rpc: add support of getstateroot to RPC client

pkg/rpc/client/doc.go

@@ -38,6 +38,7 @@ Supported methods
 	getrawmempool
 	getrawtransaction
 	getstateheight
+	getstateroot
 	getstorage
 	gettransactionheight
 	getunclaimedgas

pkg/rpc/client/rpc.go

@@ -471,6 +471,24 @@ func (c *Client) FindStates(stateroot util.Uint256, historicalContractHash util.
 	return resp, nil
 }
 
+// GetStateRootByHeight returns state root for the specified height.
+func (c *Client) GetStateRootByHeight(height uint32) (*state.MPTRoot, error) {
+	return c.getStateRoot(request.NewRawParams(height))
+}
+
+// GetStateRootByBlockHash returns state root for block with specified hash.
+func (c *Client) GetStateRootByBlockHash(hash util.Uint256) (*state.MPTRoot, error) {
+	return c.getStateRoot(request.NewRawParams(hash))
+}
+
+func (c *Client) getStateRoot(params request.RawParams) (*state.MPTRoot, error) {
+	var resp = new(state.MPTRoot)
+	if err := c.performRequest("getstateroot", params, resp); err != nil {
+		return nil, err
+	}
+	return resp, nil
+}
+
 // GetStateHeight returns current validated and local node state height.
 func (c *Client) GetStateHeight() (*result.StateHeight, error) {
 	var (

pkg/rpc/client/rpc_test.go

@@ -769,6 +769,47 @@ var rpcClientTestCases = map[string][]rpcClientTestCase{
 			},
 		},
 	},
+	"getstateroot": {
+		{
+			name: "positive, by height",
+			invoke: func(c *Client) (interface{}, error) {
+				return c.GetStateRootByHeight(5)
+			},
+			serverResponse: `{"id":1,"jsonrpc":"2.0","result":{"version":0,"index":5,"roothash":"0x65d19151694321e70c6d184b37a2bcf7af4a2c60c099af332a4f7815e3670686","witnesses":[]}}`,
+			result: func(c *Client) interface{} {
+				h, err := util.Uint256DecodeStringLE("65d19151694321e70c6d184b37a2bcf7af4a2c60c099af332a4f7815e3670686")
+				if err != nil {
+					panic(err)
+				}
+				return &state.MPTRoot{
+					Version: 0,
+					Index:   5,
+					Root:    h,
+					Witness: []transaction.Witness{},
+				}
+			},
+		},
+		{
+			name: "positive, by hash",
+			invoke: func(c *Client) (interface{}, error) {
+				hash, err := util.Uint256DecodeStringLE("86fe1061140b2ea791b0739fb9732abc6e5e47de4927228a1ac41de3d93eb7cb")
+				if err != nil {
+					panic(err)
+				}
+				return c.GetStateRootByBlockHash(hash)
+			},
+			serverResponse: `{"id":1,"jsonrpc":"2.0","result":{"version":0,"index":5,"roothash":"0x65d19151694321e70c6d184b37a2bcf7af4a2c60c099af332a4f7815e3670686","witnesses":[]}}`,
+			result: func(c *Client) interface{} {
+				h, _ := util.Uint256DecodeStringLE("65d19151694321e70c6d184b37a2bcf7af4a2c60c099af332a4f7815e3670686")
+				return &state.MPTRoot{
+					Version: 0,
+					Index:   5,
+					Root:    h,
+					Witness: []transaction.Witness{},
+				}
+			},
+		},
+	},
 	"getstate": {
 		{
 			name: "positive",