some tests (#828)

* Add tests

* Add tests

* Add tests

* Add tests

* Fix code style

* Remove unnecessary tests

src/config/config_test.go

@@ -0,0 +1,54 @@
+package config
+
+import (
+	"bytes"
+	"encoding/hex"
+	"testing"
+)
+
+func TestConfig_Keys(t *testing.T) {
+	var nodeConfig NodeConfig
+	nodeConfig.NewKeys()
+
+	publicKey1, err := hex.DecodeString(nodeConfig.PublicKey)
+
+	if err != nil {
+		t.Fatal("can not decode generated public key")
+	}
+
+	if len(publicKey1) == 0 {
+		t.Fatal("empty public key generated")
+	}
+
+	privateKey1, err := hex.DecodeString(nodeConfig.PrivateKey)
+
+	if err != nil {
+		t.Fatal("can not decode generated private key")
+	}
+
+	if len(privateKey1) == 0 {
+		t.Fatal("empty private key generated")
+	}
+
+	nodeConfig.NewKeys()
+
+	publicKey2, err := hex.DecodeString(nodeConfig.PublicKey)
+
+	if err != nil {
+		t.Fatal("can not decode generated public key")
+	}
+
+	if bytes.Equal(publicKey2, publicKey1) {
+		t.Fatal("same public key generated")
+	}
+
+	privateKey2, err := hex.DecodeString(nodeConfig.PrivateKey)
+
+	if err != nil {
+		t.Fatal("can not decode generated private key")
+	}
+
+	if bytes.Equal(privateKey2, privateKey1) {
+		t.Fatal("same private key generated")
+	}
+}