cli/query: add height command

cli/query/query.go

@@ -48,6 +48,12 @@ func NewCommands() []cli.Command {
 				Action: queryCommittee,
 				Flags:  options.RPC,
 			},
+			{
+				Name:   "height",
+				Usage:  "Get node height",
+				Action: queryHeight,
+				Flags:  options.RPC,
+			},
 			{
 				Name:   "tx",
 				Usage:  "Query transaction status",
@@ -201,6 +207,33 @@ func queryCommittee(ctx *cli.Context) error {
 	return nil
 }
 
+func queryHeight(ctx *cli.Context) error {
+	var err error
+
+	gctx, cancel := options.GetTimeoutContext(ctx)
+	defer cancel()
+
+	c, err := options.GetRPCClient(gctx, ctx)
+	if err != nil {
+		return cli.NewExitError(err, 1)
+	}
+
+	blockCount, err := c.GetBlockCount()
+	if err != nil {
+		return cli.NewExitError(err, 1)
+	}
+	blockHeight := blockCount - 1 // GetBlockCount returns block count (including 0), not the highest block index.
+
+	fmt.Fprintf(ctx.App.Writer, "Latest block: %d\n", blockHeight)
+
+	stateHeight, err := c.GetStateHeight()
+	if err == nil { // We can be talking to a node without getstateheight request support.
+		fmt.Fprintf(ctx.App.Writer, "Validated state: %d\n", stateHeight.Validated)
+	}
+
+	return nil
+}
+
 func queryVoter(ctx *cli.Context) error {
 	args := ctx.Args()
 	if len(args) == 0 {

cli/query_test.go

@@ -130,3 +130,12 @@ func (e *executor) compareQueryTxVerbose(t *testing.T, tx *transaction.Transacti
 	}
 	e.checkEOF(t)
 }
+
+func TestQueryHeight(t *testing.T) {
+	e := newExecutor(t, true)
+
+	e.Run(t, "neo-go", "query", "height", "--rpc-endpoint", "http://"+e.RPC.Addr)
+	e.checkNextLine(t, `^Latest block: [0-9]+$`)
+	e.checkNextLine(t, `^Validated state: [0-9]+$`)
+	e.checkEOF(t)
+}

docs/cli.md

@@ -466,6 +466,14 @@ You can also vote for candidates if you own NEO:
 
 ### Getting data from chain
 
+#### Node height/validated height
+`query height` returns the latest block and validated state height:
+```
+$ ./bin/neo-go query height -r http://localhost:20332
+Latest block: 11926
+Validated state: 11926
+```
+
 #### Transaction status
 `query tx` provides convenient wrapper over RPC calls to query transaction status.
 ```