rpc: adjust getunclaimedgas RPC-call

Part of #1130

pkg/rpc/client/rpc.go

@@ -2,7 +2,6 @@ package client
 
 import (
 	"encoding/hex"
-	"strconv"
 
 	"github.com/nspcc-dev/neo-go/pkg/core"
 	"github.com/nspcc-dev/neo-go/pkg/core/block"
@@ -308,19 +307,15 @@ func (c *Client) GetTransactionHeight(hash util.Uint256) (uint32, error) {
 }
 
 // GetUnclaimedGas returns unclaimed GAS amount for the specified address.
-func (c *Client) GetUnclaimedGas(address string) (util.Fixed8, error) {
+func (c *Client) GetUnclaimedGas(address string) (result.UnclaimedGas, error) {
 	var (
 		params = request.NewRawParams(address)
-		resp   string
+		resp   result.UnclaimedGas
 	)
 	if err := c.performRequest("getunclaimedgas", params, &resp); err != nil {
-		return 0, err
+		return resp, err
 	}
-	i, err := strconv.ParseInt(resp, 10, 64)
-	if err != nil {
-		return 0, err
-	}
-	return util.Fixed8(i), nil
+	return resp, nil
 }
 
 // GetValidators returns the current NEO consensus nodes information and voting status.

pkg/rpc/client/rpc_test.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"encoding/base64"
 	"encoding/hex"
+	"math/big"
 	"net/http"
 	"net/http/httptest"
 	"strings"
@@ -25,6 +26,7 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/smartcontract/manifest"
 	"github.com/nspcc-dev/neo-go/pkg/util"
 	"github.com/nspcc-dev/neo-go/pkg/vm/opcode"
+	"github.com/pkg/errors"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
@@ -573,11 +575,18 @@ var rpcClientTestCases = map[string][]rpcClientTestCase{
 		{
 			name: "positive",
 			invoke: func(c *Client) (interface{}, error) {
-				return c.GetUnclaimedGas("AGofsxAUDwt52KjaB664GYsqVAkULYvKNt")
+				return c.GetUnclaimedGas("NMipL5VsNoLUBUJKPKLhxaEbPQVCZnyJyB")
 			},
-			serverResponse: `{"jsonrpc":"2.0","id":1,"result":"897299680935"}`,
+			serverResponse: `{"jsonrpc":"2.0","id":1,"result":{"address":"NMipL5VsNoLUBUJKPKLhxaEbPQVCZnyJyB","unclaimed":"897299680935"}}`,
 			result: func(c *Client) interface{} {
-				return util.Fixed8(897299680935)
+				addr, err := address.StringToUint160("NMipL5VsNoLUBUJKPKLhxaEbPQVCZnyJyB")
+				if err != nil {
+					panic(errors.Wrap(err, "failed to parse UnclaimedGas address"))
+				}
+				return result.UnclaimedGas{
+					Address:   addr,
+					Unclaimed: *big.NewInt(897299680935),
+				}
 			},
 		},
 	},

pkg/rpc/response/result/unclaimed_gas.go

@@ -0,0 +1,50 @@
+package result
+
+import (
+	"encoding/json"
+	"errors"
+	"math/big"
+
+	"github.com/nspcc-dev/neo-go/pkg/encoding/address"
+	"github.com/nspcc-dev/neo-go/pkg/util"
+)
+
+// UnclaimedGas response wrapper
+type UnclaimedGas struct {
+	Address   util.Uint160
+	Unclaimed big.Int
+}
+
+// unclaimedGas is an auxiliary struct for JSON marhsalling
+type unclaimedGas struct {
+	Address   string `json:"address"`
+	Unclaimed string `json:"unclaimed"`
+}
+
+// MarshalJSON implements json.Marshaler interface.
+func (g UnclaimedGas) MarshalJSON() ([]byte, error) {
+	gas := &unclaimedGas{
+		Address:   address.Uint160ToString(g.Address),
+		Unclaimed: g.Unclaimed.String(),
+	}
+	return json.Marshal(gas)
+}
+
+// UnmarshalJSON implements json.Unmarshaler interface.
+func (g *UnclaimedGas) UnmarshalJSON(data []byte) error {
+	gas := new(unclaimedGas)
+	if err := json.Unmarshal(data, gas); err != nil {
+		return err
+	}
+	uncl, ok := new(big.Int).SetString(gas.Unclaimed, 10)
+	if !ok {
+		return errors.New("failed to convert unclaimed gas")
+	}
+	g.Unclaimed = *uncl
+	addr, err := address.StringToUint160(gas.Address)
+	if err != nil {
+		return err
+	}
+	g.Address = addr
+	return nil
+}

pkg/rpc/server/server.go

@@ -784,10 +784,15 @@ func (s *Server) getUnclaimedGas(ps request.Params) (interface{}, *response.Erro
 
 	neo, neoHeight := s.chain.GetGoverningTokenBalance(u)
 	if neo.Sign() == 0 {
-		return "0", nil
+		return result.UnclaimedGas{
+			Address: u,
+		}, nil
 	}
 	gas := s.chain.CalculateClaimable(neo, neoHeight, s.chain.BlockHeight()+1) // +1 as in C#, for the next block.
-	return gas.String(), nil
+	return result.UnclaimedGas{
+		Address:   u,
+		Unclaimed: *gas,
+	}, nil
 }
 
 // getValidators returns the current NEO consensus nodes information and voting status.

pkg/rpc/server/server_test.go

@@ -560,13 +560,16 @@ var rpcTestCases = map[string][]rpcTestCase{
 			name:   "positive",
 			params: `["` + testchain.MultisigAddress() + `"]`,
 			result: func(*executor) interface{} {
-				var s string
-				return &s
+				return &result.UnclaimedGas{}
 			},
 			check: func(t *testing.T, e *executor, resp interface{}) {
-				s, ok := resp.(*string)
+				actual, ok := resp.(*result.UnclaimedGas)
 				require.True(t, ok)
-				assert.Equal(t, "36000", *s)
+				expected := result.UnclaimedGas{
+					Address:   testchain.MultisigScriptHash(),
+					Unclaimed: *big.NewInt(36000),
+				}
+				assert.Equal(t, expected, *actual)
 			},
 		},
 	},