state: implement SignedDataSource on ChangeStateRequest message

state/sign.go

@@ -1,5 +1,9 @@
 package state
 
+import (
+	"io"
+)
+
 // SignedData returns payload bytes of the request.
 //
 // Always returns an empty slice.
@@ -34,3 +38,34 @@ func (m DumpRequest) SignedData() ([]byte, error) {
 func (m DumpVarsRequest) SignedData() ([]byte, error) {
 	return make([]byte, 0), nil
 }
+
+// SignedData returns payload bytes of the request.
+func (m ChangeStateRequest) SignedData() ([]byte, error) {
+	data := make([]byte, m.SignedDataSize())
+
+	if _, err := m.ReadSignedData(data); err != nil {
+		return nil, err
+	}
+
+	return data, nil
+}
+
+// SignedDataSize returns payload size of the request.
+func (m ChangeStateRequest) SignedDataSize() int {
+	return m.GetState().Size()
+}
+
+// ReadSignedData copies payload bytes to passed buffer.
+//
+// If the Request size is insufficient, io.ErrUnexpectedEOF returns.
+func (m ChangeStateRequest) ReadSignedData(p []byte) (int, error) {
+	if len(p) < m.SignedDataSize() {
+		return 0, io.ErrUnexpectedEOF
+	}
+
+	var off int
+
+	off += copy(p[off:], m.GetState().Bytes())
+
+	return off, nil
+}

state/sign_test.go

@@ -47,6 +47,18 @@ func TestRequestSign(t *testing.T) {
 				return new(DumpVarsRequest)
 			},
 		},
+		{
+			constructor: func() sigType {
+				return new(ChangeStateRequest)
+			},
+			payloadCorrupt: []func(sigType){
+				func(s sigType) {
+					req := s.(*ChangeStateRequest)
+
+					req.SetState(req.GetState() + 1)
+				},
+			},
+		},
 	}
 
 	for _, item := range items {

state/types.go

@@ -0,0 +1,24 @@
+package state
+
+import (
+	"encoding/binary"
+)
+
+// SetState is a State field setter.
+func (m *ChangeStateRequest) SetState(st ChangeStateRequest_State) {
+	m.State = st
+}
+
+// Size returns the size of the state binary representation.
+func (ChangeStateRequest_State) Size() int {
+	return 4
+}
+
+// Bytes returns the state binary representation.
+func (x ChangeStateRequest_State) Bytes() []byte {
+	data := make([]byte, x.Size())
+
+	binary.BigEndian.PutUint32(data, uint32(x))
+
+	return data
+}

state/types_test.go

@@ -0,0 +1,18 @@
+package state
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestChangeStateRequestGettersSetters(t *testing.T) {
+	t.Run("state", func(t *testing.T) {
+		st := ChangeStateRequest_State(1)
+		m := new(ChangeStateRequest)
+
+		m.SetState(st)
+
+		require.Equal(t, st, m.GetState())
+	})
+}