feat: Add CLI commands: 1) simulate a transaction, 2) query block results

CHANGELOG.md

@@ -40,6 +40,8 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### Features
 
+* (cli) [#16887](https://github.com/cosmos/cosmos-sdk/pull/16887) Add two new CLI commands: `tx simulate` for simulating a transaction; `query block-results` for querying CometBFT RPC for block results.
+
 ### Improvements
 
 * (cli) [#16856](https://github.com/cosmos/cosmos-sdk/pull/16856) Improve `simd prune` UX by using the app default home directory and set pruning method as first variable argument (defaults to default).

client/cometbft.go

@@ -16,6 +16,7 @@ type CometRPC interface {
 	Status(context.Context) (*coretypes.ResultStatus, error)
 	Block(ctx context.Context, height *int64) (*coretypes.ResultBlock, error)
 	BlockByHash(ctx context.Context, hash []byte) (*coretypes.ResultBlock, error)
+	BlockResults(ctx context.Context, height *int64) (*coretypes.ResultBlockResults, error)
 	BlockchainInfo(ctx context.Context, minHeight, maxHeight int64) (*coretypes.ResultBlockchainInfo, error)
 	Commit(ctx context.Context, height *int64) (*coretypes.ResultCommit, error)
 	Tx(ctx context.Context, hash []byte, prove bool) (*coretypes.ResultTx, error)

server/cmt_cmds.go

@@ -1,6 +1,8 @@
 package server
 
 import (
+	"context"
+	"encoding/json"
 	"fmt"
 	"strconv"
 	"strings"
@@ -206,18 +208,13 @@ $ %s query block --%s=%s <hash>
 					return fmt.Errorf("argument should be a block height")
 				}
 
-				var height *int64
-
 				// optional height
+				var height *int64
 				if len(args) > 0 {
-					h, err := strconv.Atoi(args[0])
+					height, err = parseOptionalHeight(args[0])
 					if err != nil {
 						return err
 					}
-					if h > 0 {
-						tmp := int64(h)
-						height = &tmp
-					}
 				}
 
 				output, err := rpc.GetBlockByHeight(clientCtx, height)
@@ -261,6 +258,70 @@ $ %s query block --%s=%s <hash>
 	return cmd
 }
 
+// QueryBlockResultCmd implements the default command for a BlockResults query.
+func QueryBlockResultsCmd() *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "block-results [height]",
+		Short: "Query for a committed block's results by height",
+		Long:  "Query for a specific committed block's results using the CometBFT RPC `block_results` method",
+		Args:  cobra.RangeArgs(0, 1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			clientCtx, err := client.GetClientQueryContext(cmd)
+			if err != nil {
+				return err
+			}
+
+			node, err := clientCtx.GetNode()
+			if err != nil {
+				return err
+			}
+
+			// optional height
+			var height *int64
+			if len(args) > 0 {
+				height, err = parseOptionalHeight(args[0])
+				if err != nil {
+					return err
+				}
+			}
+
+			blockRes, err := node.BlockResults(context.Background(), height)
+			if err != nil {
+				return err
+			}
+
+			// coretypes.ResultBlockResults doesn't implement proto.Message interface
+			// so we can't print it using clientCtx.PrintProto
+			// we choose to serialize it to json and print the json instead
+			blockResStr, err := json.Marshal(blockRes)
+			if err != nil {
+				return err
+			}
+
+			return clientCtx.PrintString(string(blockResStr) + "\n")
+		},
+	}
+
+	flags.AddQueryFlagsToCmd(cmd)
+
+	return cmd
+}
+
+func parseOptionalHeight(heightStr string) (*int64, error) {
+	h, err := strconv.Atoi(heightStr)
+	if err != nil {
+		return nil, err
+	}
+
+	if h == 0 {
+		return nil, nil
+	}
+
+	tmp := int64(h)
+
+	return &tmp, nil
+}
+
 func BootstrapStateCmd(appCreator types.AppCreator) *cobra.Command {
 	cmd := &cobra.Command{
 		Use:   "bootstrap-state",

simapp/simd/cmd/root.go

@@ -246,6 +246,7 @@ func queryCommand() *cobra.Command {
 		authcmd.QueryTxsByEventsCmd(),
 		server.QueryBlocksCmd(),
 		authcmd.QueryTxCmd(),
+		server.QueryBlockResultsCmd(),
 	)
 
 	return cmd
@@ -270,6 +271,7 @@ func txCommand() *cobra.Command {
 		authcmd.GetEncodeCommand(),
 		authcmd.GetDecodeCommand(),
 		authcmd.GetAuxToFeeCommand(),
+		authcmd.GetSimulateCmd(),
 	)
 
 	return cmd

simapp/simd/cmd/root_v2.go

@@ -263,6 +263,7 @@ func queryCommand() *cobra.Command {
 		authcmd.QueryTxsByEventsCmd(),
 		server.QueryBlocksCmd(),
 		authcmd.QueryTxCmd(),
+		server.QueryBlockResultsCmd(),
 	)
 
 	return cmd
@@ -287,6 +288,7 @@ func txCommand() *cobra.Command {
 		authcmd.GetEncodeCommand(),
 		authcmd.GetDecodeCommand(),
 		authcmd.GetAuxToFeeCommand(),
+		authcmd.GetSimulateCmd(),
 	)
 
 	return cmd

x/auth/client/cli/tx_simulate.go

@@ -0,0 +1,101 @@
+package cli
+
+import (
+	"strings"
+
+	"github.com/spf13/cobra"
+
+	"github.com/cosmos/cosmos-sdk/client"
+	"github.com/cosmos/cosmos-sdk/client/flags"
+	"github.com/cosmos/cosmos-sdk/client/tx"
+	authclient "github.com/cosmos/cosmos-sdk/x/auth/client"
+)
+
+// GetSimulateCmd returns a command that simulates whether a transaction will be
+// successful.
+func GetSimulateCmd() *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "simulate /path/to/unsigned-tx.json --from keyname",
+		Short: "Simulate the gas usage of a transaction",
+		Long: strings.TrimSpace(`Simulate whether a transaction will be successful:
+
+- if successful, the simulation result is printed, which includes the gas
+  consumption, message response data, and events emitted;
+- if unsuccessful, the error message is printed.
+
+The user must provide the path to a JSON-encoded unsigned transaction, typically
+generated by any transaction command with the --generate-only flag. It should
+look like below. Note that the "signer_infos" and "signatures" fields are left
+empty; they will be auto-populated by dummy data for simulation purpose.
+
+{
+  "body": {
+    "messages": [
+      {
+        "@type": "/cosmos.bank.v1beta1.MsgSend",
+        "from_address": "cosmos1...",
+        "to_address": "cosmos1...",
+        "amount": [
+          {
+            "denom": "utoken",
+            "amount": "12345"
+          }
+        ]
+      }
+    ],
+    "memo": "",
+    "timeout_height": "0",
+    "extension_options": [],
+    "non_critical_extension_options": []
+  },
+  "auth_info": {
+    "signer_infos": [],
+    "fee": {
+      "amount": [],
+      "gas_limit": "200000",
+      "payer": "",
+      "granter": ""
+    },
+    "tip": null
+  },
+  "signatures": []
+}
+
+The --from flag is mandatory, as the signer account's correct sequence number is
+necessary for simulation.
+`),
+		Args: cobra.ExactArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			clientCtx, err := client.GetClientTxContext(cmd)
+			if err != nil {
+				return err
+			}
+
+			txf, err := tx.NewFactoryCLI(clientCtx, cmd.Flags())
+			if err != nil {
+				return err
+			}
+
+			txf, err = txf.Prepare(clientCtx)
+			if err != nil {
+				return err
+			}
+
+			stdTx, err := authclient.ReadTxFromFile(clientCtx, args[0])
+			if err != nil {
+				return err
+			}
+
+			simRes, _, err := tx.CalculateGas(clientCtx, txf, stdTx.GetMsgs()...)
+			if err != nil {
+				return err
+			}
+
+			return clientCtx.PrintProto(simRes)
+		},
+	}
+
+	flags.AddTxFlagsToCmd(cmd)
+
+	return cmd
+}