pp marshalling with testing

Signed-off-by: Angelo De Caro <adc@zurich.ibm.com>

Author: adecaro

token/core/common/encoding/pp/pp.go

@@ -1,15 +1,26 @@
+/*
+Copyright IBM Corp. All Rights Reserved.
+
+SPDX-License-Identifier: Apache-2.0
+*/
+
 package pp
 
 import (
+	"github.com/hyperledger-labs/fabric-smart-client/pkg/utils/errors"
 	"github.com/hyperledger-labs/fabric-token-sdk/token/core/common/encoding/json"
 	"github.com/hyperledger-labs/fabric-token-sdk/token/driver/protos-go/pp"
 )
 
 // Marshal marshals the passed public parameters
 func Marshal(pp *pp.PublicParameters) ([]byte, error) {
+	if pp == nil {
+		return nil, errors.New("nil public parameters")
+	}
 	return json.Marshal(pp)
 }
 
+// Unmarshal unmarshals the passed slice into an instance of pp.PublicParameters
 func Unmarshal(raw []byte) (*pp.PublicParameters, error) {
 	pp := &pp.PublicParameters{}
 	if err := json.Unmarshal(raw, pp); err != nil {

token/core/common/encoding/pp/pp_test.go

@@ -0,0 +1,48 @@
+/*
+Copyright IBM Corp. All Rights Reserved.
+
+SPDX-License-Identifier: Apache-2.0
+*/
+
+package pp
+
+import (
+	"testing"
+
+	"github.com/hyperledger-labs/fabric-token-sdk/token/driver/protos-go/pp"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestSerialization(t *testing.T) {
+	// Marshal
+
+	// check failures
+	_, err := Marshal(nil)
+	assert.Error(t, err)
+	assert.EqualError(t, err, "nil public parameters")
+
+	// success
+	pp := &pp.PublicParameters{
+		Identifier: "pineapple",
+		Raw:        []byte{1, 2, 3},
+	}
+	res, err := Marshal(pp)
+	assert.NoError(t, err)
+
+	// Unmarshall
+
+	// success
+	pp2, err := Unmarshal(res)
+	assert.NoError(t, err)
+	assert.Equal(t, pp, pp2)
+
+	// failure
+	_, err = Unmarshal([]byte{})
+	assert.Error(t, err)
+
+	_, err = Unmarshal(nil)
+	assert.Error(t, err)
+
+	_, err = Unmarshal([]byte{1, 2, 3})
+	assert.Error(t, err)
+}